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MODULE DTIVIEW

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FUNCTION

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FORMAT

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PROMPTS

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DESCRIPTION

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GENERAL

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PROJECTION TRANSFORMATIONS

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TERRAIN VIEW GENERATION

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HIDDEN LINE REMOVAL

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SIMPLE PROFILE BETWEEN TWO DTM POINTS

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PICTURE AND PLANES

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COLOUR TABLES

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OVERLAY OF IFF DATA ON A TERRAIN VIEW

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DISPLAY ANNOTATION

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PLOTTING AND MOVEMENT OF SYMBOLS ON A TERRAIN VIEW

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RESTRICTION OF VISIBILITY (FOG)

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USE OF A DIGITISING TABLE AND PUCK BUTTONS

DTIVIEW COMMANDS

_@ COMMAND

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_@

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FORMAT: _@ file-spec

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Command parameters:

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DESCRIPTION:

DTIVIEW offers the facility of command input from an indirect command file. The '@' character preceding a file-spec will cause DTIVIEW to open and read commands from the specified file until:

Nested command files are not supported (i_.e_. a command file containing an '@' command), although sequential '@' commands are supported when read from SYS$COMMAND.

As an aid to batch log interpretation DTIVIEW will echo all commands read from an indirect command file.

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Messages:

The following messages are specific to the _@ command:


*** ERROR *** Specifying command @
Command file specification is missing

*** ERROR *** Specifying command @
Unable to open indirect command file 'file-spec'

*** ERROR *** Specifying command @
Nested command files not supported

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Examples:


DTIVIEW> @PRESETS<CR>
DTIVIEW> ENABLE GRAPHICS
DTIVIEW> FILEIN AREA1 DTI file LSL$DTI:AREA1.DTI;0 opened for read Header : MIKE Data: WORD Units are DTI Matrix Values Matrix Coverage SW: 1 1 NE: 45 40 Matrix Interval E: 1 N: 1 Value Range : 378 to 526
DTIVIEW> WINDOW 1 1 30 30
DTIVIEW> DIRECTION SOUTH
DTIVIEW> RETURN
DTIVIEW>

_! COMMAND

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_!

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FORMAT: _! [comment text]

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Command parameters:

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DESCRIPTION:

An exclamation mark is the standard MATRIX package comment delimiter. All text (and numbers) which lie to the right of a '!' character are excluded from command interpretation. Comments are useful for annotating command procedures used in batch processing etc.

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Messages: None.

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Examples:


DTIVIEW> FILEIN TEST !open the file<CR>
DTIVIEW> !Define a window<CR>
DTIVIEW> WINDOW 1 1 10 10<CR>
DTIVIEW>

CLEAR COMMAND

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CLEAR

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FORMAT:		 CLEAR 

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Command parameters: _None

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DESCRIPTION:

The CLEAR command is used to clear the display screen of a graphics device.

The command operates on both Picture 1 and Picture 2. If you wish to clear pictures independently, the command CLEAR PICTURE should be used.

If a divided screen is selected, then the command CLEAR QUADRANT may be used to clear a particular quadrant of the screen.

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Messages:

The following error messages are specific to the CLEAR command:


*** ERROR *** Specifying command CLEAR
No graphics device is currently enabled

*** ERROR *** Specifying command CLEAR
Command qualifiers are PICTURE or QUADRANT

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Examples:

DTIVIEW>CLEAR
DTIVIEW>

CLEAR QUADRANT COMMAND

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CLEAR QUADRANT

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FORMAT:		 CLEAR QUADRANT quadrant_number

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Command parameters:

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DESCRIPTION:

The CLEAR QUADRANT command is used to clear a single quadrant of a graphics screen. The quadrant_number parameter specifies which quadrant is to be cleared.
The command is only valid if a divided screen is currently selected. The command operates on both Picture 1 and Picture 2.

To clear the whole screen (ie. all quadrants) the command CLEAR without the qualifier QUADRANT should be given.

Note that it is not possible to clear a single quadrant on a TEKTRONIX 4014 display.

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Messages:

The following error messages are specific to the CLEAR and CLEAR QUADRANT command:


*** ERROR *** Specifying command CLEAR
No graphics device is currently enabled

*** ERROR *** Specifying command CLEAR
Command qualifiers are PICTURE or QUADRANT

*** ERROR *** Specifying command CLEAR QUADRANT
A divided screen is not enabled

*** ERROR *** Specifying command CLEAR QUADRANT
Command requires a quadrant number in the range 1 to 4

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Examples:

DTIVIEW>ENABLE DIVIDE
DTIVIEW>CLEAR QUADRANT 2
DTIVIEW>

CLEAR PICTURE COMMAND

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CLEAR PICTURE

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FORMAT:		 CLEAR PICTURE picture_number

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Command parameters:

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DESCRIPTION:

The CLEAR PICTURE command is used to clear the bit-planes of a graphics device that are currently allocated to the specified picture.

The number of bit-planes allocated to picture 1 and picture 2 is determined using the PLANES command. By default 5 planes (bit-planes 1 to 5) are used for Picture 1, and the remaining 3 planes (bit-planes 6 to 8) are used for Picture 2. An isometric or perspective terrain view is drawn into Picture 1, while any vector overlay information or annotation drawn using the OVERLAY and DRAW LABEL commands, is displayed in Picture 2.
A terrain view may therefore be cleared independently of any overlay using the command CLEAR PICTURE 1, while any IFF overlay may be cleared independently from the terrain base using the command CLEAR PICTURE 2. To clear both pictures (ie. all bit-planes of a graphics display), the command CLEAR should be used.

Note that this command is not applicable if the output graphics device is a TEKTRONIX 4014, or if the device is configured with only 4 bit-planes.

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Messages:

The following error messages are specific to the CLEAR and CLEAR PICTURE commands:


*** ERROR *** Specifying command CLEAR
No graphics device is currently enabled

*** ERROR *** Specifying command CLEAR
Command qualifiers are PICTURE or QUADRANT

*** ERROR *** Specifying command CLEAR PICTURE
Command requires 1 integer argument

*** ERROR *** Specifying command CLEAR PICTURE
Command requires a picture number of 1 or 2

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Examples:

DTIVIEW>CLEAR PICTURE 1
DTIVIEW>

COLOURS COMMAND

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COLOURS

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FORMAT:		 COLOURS number

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Command parameters:

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DESCRIPTION:

The COLOURS command defines the number of colours used to draw a terrain view on a colour graphics device.

By default, DTIVIEW allocates 5 bit-planes of a graphics device to the terrain view, and uses the the colour table file LSL$LOOKUP:DTIVIEW5.DAT. This file contains RGB definitions for 32 PICTURE 1 colours, and 7 overlay colours. The first 3 entries define the colours black, white and blue which are used specially by the program; the remaining 29 entries define a series of colours that are used when drawing the isometric or perspective view profile lines. Different colours are used to represent different height levels.
By default therefore the terrain view will be drawn using 29 colours.
Using the COLOURS command, it is possible to change this default, and specify how many colours are used when displaying a terrain view. For example, the command COLOURS 4 will select the use of the first 4 non-special colours in the currently selected colour table.

A common use for the command is to restrict the number of colours used in drawing the terrain base, so that any vector data overlaid on the view may be easily seen.

Note that redefining the number of colours, may change the height interval value previously set by the ZSTEP command, and that the PLANES command will automatically reset the number of colours to the maximum allowable for the bit-plane setting.

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Messages:

The following error messages are specific to the COLOURS command:


*** ERROR *** Specifying command COLOURS
Command requires 1 integer argument

*** ERROR *** Specifying command COLOURS
Number of colours should be in the range 1 to 

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Examples:

DTIVIEW>COLOURS 13
DTIVIEW>

DESELECT FC COMMAND

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DESELECT FC

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FORMAT:         DESELECT FC feature_code [,...]

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Command parameters:

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DESCRIPTION:

The DESELECT FC command is used to exclude IFF features from overlay on an isometric or perspective view. Features are excluded on the basis of their feature code.

By default DTIVIEW will use all features within an IFF file.

Use of the SHOW SELECTIONS command is recommended to display feature selections before the OVERLAY command is given.

The DESELECT FC command is only valid if the ENABLE OVERLAY command has been previously given, and the FRT command has been used to select a Feature Representation Table.

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Messages:

The following error messages are specific to the DESELECT and DESELECT FC commands:


*** ERROR *** Specifying command DESELECT
Overlay options are not currently enabled

*** ERROR *** Specifying command DESELECT
Command qualifiers are FC, FSN, or LAYER             

*** ERROR *** Specifying command DESELECT
Illegal feature code

*** ERROR *** Specifying command DESELECT FC
No FRT has been read

*** ERROR *** Specifying command DESELECT FC
No groups have been defined in the FRT

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Examples:

DTIVIEW>DESELECT FC 1
DTIVIEW>DESELECT FC RAILWAYS
DTIVIEW>DESELECT FC RIVERS 7-10,56-78
DTIVIEW>

DESELECT FSN COMMAND

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DESELECT FSN

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FORMAT:	        DESELECT FSN fsn [,...]

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Command parameters:

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DESCRIPTION:

The DESELECT FSN command is used to exclude IFF features from overlay on an isometric or perspective view. Features are excluded on the basis of their feature serial number.

By default DTIVIEW will use all features within an IFF file.

Use of the SHOW SELECTIONS command is recommended to display feature selections before the OVERLAY command is given.

The DESELECT FSN command is only valid if the ENABLE OVERLAY command has been previously given.

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Messages:

The following error messages are specific to the DESELECT and DESELECT FSN commands:


*** ERROR *** Specifying command DESELECT
Command is not valid unless the ENABLE OVERLAY command has been given

*** ERROR *** Specifying command DESELECT
Command qualifiers are FC, FSN, or LAYER             

*** ERROR *** Specifying command DESELECT FSN
Illegal FSN number

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Examples:

DTIVIEW>DESELECT FSN 4
DTIVIEW>DESELECT FSN 7-10,56-78
DTIVIEW>

DESELECT LAYER COMMAND

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DESELECT LAYER

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FORMAT:	        DESELECT LAYER layer [,...]

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Command parameters:

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DESCRIPTION:

The DESELECT LAYER command is used to exclude IFF features from overlay on an isometric or perspective view. Features are excluded on the basis of IFF layer.

By default DTIVIEW will use all features within an IFF file.

Use of the SHOW SELECTIONS command is recommended to display feature selections before the OVERLAY command is given.

The DESELECT LAYER command is only valid if the ENABLE OVERLAY command has been previously given.

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Messages:

The following error messages are specific to the DESELECT and DESELECT LAYER commands:


*** ERROR *** Specifying command DESELECT
Command is not valid unless the ENABLE OVERLAY command has been given

*** ERROR *** Specifying command DESELECT
Command qualifiers are FC, FSN, or LAYER             

*** ERROR *** Specifying command DESELECT
Illegal layer number

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Examples:

DTIVIEW>DESELECT LAYER 7
DTIVIEW>DESELECT LAYER 1,7-10
DTIVIEW>

DIRECTION COMMAND

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DIRECTION

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FORMAT:	        DIRECTION  direction

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Command parameters:

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DESCRIPTION:

The DIRECTION command defines the direction of view, and therefore controls the order in which the DTM elevation values are sampled.
For a direction of NORTH or SOUTH, the DTM is sampled row by row; for a direction of EAST or WEST, the DTM is sampled column by column.

The default viewing direction is from the west.

Use of the SHOW VIEW command is recommended to check on current viewing parameters before an isometric or perspective view is generated.

If the DTIVIEW menu has been set up on a digitising table using the SETUP MENU command, the direction of view may be entered by means of the 4 boxes labelled N E S W.

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Messages:

The following error message is specific to the DIRECTION command:


*** ERROR *** Specifying command DIRECTION
Command requires a keyword qualifier of NORTH, SOUTH, EAST or WEST.

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Examples:

DTIVIEW>DIRECTION EAST
DTIVIEW>

DISABLE ABSOLUTE COMMAND

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DISABLE ABSOLUTE

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FORMAT: DISABLE ABSOLUTE

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Command parameters: None.

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DESCRIPTION:

DISABLE ABSOLUTE cancels a previous ENABLE ABSOLUTE command. If DISABLE ABSOLUTE is given, then coordinate values required by the WINDOW, PROFILE and SYMBOL POSITION commands, supplied in metre or projection units, must be specified as an offset from the SW corner of the matrix. Coordinates supplied with the IFFWINDOW command should similarly be specified as an offset from the SW corner of the IFF file area.
By default window values should be specified as absolute coordinates.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:


DTIVIEW> DISABLE ABSOLUTE<CR>
DTIVIEW>

DISABLE AUTOSCALE COMMAND

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DISABLE AUTOSCALE

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FORMAT: DISABLE AUTOSCALE

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Command parameters: _None

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DESCRIPTION:

DISABLE AUTOSCALE deselects the automatic scaling and positioning of an isometric or perspective view on a graphics screen. The command therefore cancels any previous ENABLE AUTOSCALE command.

If the DISABLE AUTOSCALE is given, it is necessary to specifically set the position and scale of the view on the graphics screen using the SET SCALE and SET ORIGIN commands.

By default the scaling and positioning of the plot automatically by the program is enabled.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE AUTOSCALE
DTIVIEW>

DISABLE BATHYMETRY COMMAND

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DISABLE BATHYMETRY

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FORMAT:		 DISABLE BATHYMETRY

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Command parameters: _None

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DESCRIPTION:

The DISABLE BATHYMETRY command cancels any previous ENABLE BATHYMETRY command. It is therefore used to reselect the normal modelling options that are appropriate to a DTM containing positive height values. The command also causes a default colour file that is appropriate to the current PLANES setting to be selected (eg. LSL$LOOKUP:DTIVIEW5.DAT if 5 planes are selected).

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE BATHYMETRY
DTIVIEW>

DISABLE COLOUR_IFF COMMAND

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DISABLE COLOUR_IFF

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FORMAT:		 DISABLE COLOUR_IFF

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Command parameters: _None

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DESCRIPTION:

The DISABLE COLOUR_IFF command cancels any previous ENABLE COLOUR_IFF command. It is therefore used to deselect the option of producing an output IFF feature in which a new feature is started whenever the colour of the vectors defining a profile changes.

If this option is deselected, then only parts of the profile that represent sea, land or heights outside the height range, will be distinguished in the IFF file.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE COLOUR_IFF
DTIVIEW>

DISABLE DIVIDE COMMAND

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DISABLE DIVIDE

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FORMAT:		 DISABLE DIVIDE

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Command parameters: _None

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DESCRIPTION:

The DISABLE DIVIDE command cancels any previous ENABLE DIVIDE command. It is therefore used to reselect the use of an undivided (ie. full) display screen.

The SHOW ENABLE command may be used to check on the status of the option.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE DIVIDE
DTIVIEW>

DISABLE FISHNET COMMAND

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DISABLE FISHNET

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FORMAT:		 DISABLE FISHNET

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Command parameters: _None

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DESCRIPTION:

DISABLE FISHNET deselects the option to produce a fishnet representation of the terrain view.

By default the option is not selected.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE FISHNET
DTIVIEW>

DISABLE FOG COMMAND

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DISABLE FOG

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FORMAT:		DISABLE FOG

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Command parameters: None.

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DESCRIPTION:

The DISABLE FOG command is used to disable any current visibility restriction. The command is therefore used to cancel a previous ENABLE FOG command.

After using the DISABLE FOG command, other commands that are relevant to the fog option are invalid.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating a perspective view.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Example:

DTIVIEW>DISABLE FOG
DTIVIEW>

DISABLE GRAPHICS COMMAND

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DISABLE GRAPHICS

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FORMAT:		 DISABLE GRAPHICS

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Command parameters: _None

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DESCRIPTION:

DISABLE GRAPHICS deselects output to all workstation graphics devices when the ISOMETRIC, PERSPECTIVE, PROFILE or OVERLAY commands are given.
It is therefore used to cancel any previous ENABLE GRAPHICS command.

The command is only useful when used with the ENABLE IFF_OUTPUT command.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE GRAPHICS
DTIVIEW>

DISABLE IFF_OUTPUT COMMAND

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DISABLE IFF_OUTPUT

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FORMAT:		 DISABLE IFF_OUTPUT

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Command parameters: _None

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DESCRIPTION:

DISABLE IFF_OUTPUT deselects the option of directing output to an IFF file when the ISOMETRIC, PERSPECTIVE, PROFILE or OVERLAY commands are given.
It is therefore used to cancel any previous ENABLE IFF_OUTPUT command.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE IFF_OUTPUT
DTIVIEW>

DISABLE OVERLAY COMMAND

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DISABLE OVERLAY

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FORMAT:		DISABLE OVERLAY

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Command parameters: None.

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DESCRIPTION:

The DISABLE OVERLAY command is used to disable the overlay of vector data on an isometric or perspective terrain view. The command is therefore used to cancel any previous ENABLE OVERLAY command.

After using the DISABLE OVERLAY command, other commands that are relevant to the overlay of vector data on a terrain view are invalid.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Example:

DTIVIEW>DISABLE OVERLAY
DTIVIEW>

DISABLE PICTURE COMMAND

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DISABLE PICTURE

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FORMAT:		 DISABLE PICTURE picture_number

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Command parameters:

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DESCRIPTION:

The DISABLE PICTURE command is used to deselect (make invisible) the bit-planes of a graphics device that are currently allocated to the specified picture.

The number of bit-planes allocated to picture 1 and picture 2 is determined using the PLANES command.

An isometric or perspective terrain view is drawn into Picture 1, while any vector overlay information or annotation drawn using the OVERLAY and DRAW LABEL commands, is displayed in Picture 2. Giving the command DISABLE PICTURE 2 will therefore make invisible any vector overlay or annotation. PICTURE 2 may be reselected (made visible) using the command ENABLE PICTURE 2.

Note that this command is not applicable if the graphics device is a TEKTRONIX 4014, or if the device is configured with 4 bit-planes.

The SHOW ENABLE command may be used to check on the status of the 2 pictures.

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Messages:

The following error message is specific to the DISABLE and DISABLE PICTURE commands:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

*** ERROR *** Specifying command DISABLE PICTURE
Command requires an integer argument

*** ERROR *** Specifying command DISABLE PICTURE
Command requires a picture number of 1 or 2

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Examples:

DTIVIEW>DISABLE PICTURE 2
DTIVIEW>

DISABLE PRIMARY COMMAND

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DISABLE PRIMARY

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FORMAT:		 DISABLE PRIMARY

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Command parameters: _None

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DESCRIPTION:

DISABLE PRIMARY deselects the use of a workstation's primary graphics device.
It is therefore used to cancel any previous ENABLE PRIMARY command.

The command is only useful on workstations that are configured with two display devices. On a workstation with a single graphics display use of the command DISABLE GRAPHICS is to be preferred.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE PRIMARY
DTIVIEW>

DISABLE SECONDARY COMMAND

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DISABLE SECONDARY

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FORMAT:		 DISABLE SECONDARY

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Command parameters: _None

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DESCRIPTION:

DISABLE SECONDARY deselects the use of a workstation's secondary graphics device.
It is therefore used to cancel any previous ENABLE SECONDARY command.

The command is only useful on workstations that are configured with two display devices. On a workstation with a single graphics display the command will be ignored.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Examples:

DTIVIEW>DISABLE SECONDARY
DTIVIEW>

DISABLE SYMBOLS COMMAND

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DISABLE SYMBOLS

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FORMAT:		DISABLE SYMBOLS

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Command parameters: None.

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DESCRIPTION:

The DISABLE SYMBOLS command is used to disable the plotting of symbols on an isometric or perspective terrain view. The command is therefore used to cancel any previous ENABLE SYMBOLS command.

After using the DISABLE SYMBOLS command, other commands that are relevant to the plotting of symbols on a terrain view, become invalid.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

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Messages:

The following error message is specific to the DISABLE command:


*** ERROR *** Specifying command DISABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

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Example:

DTIVIEW>DISABLE SYMBOLS
DTIVIEW>

DISABLE TABLE COMMAND

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DISABLE TABLE

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FORMAT:		DISABLE TABLE

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Command parameters: _None

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DESCRIPTION:

The DISABLE TABLE command turns off input from the digitising table. If table input is disabled then DTIVIEW will accept commands only from the terminal.

Input from the table can be reselected using the ENABLE TABLE command.

The SHOW ENABLE command may be used to check on the status of table input.

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Messages:

The following error messages are specific to the ENABLE and ENABLE TABLE commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE
 

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Example:

DTIVIEW>DISABLE TABLE
DTIVIEW>

DISTANCE COMMAND

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DISTANCE

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FORMAT:	        DISTANCE distance

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Command parameters:

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DESCRIPTION:

The DISTANCE command defines the distance of the view point in metres from the nearest point in the DTM rectangular area of interest. The parameter is used when generating a perspective view.

The default distance is 300.0 metres.

Use of the SHOW VIEW command is recommended to check on the status of this parameter before a perspective view is generated.

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Messages:

The following error message is specific to the DISTANCE command:


*** ERROR *** Specifying command DISTANCE
Command requires 1 real argument

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Examples:

DTIVIEW>DISTANCE 450.2
DTIVIEW>

DRAW LABEL COMMAND

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DRAW LABEL

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FORMAT:		DRAW LABEL text

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Command parameters:

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DESCRIPTION:

DRAW LABEL is used to output a text string to a graphics screen. Commonly it is used to annotate a terrain view with a title and place name details.

If the workstation colour graphics device is configured with 8 bit- planes, any annotation will be written to the bit-planes allocated to Picture 2. When using a 4 plane device, the annotation is written to Picture 1.

The specified text is written at the current label position, and in the current label colour and label size. These parameters may be varied using the appropriate LABEL commands.

On most devices, text output using the DRAW LABEL command may be cleared independently of the terrain view using the LABEL CLEAR or CLEAR PICTURE 2 commands. This is not possible for text output to a Tektronix 4014 display, or when using a display device configured with only 4 bit-planes.

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Messages:

The following error messages are specific to the DRAW and DRAW LABEL commands:


*** ERROR *** Specifying command DRAW
No graphics device is currently enabled

*** ERROR *** Specifying command DRAW
Command qualifiers are LABEL or LEGEND

*** ERROR *** Specifying command DRAW LABEL
Command requires a text string of up to 80 characters

*** ERROR *** Specifying command DRAW LABEL
More than 80 characters in text string

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Examples:

DTIVIEW>DRAW LABEL An example terrain view<CR>
DTIVIEW>

DRAW LEGEND COMMAND

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DRAW LEGEND

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FORMAT:		 DRAW LEGEND

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Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The DRAW LEGEND command is used to generate a legend on a graphics screen after an isometric or perspective view has been drawn.

The legend relates the colours used in the terrain view to their respective height ranges.

By default the legend is drawn in the bottom lefthand corner of the screen if a full screen is selected, or in the bottom lefthand corner of the currently selected quadrant.

The position of the legend on the screen may be changed by using the LEGEND POSITION command, while the size of the legend boxes may be controlled using the LEGEND SIZE command.

A legend cannot be generated on a TEKTRONIX 4014 monochrome display.

--------------------------------------------------------------------------------
Messages:

The following error message are specific to the DRAW and DRAW LEGEND commands:


*** ERROR *** Specifying command DRAW
Command qualifiers are LABEL or LEGEND

*** ERROR *** Specifying command DRAW LEGEND
No graphics device is currently enabled

*** ERROR *** Specifying command DRAW LEGEND
No legend can be shown on a TEKTRONIX 4014

--------------------------------------------------------------------------------
Examples:

DTIVIEW>DRAW LEGEND
DTIVIEW>

ENABLE ABSOLUTE COMMAND

--------------------------------------------------------------------------------
ENABLE ABSOLUTE

--------------------------------------------------------------------------------
FORMAT: ENABLE ABSOLUTE

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

If ENABLE ABSOLUTE is given, then coordinate values required by the WINDOW, PROFILE or SYMBOL POSITION commands, supplied in metre or projection units, must be specified as absolute (rather than relative) coordinate values. Coordinates for the IFFWINDOW command should also be supplied as absolute values.

For example if the projection indicates U.K. National Grid, then the WINDOW values may be specified as 6 figure National Grid coordinates.
By default window values should be specified as absolute coordinates.

This option can be disabled using the DISABLE ABSOLUTE command.

--------------------------------------------------------------------------------
Messages:

The following error message is specific to the ENABLE command:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

--------------------------------------------------------------------------------
Examples:


DTIVIEW> ENABLE ABSOLUTE<CR>
DTIVIEW>

ENABLE AUTOSCALE COMMAND

--------------------------------------------------------------------------------
ENABLE AUTOSCALE

--------------------------------------------------------------------------------
FORMAT: ENABLE AUTOSCALE

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

ENABLE AUTOSCALE ensures that any isometric or perspective view drawn on a graphics screen, is correctly scaled and positioned on the screen.
Using ENABLE AUTOSCALE a view is drawn so that it is positioned in the centre of the screen, and extends almost to the edge of the screen in the longer of the plot axes.
If a quartered screen has been selected using the ENABLE DIVIDE command, the view is positioned in the centre of the currently selected quadrant, and scaled to fit the quadrant.

In order to determine the x and y plot coordinate ranges, two passes are made through the data in the currently defined DTM area of interest.
The first pass determines the coordinate ranges without output to the screen, and sets up the drawing scaling factor and origin. The drawing origin in normalised device coordinates (ie. in the range 0.0 to 1.0) and the drawing scaling factor are displayed on the terminal.
The second pass, draws the isometric or perspective view on the graphics screen.

By default the scaling and positioning of the terrain view automatically by the program is enabled. The option may be deselected by means of the DISABLE AUTOSCALE command; if this command is used, it is necessary to supply drawing origin and scaling values using the SET ORIGIN and SET SCALE commands.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

--------------------------------------------------------------------------------
Messages:

The following error message is specific to the ENABLE command:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE AUTOSCALE
DTIVIEW>

ENABLE BATHYMETRY COMMAND

--------------------------------------------------------------------------------
ENABLE BATHYMETRY

--------------------------------------------------------------------------------

FORMAT:		 ENABLE BATHYMETRY

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The ENABLE BATHYMETRY command selects the program's special options for generating and displaying a view using bathymetric data. The option should be enabled if the input DTM contains a large number of negative height values defining the depth and shape of the sea floor.

When using this option, only nodes in the DTM that have negative heights are modelled. DTM nodes with positive heights are not modelled, so that the land surface will always appear flat. Any vertical exaggeration value is applied only to nodes with negative heights.

Selection of the option also causes a special colour table UNDERSEA.DAT to be read from the search list LSL$LOOKUP, so that when the view is drawn on a screen, different depths appear in different shades of blue, and all land appears in brown. The display colours may be changed by editing the RGB values in this file.

The normal modelling and colour table options may be reselected by means of the command DISABLE BATHYMETRY. By default the bathymetry option is not selected.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

--------------------------------------------------------------------------------
Messages:

The following messages are specific to the ENABLE and ENABLE BATHYMETRY commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

*** WARNING *** Current DTM does not contain any negative heights

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE BATHYMETRY
DTIVIEW>

ENABLE COLOUR_IFF COMMAND

--------------------------------------------------------------------------------
ENABLE COLOUR_IFF

--------------------------------------------------------------------------------

FORMAT:		 ENABLE COLOUR_IFF

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The ENABLE COLOUR_IFF command selects the option of producing an IFF file in which a new feature is started whenever the colour of vectors defining a profile changes. The command is used in conjunction with the ENABLE IFF_OUTPUT command, and the ISOMETRIC, PERSPECTIVE and PROFILE commands.

If the option is selected, a new IFF feature is started whenever the colour of vectors defining a profile changes. The colour is recorded in the IFF file as the feature code (ie. in the first word of the FS entry). This enables the file to be subsequently plotted as a colour image, on a device such as a colour electrostatic plotter.

As with output to a colour graphics device, the form of the isometric or perspective image, is controlled using the COLOUR, ZSTEP, and ZLIMITS commands.

If the option is not selected, it will only be possible to distinguish in the IFF file (using feature code), profiles that are land profiles, profiles outside the height range defined with the ZLIMITS command, or profiles at or below sea-level.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

--------------------------------------------------------------------------------
Messages:

The following error message is specific to the ENABLE command:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE COLOUR_IFF
DTIVIEW>

ENABLE DIVIDE COMMAND

--------------------------------------------------------------------------------
ENABLE DIVIDE

--------------------------------------------------------------------------------

FORMAT:		 ENABLE DIVIDE

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

ENABLE DIVIDE selects the use of quartered screen display mode.

If selected, the graphics screen is divided into 4 quadrants. Each quadrant is treated by the program as though it were a separate graphics screen. This allows 4 different isometric or perspective views to be displayed and compared.

The 4 quadrants are identified as follows:


	1   =	Top lefthand quadrant

	2   =	Top righthand quadrant

	3   =   Bottom righthand quadrant

	4   =   Bottom lefthand quadrant

On selection of a quartered screen, the default quadrant is the top lefthand quadrant. A different quadrant may be selected using the QUADRANT command.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the ENABLE command:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE DIVIDE
DTIVIEW>

ENABLE FISHNET COMMAND

--------------------------------------------------------------------------------
ENABLE FISHNET

--------------------------------------------------------------------------------

FORMAT:		 ENABLE FISHNET

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

ENABLE FISHNET enables the option of producing a fishnet representation of a terrain view when the ISOMETRIC or PERSPECTIVE command is given.

A fishnet representation involves drawing the 3-D terrain view as a grid, rather than as a series of profiles orientated along just one of the DTM axes. Profiles are generated both vertically (south to north) and horizontally (west to east) through the DTM.

A 'fishnet' representation enhances perception when dealing with a sparse data grid (ie. when a small DTM window has been defined), but is less successful when dealing with a dense grid. In the later case it can lead to a poorer perception of the depth relationships in the model, by making the incidental shading effects at the terrain horizons less apparent.

In the current implementation of this option in DTIVIEW, true hidden line removal is only applied to the first set of profiles that are generated. In the case of the second set of profiles drawn to produce the grid representation, only partial hidden line removal is performed to ensure that no vectors completely hidden by previous profiles are shown. The actual intersection of the two sets of profiles with each other is not carried out. The techniques developed to overlay vector data on a 3-D view are used.

By default the option to produce a fishnet representation is not enabled.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the ENABLE command:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE FISHNET
DTIVIEW>

ENABLE FOG COMMAND

--------------------------------------------------------------------------------
ENABLE FOG

--------------------------------------------------------------------------------

FORMAT:		ENABLE FOG

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The ENABLE FOG command is used to enable the visibility restriction option.

The command is also used by the program to activate all DTIVIEW commands that are relevant to the fog option.

The ENABLE FOG command must be given before any of the FOG commands, and before generating a perspective view on which visibility restrictions are to be imposed. The visibility restriction option is only valid for a perspective view and cannot be used when drawing an isometric view.

Note: The visibility restriction option is supplied as a licensed facility; the option may not be available in your version of the program.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating perspective view.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the ENABLE and ENABLE FOG commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE
 
*** ERROR *** Specifying command ENABLE FOG
Fog option cannot be activated

--------------------------------------------------------------------------------
Example:

DTIVIEW>ENABLE FOG
DTIVIEW>

ENABLE GRAPHICS COMMAND

--------------------------------------------------------------------------------
ENABLE GRAPHICS

--------------------------------------------------------------------------------

FORMAT:		 ENABLE GRAPHICS

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

ENABLE GRAPHICS causes output to be directed to a graphics device when the DRAW, ISOMETRIC, PERSPECTIVE, PROFILE or OVERLAY commands are given.

On a workstation that is configured with two graphics devices, both devices will be enabled when the ENABLE GRAPHICS command is given. This is equivalent to giving the commands ENABLE PRIMARY and ENABLE SECONDARY. Output to either device may be selectively disabled using the DISABLE PRIMARY and DISABLE SECONDARY commands.

By default output to a graphics device is not enabled when the program is started.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the ENABLE command:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE GRAPHICS
DTIVIEW>

ENABLE IFF_OUTPUT COMMAND

--------------------------------------------------------------------------------
ENABLE IFF_OUTPUT

--------------------------------------------------------------------------------

FORMAT:		 ENABLE IFF_OUTPUT file-spec

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

ENABLE IFF_OUTPUT directs output to an IFF file when the ISOMETRIC, PERSPECTIVE, PROFILE or OVERLAY commands are given. This enables a terrain view to be subsequently plotted on a device such as a drum plotter, edited in LITES2, or manipulated using IFF utilities.

An IFF file holds a single terrain view, and optionally overlay information. Any overlay data is held in a separate layer to the terrain profiles. The commands SET LAYER, SET LAND_FC, SET NULL_FC and SET SEA_FC may be used to control into which IFF layers the data is written, and which feature codes are assigned to the land and sea profiles.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

--------------------------------------------------------------------------------
Messages:

The following messages are specific to the ENABLE and ENABLE IFF_OUTPUT commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

*** ERROR *** Specifying command ENABLE IFF_OUTPUT
Output IFF filename is missing 

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE IFF_OUTPUT TEST
DTIVIEW>

ENABLE OVERLAY COMMAND

--------------------------------------------------------------------------------
ENABLE OVERLAY

--------------------------------------------------------------------------------

FORMAT:		ENABLE OVERLAY

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The ENABLE OVERLAY command selects the option to overlay vector data derived from an IFF file on an isometric or terrain view. The command is also used by the program to activate all DTIVIEW commands that are relevant to vector overlay, such as the commands IFF, FRT and OVERLAY.

The ENABLE OVERLAY command must be given before any of the vector overlay commands, and before generating the isometric or perspective view on which any data is to be overlaid.

Note. The vector overlay option is supplied as a licensed facility; the option may not be available in your version of the program.

Also note, that in the current implementation of this option in DTIVIEW, overlay of vector data on a 3-D view generated using DTM column and row sample values greater than 1, is not possible.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the ENABLE and ENABLE OVERLAY commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

*** ERROR *** Specifying command ENABLE OVERLAY
Vector overlay option cannot be activated

*** ERROR *** Specifying command ENABLE OVERLAY
Overlay options are currently only available 
with a column and row sampling interval of 1
Overlay options are not enabled

--------------------------------------------------------------------------------
Example:

DTIVIEW>ENABLE OVERLAY
DTIVIEW>

ENABLE PICTURE COMMAND

--------------------------------------------------------------------------------
ENABLE PICTURE

--------------------------------------------------------------------------------

FORMAT:		 ENABLE PICTURE picture_number

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The ENABLE PICTURE command is used to select (make visible) the bit-planes of a graphics device that are currently allocated to the specified picture.

The number of bit-planes allocated to picture 1 and picture 2 is determined using the PLANES command.

An isometric or perspective terrain view is drawn into Picture 1, while any vector overlay information or annotation drawn using the OVERLAY and DRAW LABEL commands, is displayed in Picture 2. Giving the command ENABLE PICTURE 2 will therefore make visible any vector overlay or annotation, that may have been made deselected (made invisible) using the DISABLE PICTURE 2 command.

Note that this command is not applicable if the output graphics device is a TEKTRONIX 4014, or if the device is configured with only 4 bit-planes.

The SHOW ENABLE command may be used to check on the status of the 2 pictures.

--------------------------------------------------------------------------------
Messages:

The following error message is specific to the ENABLE and ENABLE PICTURE command:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

*** ERROR *** Specifying command ENABLE PICTURE
Command requires an integer argument

*** ERROR *** Specifying command ENABLE PICTURE
Command requires a picture number of 1 or 2

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE PICTURE 2
DTIVIEW>

ENABLE PRIMARY COMMAND

--------------------------------------------------------------------------------
ENABLE PRIMARY

--------------------------------------------------------------------------------

FORMAT:		 ENABLE PRIMARY

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

ENABLE PRIMARY causes output to be directed to the primary workstation graphics device when a DRAW, ISOMETRIC, PERSPECTIVE, PROFILE or OVERLAY command is given.

The command is only useful when DTIVIEW is being run on a workstation that is configured with two graphics devices. Typically such a workstation will consist of a monochrome and colour display; the monochrome display is the primary device, and the colour display is the secondary device.

On a workstation configured with a single display, the display is the primary device. In this situation use of the commands ENABLE GRAPHICS and DISABLE GRAPHICS to select and deselect output to the device is to be preferred.

By default output to the primary device is selected when the ENABLE GRAPHICS command is given.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the ENABLE and ENABLE PRIMARY commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

*** ERROR *** Specifying command ENABLE PRIMARY
A PRIMARY graphics device is not supported

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE PRIMARY
DTIVIEW>

ENABLE SECONDARY COMMAND

--------------------------------------------------------------------------------
ENABLE SECONDARY

--------------------------------------------------------------------------------

FORMAT:		 ENABLE SECONDARY

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

ENABLE SECONDARY causes output to be directed to the secondary workstation graphics device when a DRAW, ISOMETRIC, PERSPECTIVE, PROFILE or OVERLAY command is given.

The command is only useful when DTIVIEW is being run on a workstation that is configured with two graphics devices. Typically such a workstation will consist of a monochrome and colour display; the monochrome display is the primary device, and the colour display is the secondary device.

On a workstation configured with a single display, no secondary graphics device will exist, and the command ENABLE SECONDARY will have no effect.

By default output to any secondary device is selected when the ENABLE GRAPHICS command is given.

Use of the SHOW ENABLE command is recommended to check on the status of the option before a terrain view is generated.

--------------------------------------------------------------------------------
Messages:

The following messages are specific to the ENABLE and ENABLE SECONDARY commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE

*** ERROR *** Specifying command ENABLE SECONDARY
A SECONDARY graphics device is not supported

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ENABLE SECONDARY
DTIVIEW>

ENABLE SYMBOLS COMMAND

--------------------------------------------------------------------------------
ENABLE SYMBOLS

--------------------------------------------------------------------------------

FORMAT:		ENABLE SYMBOLS

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The ENABLE SYMBOLS command selects the option that allows symbols to be interactively drawn on an isometric or perspective terrain view. The command is also used by the program to activate all DTIVIEW commands that are relevant to symbol plotting, such as the commands FRT and SYMBOL FC.

The ENABLE SYMBOLS command must be given before any of the symbol commands, and before generating the isometric or perspective view on which any symbols are to be drawn.

Note. The symbol plotting option is supplied as a licensed facility; the option may not be available in your version of the program.

Use of the SHOW ENABLE command is recommended to check on the status of the option before generating an isometric or perspective view.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the ENABLE and ENABLE SYMBOLS commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE
 
*** ERROR *** Specifying command ENABLE SYMBOLS
Symbol plotting option cannot be activated


--------------------------------------------------------------------------------
Example:

DTIVIEW>ENABLE SYMBOLS
DTIVIEW>

ENABLE TABLE COMMAND

--------------------------------------------------------------------------------
ENABLE TABLE

--------------------------------------------------------------------------------

FORMAT:		ENABLE TABLE

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The ENABLE TABLE command initialises the table monitor to allow input from a digitising table. The command SETUP MAP may be used to register a map to the DTI file, while SETUP MENU allows commands to be input using the DTIVIEW menu. In the event of failure, input from the digitising table or puck button is not possible, and the program will accept commands only from the terminal.

Table initialisation will generally fail because no Table Monitor is currently active, or because the Table Monitor is locked by another user. If neither of these reasons appear to apply, you should consult the TABLIB Reference Manual, or seek guidance from your system manager.

If the logical name LSL$AUTO_ENABLE_TABLE is defined with a value of "1", then the table is initialised on program startup.

The DISABLE TABLE command may be used to turn off input from the digitising table.

The SHOW ENABLE command may be used to check on the status of table input.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the ENABLE and ENABLE TABLE commands:


*** ERROR *** Specifying command ENABLE
Command qualifiers are ABSOLUTE, AUTOSCALE, BATHYMETRY, COLOUR_IFF, DIVIDE 
		       FISHNET,FOG, GRAPHICS, IFF_OUTPUT, OVERLAY, PICTURE
		       PRIMARY, SECONDARY, SYMBOLS or TABLE
 
*** WARNING *** Initialising table monitor
DTIVIEW will assume no table is available



--------------------------------------------------------------------------------
Example:

DTIVIEW>ENABLE TABLE
DTIVIEW>

EXIT COMMAND

--------------------------------------------------------------------------------
EXIT

--------------------------------------------------------------------------------

FORMAT:		 EXIT

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

The EXIT command is used to exit from DTIVIEW.
(pressing the Ctrl and Z keys together) may also be used to exit from the program.

--------------------------------------------------------------------------------
Messages: None.

--------------------------------------------------------------------------------
Examples:

DTIVIEW>EXIT
$

FILEIN COMMAND

--------------------------------------------------------------------------------
FILEIN

--------------------------------------------------------------------------------

FORMAT:		 FILEIN file-spec

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

This command opens and maps into memory a DTI file, containing the terrain elevation data that will be used when generating an isometric or perspective view.
Details derived from the header of the file are displayed on the terminal to confirm that the file has been successfully opened.
If the logical name LSL$MATRIX_DEFAULT_WINDOW is defined with a value of "1", then a default area of interest defined in matrix units of bottom left hand corner 1,1 and top right hand corner 200,200 is set when the file is opened. If the logical name is absent or has any other value, or if the input DTI file has fewer than 200 columns or 200 rows, then a default window equivalent to the total matrix is set.

--------------------------------------------------------------------------------
Messages:

The following error message is specific to the FILEIN command:


*** ERROR *** Specifying command FILEIN
Input DTI filename is missing

--------------------------------------------------------------------------------
Example:

DTIVIEW>FILEIN TEST


LSL$DTI:TEST.DTI	
Header: MIKE	 Data: WORD

Units are DTI Matrix Values

Matrix Coverage    SW:    1     1    NE:   301   251
Matrix Window      SW:    1     1    NE:   200   200
Matrix Interval	    E:	  1	      N:     1
Value Range	     :      0   to    851


DTIVIEW>

FOG COLOUR COMMAND

--------------------------------------------------------------------------------
FOG COLOUR

--------------------------------------------------------------------------------

FORMAT:		FOG COLOUR index

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The FOG COLOUR command is used to set the fog colour, ie. the colour index used to draw all areas of the perspective view that lie beyond the current limit of visibility. By default the colour index is 0 (ie. black) so that areas in fog will not be visible on the screen.

Setting the fog colour to a value other than black will allow a false colour to be assigned to all DTM nodes beyond the visibility distance irrespective of height of the node. The fog colour has no effect on culture or symbol data which are always plotted in black beyond the visibility distance. Culture and symbol data are therefore always invisible to the observer if within the fog.

The FOG COLOUR command must be given prior to generating a perspective view.

The command is only valid if the ENABLE FOG command has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the FOG and FOG COLOUR commands:


*** ERROR *** Specifying command FOG
Fog has not been enabled

*** ERROR *** Specifying command FOG
Command qualifiers are COLOUR or VISIBILITY

*** ERROR *** Specifying command FOG COLOUR
Command requires integer colour index in the range 0 to 

--------------------------------------------------------------------------------
Examples:

DTIVIEW>FOG COLOUR 1<CR>
DTIVIEW>

FOG VISIBILITY COMMAND

--------------------------------------------------------------------------------
FOG VISIBILITY

--------------------------------------------------------------------------------

FORMAT:		FOG VISIBILITY distance

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The FOG VISIBILITY command is used to define the limit of visibility. By default the visibility distance is set to 1000.0 metres.

All terrain DTM nodes, culture and symbols that lie within the visibility distance are displayed without being affected by the fog. Terrain DTM nodes that lie beyond the limit of visibility are considered to lie within an area of fog, and are drawn in the current fog colour index. The fog colour is defined using the FOG COLOUR command, but by default is black. Culture and symbol data lying beyond the visibility distance will be considered to be in the fog and will not be plotted.

The command is only valid if the ENABLE FOG command has been previously given, and should be given prior to generating a perspective view.

The SHOW VIEW command may be used to examine the current fog visibility distance value.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the FOG and FOG VISIBILITY commands:


*** ERROR *** Specifying command FOG
Fog has not been enabled

*** ERROR *** Specifying command FOG
Command qualifiers are COLOUR or VISIBILITY

*** ERROR *** Specifying command FOG VISIBILITY
Command requires one real argument greater than 0.0

--------------------------------------------------------------------------------
Examples:

DTIVIEW>FOG VISIBILITY 1500<CR>
DTIVIEW>

FRT COMMAND

--------------------------------------------------------------------------------
FRT

--------------------------------------------------------------------------------

FORMAT:	        FRT  file-spec

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

This command reads the specified Feature Representation Table.
It is only appropriate to the overlay of vector data and the plotting of symbol data on a terrain view.

For overlays the entries in the FRT are used to determine the graphical representation of IFF features. DTIVIEW uses the table to determine the graphical type and colour representation of any IFF features that are overlaid on the terrain view. The table also defines feature code group names that may be supplied as parameters to the SELECT FC or DESELECT FC commands.

For symbols the entries in the FRT are use to determine which entry in the SRI file to use.

A FRT must be defined before the OVERLAY command or the SYMBOL command is given.

The command is only valid if the ENABLE OVERLAY or the ENABLE SYMBOLS has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error message is specific to the FRT command:


*** ERROR *** Specifying command FRT
Overlay options are not enabled

*** ERROR *** Specifying command FRT
Input FRT filename is missing

--------------------------------------------------------------------------------
Examples:

DTIVIEW>FRT DTIVIEW.FRT
DTIVIEW>

HEIGHT COMMAND

--------------------------------------------------------------------------------
HEIGHT

--------------------------------------------------------------------------------

FORMAT:		 HEIGHT height_of_view

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

HEIGHT defines the height of the view point. The parameter is specified as a height above sea level in metres.

The parameter is used when generating a perspective view.

By default a height value of 300.0 is used.

Use of the SHOW VIEW command is recommended to check on the status of the parameter before a perspective view is generated.

Note: The height value is multiplied by the current vertical exaggeration (zscale) value.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the HEIGHT command:


*** ERROR *** Specifying command HEIGHT
Command requires 1 real argument

--------------------------------------------------------------------------------
Examples:

DTIVIEW>HEIGHT 100.5
DTIVIEW>

HELP COMMAND

--------------------------------------------------------------------------------
HELP

--------------------------------------------------------------------------------

FORMAT:		 HELP [command]

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

A brief description is given of the function and format of the specified command.
If no parameter is supplied then a list of all commands available is given.

--------------------------------------------------------------------------------
Messages: None.

--------------------------------------------------------------------------------
Examples:

DTIVIEW>HELP DISTANCE
DTIVIEW>

IFF COMMAND

--------------------------------------------------------------------------------
IFF

--------------------------------------------------------------------------------

FORMAT:	        IFF  file-spec

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The IFF command specifies the name of an Internal Feature Format file, containing vector data that is to overlaid on a terrain view.

A default area of interest within the IFF file is set when the file is opened. This may be subsequently altered using the IFFWINDOW command. If origin offset values are present in the headers of the DTI and IFF files, then the IFF window is set with respect to the current DTI window. This allows registration between the terrain view and the vector overlay to take place automatically. If no such header information is present, or if the DISABLE ABSOLUTE command has been given, then the default area of interest in the IFF file that corresponds to the IFF range entry (RA) values is set.

The IFF file range and IFF window may be examined using the command SHOW IFF.

The command is only valid if the ENABLE OVERLAY command has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the IFF command:


*** ERROR *** Specifying command IFF
Overlay options are not enabled

*** ERROR *** Specifying command IFF
Input IFF filename is missing

--------------------------------------------------------------------------------
Examples:

DTIVIEW>IFF TEST
DTIVIEW>

IFFWINDOW COMMAND

--------------------------------------------------------------------------------
IFFWINDOW

--------------------------------------------------------------------------------

FORMAT:	        IFFWINDOW swx swy nex ney

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

IFFWINDOW is used to define a rectangular area of interest within the IFF file. By default or if the ENABLE ABSOLUTE command has been given then window values should be supplied in absolute IFF units. Otherwise values should be specified as an offset from the SW corner of the IFF file area.

The IFFWINDOW command enables the IFF file to be registered to the current area of interest in the DTM.
When the command is given, a transformation matrix for IFF to DTM coordinate conversion is calculated, based on the coordinates of the IFF and DTM windows.

The command SHOW IFF may be used to examine the IFF range and window coordinate values.

The command is only valid if the ENABLE OVERLAY and IFF commands have been previously given

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the IFFWINDOW command:


*** ERROR *** Specifying command IFFWINDOW
Overlay options are not enabled

*** ERROR *** Specifying command IFFWINDOW
No input IFF has been specified

*** ERROR *** Specifying command IFFWINDOW
Command requires 4 real arguments

*** ERROR *** Specifying command IFFWINDOW
NE corner should exceed SW corner

*** WARNING *** Specified window outside IFF file coordinate range

--------------------------------------------------------------------------------
Examples:

DTIVIEW>IFFWINDOW 310000.0 220000.0 270000.0 180000.0
DTIVIEW>

ISOMETRIC COMMAND

--------------------------------------------------------------------------------
ISOMETRIC

--------------------------------------------------------------------------------

FORMAT:		 ISOMETRIC

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The command ISOMETRIC is given to generate an isometric terrain view.

The view is generated using the current viewing direction and vertical exaggeration parameters, and using the current phi and theta rotation values.

Only DTM nodes lying within the current DTM area of interest are used when generating the isometric view.

The isometric view may either be output to a graphics device, or the plot coordinates may be sent to an IFF file for subsequent plotting or manipulation.
Output is controlled by the ENABLE GRAPHICS and ENABLE IFF_OUTPUT commands.

Typing (Pressing the Ctrl and C keys together) will abort the generation of the isometric view, and return the user to the DTIVIEW> prompt.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the ISOMETRIC command:


*** ERROR *** Specifying command ISOMETRIC
The input DTM is undefined

*** ERROR *** Specifying command ISOMETRIC
No graphics device or output IFF file is enabled

--------------------------------------------------------------------------------
Examples:

DTIVIEW>ISOMETRIC
DTIVIEW>

LABEL CLEAR COMMAND

--------------------------------------------------------------------------------
LABEL CLEAR

--------------------------------------------------------------------------------

FORMAT:		LABEL CLEAR

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The command causes all annotation that has been generated on a graphics screen using the DRAW LABEL command to be erased.

On a graphics device with more than 4 planes, the labels are written to the bit-planes allocated to PICTURE 2. Giving the command CLEAR PICTURE 2 therefore has the same effect as the command DRAW LABEL. Both commands will cause any vector overlay generated using the OVERLAY command, to be also cleared.

Annotation output to a Tektronix 4014 display or to a graphics device configured with 4 bit-planes, cannot be selectively erased using this command.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the LABEL and LABEL CLEAR commands:


*** ERROR *** Specifying command LABEL
Command qualifiers are CLEAR, COLOUR, POSITION, or SIZE

*** ERROR *** Specifying command LABEL CLEAR
No graphics device is currently enabled

*** ERROR *** Specifying command LABEL CLEAR
Command is not valid for a 4 planes graphics device

--------------------------------------------------------------------------------
Example:

DTIVIEW>LABEL CLEAR
DTIVIEW>

LABEL COLOUR COMMAND

--------------------------------------------------------------------------------
LABEL COLOUR

--------------------------------------------------------------------------------

FORMAT:		LABEL COLOUR index

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The command LABEL COLOUR determines which colour will be used to write a label when the DRAW LABEL command is given.

The number of colours available for labelling is the same as for overlay, and is dependent on the current planes setting defined using the PLANES command. By default DTIVIEW allocates 5 planes to the terrain view, and 3 planes to any annotation or overlay, and uses the colour table DTIVIEW5.DAT 7 different label colours have been defined in this table. The number of overlay colours available at any time, may be examined using the SHOW DEVICE command.

By default labels are drawn in colour 1.

--------------------------------------------------------------------------------
Messages:

The following error message are specific to the LABEL and LABEL COLOUR command:


*** ERROR *** Specifying command LABEL
Command qualifiers are CLEAR, COLOUR, POSITION, or SIZE

*** ERROR *** Specifying command LABEL COLOUR
Command requires 1 integer argument

*** ERROR *** Specifying command LABEL COLOUR
Command requires an integer in the range 1 to 

*** ERROR *** Specifying command LABEL COLOUR
Command is not valid for a 4 planes graphics device

--------------------------------------------------------------------------------
Examples:

DTIVIEW>LABEL COLOUR 3
DTIVIEW>

LABEL POSITION COMMAND

--------------------------------------------------------------------------------
LABEL POSITION

--------------------------------------------------------------------------------

FORMAT:		LABEL POSITION screen_x screen_y

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

LABEL POSITION defines the position of a label on the screen.

The values are specified in normalised device coordinates. For example, coordinates of 0.5 0.5 will write a text string with the first character positioned in the centre of the screen.

--------------------------------------------------------------------------------
Messages:

The following error message are specific to the LABEL and LABEL POSITION command:


*** ERROR *** Specifying command LABEL
Command qualifiers are CLEAR, COLOUR, POSITION, or SIZE

*** ERROR *** Specifying command LABEL POSITION
Command requires 2 real arguments

*** ERROR *** Specifying command LABEL POSITION
Command requires 2 real arguments in the range 0 to 1

--------------------------------------------------------------------------------
Examples:

DTIVIEW>LABEL POSITION 0.3 0.54
DTIVIEW>

LABEL SIZE COMMAND

--------------------------------------------------------------------------------
LABEL SIZE

--------------------------------------------------------------------------------

FORMAT:		LABEL SIZE character_size

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The command LABEL SIZE is used to define the size of any text output to a graphics screen using the DRAW LABEL command.

The character_size parameter controls the relative size of the text; size 1 is the smallest, and size 4 is the largest. The actual size of the text output to the screen will vary with the size of the graphics device screen, however the relative sizes of the text will remain constant.

By default, a label is output in size 1.

--------------------------------------------------------------------------------
Messages:

The following error message are specific to the LABEL and LABEL SIZE commands:


*** ERROR *** Specifying command LABEL
Command qualifiers are CLEAR, COLOUR, POSITION, or SIZE

*** ERROR *** Specifying command LABEL SIZE
Command requires 1 integer argument

*** ERROR *** Specifying command LABEL SIZE
Command requires an integer argument in the range 1 to 4

--------------------------------------------------------------------------------
Examples:

DTIVIEW>LABEL SIZE 3
DTIVIEW>

LEGEND POSITION COMMAND

--------------------------------------------------------------------------------
LEGEND POSITION

--------------------------------------------------------------------------------

FORMAT:		LEGEND POSITION screen_x screen_y

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The LEGEND POSITION command is used to control where the legend is drawn on a graphics screen when the DRAW LEGEND command is given.
The supplied coordinates define the position of the bottom left hand corner of the first legend box.

By default the legend is positioned below and to the left of a terrain view at position (in NDC) x 0.005 and y 0.15.

It is often useful to vary the legend position so that it does not interfere with the terrain view.

--------------------------------------------------------------------------------
Messages:

The following error message are specific to the LEGEND and LEGEND POSITION commands:


*** ERROR *** Specifying command LEGEND
Command qualifiers are POSITION or SIZE

*** ERROR *** Specifying command LEGEND POSITION
Command requires 2 real arguments

*** ERROR *** Specifying command LEGEND POSITION
Command requires real arguments in the range 0 to 1

--------------------------------------------------------------------------------
Examples:

DTIVIEW>LEGEND POSITION 0.2 0.5
DTIVIEW>

LEGEND SIZE COMMAND

--------------------------------------------------------------------------------
LEGEND SIZE

--------------------------------------------------------------------------------

FORMAT:		LEGEND SIZE scale_factor

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The LEGEND SIZE command is used to control the size of the legend on the screen when the DRAW LEGEND command is given.

By default the legend is drawn with a scale factor of 0.25

--------------------------------------------------------------------------------
Messages:

The following error message are specific to the LEGEND and LEGEND SIZE commands:


*** ERROR *** Specifying command LEGEND
Command qualifiers are POSITION or SIZE

*** ERROR *** Specifying command LEGEND SIZE
Command requires 1 real argument

*** ERROR *** Specifying command LEGEND SIZE
Command requires a real argument in the range 0 to 1

--------------------------------------------------------------------------------
Examples:

DTIVIEW>LEGEND SIZE 0.4
DTIVIEW>

LUT COMMAND

--------------------------------------------------------------------------------
LUT

--------------------------------------------------------------------------------

FORMAT:	        LUT  file-spec

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

This command is used to select a colour table. The colour table is a file containing the RGB definitions for a series of colour values. These colour values are used when drawing an isometric or perspective view on a colour graphics device.

The default colour table which is read when a graphics device is first enabled is dependent on the current planes setting. By default DTIVIEW allocates 5 planes to PICTURE 1, and therefore the colour table DTIVIEW5.DAT is read. Using the LUT command, an alternative colour table may be subsequently used.

If a terrain view has already been output to a graphics device, the effect of reading a new colour table using the LUT command is immediately seen.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the LUT command command:


*** ERROR *** Specifying command LUT
No graphics device is currently enabled

*** ERROR *** Specifying command LUT
Command not valid for a TEKTRONIX 4014

*** ERROR *** Specifying command LUT
Unable to read specified colour table

--------------------------------------------------------------------------------
Examples:

DTIVIEW>LUT MYTABLE
DTIVIEW>

OVERLAY COMMAND

--------------------------------------------------------------------------------
OVERLAY

--------------------------------------------------------------------------------

FORMAT:		 OVERLAY

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The command OVERLAY is used to overlay vector features from an IFF file on to an isometric or perspective terrain view.

With a planes setting of 5 6 or 7, the vector data is drawn into picture 2; with a planes setting of 4, the data is drawn into picture 1. No overlay is possible if 8 planes have been allocated to picture 1.

The SELECT and DESELECT commands control which IFF features are selected for overlay. A FRT is used to define the graphical type of the feature (symbol, line or area), and to determine the colour in which the feature will be drawn. A SRI file is used to determine the representation of symbols.

Automatic registration of the vector data to the DTM takes place if both DTI and IFF files contain origin offset values in the file headers. Registration may be controlled explicitly using the commands IFFWINDOW and WINDOW.
Output is controlled by the ENABLE GRAPHICS and ENABLE IFF_OUTPUT commands.

The OVERLAY command is only valid if the ENABLE OVERLAY has been given prior to generating the isometric or perspective view on which data is to be overlaid. An IFF and FRT file, and optionally a SRI file, must have been previously defined.

Typing (Pressing the Ctrl and C keys together) causes the current OVERLAY operation to be aborted, and will return the user to the DTIVIEW> prompt.

Further details on the vector overlay facilities are to be find in the description section of the introduction.

--------------------------------------------------------------------------------
Messages: The following messages are specific to the OVERLAY command.


*** ERROR *** Specifying command OVERLAY
Overlay options are not enabled

*** ERROR *** Specifying command OVERLAY
No IFF file has been specified

*** ERROR *** Specifying command OVERLAY
No FRT file has been specified

*** ERROR *** Specifying command OVERLAY
Before overlay it is necessary to generate a terrain view
Use the command ISOMETRIC or PERSPECTIVE

*** ERROR *** Specifying command OVERLAY
Overlay not possible with a planes selection of 8

--------------------------------------------------------------------------------
Examples:

DTIVIEW>OVERLAY
DTIVIEW>

PERSPECTIVE COMMAND

--------------------------------------------------------------------------------
PERSPECTIVE

--------------------------------------------------------------------------------

FORMAT:		 PERSPECTIVE

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

The command PERSPECTIVE is given to generate a perspective terrain view.

The view is generated using the current viewing direction, distance, height and vertical exaggeration parameters, and using the current phi rotation value. These values may be examined using the SHOW VIEW command.

Only DTM nodes lying within the current DTM area of interest are used when generating the perspective view.

The perspective view may either be output to a graphics device, or the plot coordinates may be sent to an IFF file for subsequent plotting or manipulation.
Output is controlled by the ENABLE GRAPHICS and ENABLE IFF_OUTPUT commands.

Typing (Pressing the Ctrl and C keys together) will abort the generation of the perspective view, and return the user to the DTIVIEW> prompt.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the PERSPECTIVE command:


*** ERROR *** Specifying command PERSPECTIVE
The input DTM is undefined

*** ERROR *** Specifying command PERSPECTIVE
No graphics device or output IFF file is enabled

--------------------------------------------------------------------------------
Examples:

DTIVIEW>PERSPECTIVE
DTIVIEW>

PHI COMMAND

--------------------------------------------------------------------------------
PHI

--------------------------------------------------------------------------------

FORMAT:		 PHI  rotation

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The command PHI defines the degree of rotation in the x axis that is applied to an isometric or perspective terrain view.

Applying a rotation in the x axis can be a valuable aid to interpreting a 3 dimensional view. Most frequently a rotation of 45 degrees is applied, so that a corner of the terrain view is pointing towards the viewer.

If an angle greater than 80 degrees is required for a particular direction, use a different direction and a small value for PHI.

By default a rotation of 45 degrees is applied to all terrain views.

Use of the SHOW VIEW command is recommended to check on the x rotation value before a terrain view is generated.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the PHI command:


*** ERROR *** Specifying command PHI
Command requires 1 real argument

*** ERROR *** Specifying command PHI
Command requires a rotation value in the range -80 to 80 degrees

--------------------------------------------------------------------------------
Examples:

DTIVIEW>PHI 30.0
DTIVIEW>

PLANES COMMAND

--------------------------------------------------------------------------------
PLANES

--------------------------------------------------------------------------------

FORMAT:		 PLANES	 number_planes

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

PLANES defines the number of bit-planes on a graphics device that will be allocated to PICTURE 1. It therefore determines the maximum number of colours that are available for display of a terrain view.

By default a set of 5 planes are allocated to PICTURE 1. This allows 32 colours to be defined, although in practice a maximum of 29 colours will be used when drawing the terrain surface, since the first 3 colours have a special use.

The remaining planes on an 8 bit-plane graphics device are allocated to picture 2, and used for the display of any vector overlay drawn using the OVERLAY command, and for any annotation generated using the DRAW LABEL command. With a planes setting of 5, 7 overlay and annotation colours are available. The LABEL COLOUR command may be used to select the annotation colour, while the colour entry in the FRT determines in what colour, different overlay features are shown.

It should be noted that after giving the PLANES command, a default colour table appropriate to the number of planes, is read. The effect of this will either be seen immediately if a terrain view is already displayed, or on the initialisation of the graphics device.

The command PLANES 4 should be given if you are using a graphics device configured with 4 bit-planes. This command will ensure that the terrain view, and any vector overlay and annotation, will use the same set of planes. It also ensures that commands not relevant to a 4 planes graphics device are not acted upon.

Further information on the default colour tables, and the use of the PLANES command may be found in the introductory description section.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the PLANES command:


*** ERROR *** Specifying command PLANES
Command requires 1 integer argument

*** ERROR *** Specifying command PLANES
Command requires an integer in the range 4 to 8

--------------------------------------------------------------------------------
Examples:

DTIVIEW>PLANES 6
DTIVIEW>

PROFILE COMMAND

--------------------------------------------------------------------------------
PROFILE

--------------------------------------------------------------------------------

FORMAT:	        PROFILE  x_start y_start x_end y_end

--------------------------------------------------------------------------------
Command parameters:

The format of the command parameters is controlled by the UNITS command.

Note that in all cases, the input values are adjusted to the nearest column and row values.

If the command is issued via the table menu, or if the command PROFILE without any arguments is given, you will be asked to supply a start and end value in response to appropriate prompts.

--------------------------------------------------------------------------------
DESCRIPTION:

The command PROFILE is given to generate a simple cross section between two DTM node points.

The current vertical exaggeration value is applied to the cross section.

The profile may be output to a graphics device, or may be sent to an IFF file for subsequent plotting or manipulation.
Output is controlled by the ENABLE GRAPHICS and ENABLE IFF_OUTPUT commands.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the PROFILE command:


*** ERROR *** Specifying command PROFILE
The input DTM is undefined

*** ERROR *** Specifying command PROFILE
No graphics device or output IFF file is enabled

*** ERROR *** Specifying command PROFILE
Command requires 4 coordinate arguments

*** ERROR *** Specifying command PROFILE
Coordinate values must lie within DTM limits

--------------------------------------------------------------------------------
Examples:

DTIVIEW>UNITS MATRIX
DTIVIEW>PROFILE 10 10 15 33
DTIVIEW>

QUADRANT COMMAND

--------------------------------------------------------------------------------
QUADRANT

--------------------------------------------------------------------------------

FORMAT:		 QUADRANT quadrant_number

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The QUADRANT command controls which quadrant of a divided graphics screen will be used for the display of an isometric or perspective terrain view.

The command is only valid if use of a quartered screen has been selected using the ENABLE DIVIDE command.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the QUADRANT command:


*** ERROR *** Specifying command QUADRANT
Command requires 1 integer argument

*** ERROR *** Specifying command QUADRANT
Command requires an integer argument in the range 1 to 4

*** ERROR *** Specifying command QUADRANT
Divided screen is not enabled

--------------------------------------------------------------------------------
Examples:

DTIVIEW>QUADRANT 4
DTIVIEW>

SAMPLE COMMAND

--------------------------------------------------------------------------------
SAMPLE

--------------------------------------------------------------------------------

FORMAT:	        SAMPLE column_interval row_interval

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

SAMPLE is used to define the interval at which DTIVIEW samples the columns and rows of the DTM.

By default all nodes in the DTM area of interest are used to generate the 3-D terrain view (ie. a sample interval of 1 along both the columns and rows).

The SAMPLE command is useful when generating a terrain view covering a large area of interest. A quick look view may be generated first by sampling along the columns and rows, and subsequently a full view without sub-sampling. The command SAMPLE 1 1 should be used to specify that no sub-sampling is applied, if a previous SAMPLE command has redefined the sample intervals.

Note that irrespective of the sample intervals, the last column or row (depending on the viewing direction), in the DTM area of interest is always shown on the 3-D terrain view.

Note that in the current implementation of DTIVIEW, IFF features may only be overlaid on a terrain view generated with column and row sampling intervals of 1.

--------------------------------------------------------------------------------
Message:

The following error messages are specific to the SAMPLE command:


*** ERROR *** Specifying command SAMPLE
Command requires 2 integer arguments

*** ERROR *** Specifying command SAMPLE
Command requires 2 positive integer arguments

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SAMPLE 2 2
DTIVIEW>

SELECT ALL COMMAND

--------------------------------------------------------------------------------
SELECT ALL

--------------------------------------------------------------------------------

FORMAT:	        SELECT ALL

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

SELECT ALL resets all IFF feature selections made using any of the SELECT or DESELECT commands.

The SELECT ALL command is only valid if the ENABLE OVERLAY command has been previously given.

--------------------------------------------------------------------------------
Message:

The following error messages are specific to the SELECT command:


*** ERROR *** Specifying command SELECT
Command qualifiers are ALL, FC, FSN or LAYER

*** ERROR *** Specifying command SELECT
Overlay options are not enabled

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SELECT ALL
DTIVIEW>SELECT FSN 7-10,56-78
DTIVIEW>SHOW SELECTIONS



DTIVIEW>SELECT ALL
DTIVIEW>SHOW SELECTIONS


DTIVIEW>

SELECT FC COMMAND

--------------------------------------------------------------------------------
SELECT FC

--------------------------------------------------------------------------------

FORMAT:         SELECT FC feature_code [,...]

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SELECT FC command is used to include an IFF feature for overlay on an isometric or perspective view. Features are included on the basis of their feature code.

By default DTIVIEW will use all features within an IFF file.

Use of the SHOW SELECTIONS command is recommended to check on feature selections before the OVERLAY command is given.

The SELECT FC command is only valid if the ENABLE OVERLAY command has been previously given, and the FRT command has been used to specify a Feature Representation Table.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SELECT command:


*** ERROR *** Specifying command SELECT
Command qualifiers are ALL, FC, FSN, or LAYER             

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SELECT FC 1
DTIVIEW>SELECT FC RAILWAYS
DTIVIEW>SELECT FC RIVERS 7-10,56-78
DTIVIEW>

SELECT FSN COMMAND

--------------------------------------------------------------------------------
SELECT FSN

--------------------------------------------------------------------------------

FORMAT:	        SELECT FSN fsn [,...]

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SELECT FSN command is used to include IFF features for overlay on an isometric or perspective view. Features are included on the basis of their feature serial number.

By default DTIVIEW will use all features within an IFF file.

Use of the SHOW SELECTIONS command is recommended to display feature selections before the OVERLAY command is given.

The SELECT FSN command is only valid if the ENABLE OVERLAY command has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SELECT command:


*** ERROR *** Specifying command SELECT
Command qualifiers are ALL, FC, FSN, or LAYER             

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SELECT FSN 4
DTIVIEW>SELECT FSN 7-10,56-78
DTIVIEW>

SELECT LAYER COMMAND

--------------------------------------------------------------------------------
SELECT LAYER

--------------------------------------------------------------------------------

FORMAT:	        SELECT LAYER layer [,...]

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SELECT LAYER command is used to include IFF features for overlay on an isometric or perspective view. Features are included on the basis of IFF layer.

By default DTIVIEW will use all features within an IFF file.

Use of the SHOW SELECTIONS command is recommended to display feature selections before the OVERLAY command is given.

The SELECT LAYER command is only valid if the ENABLE OVERLAY command has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SELECT command:


*** ERROR *** Specifying command SELECT
Command qualifiers are ALL, FC, FSN, or LAYER             

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SELECT LAYER 7
DTIVIEW>SELECT LAYER 1,7-10
DTIVIEW>

SET DEFAULT ANNOTATION COMMAND

--------------------------------------------------------------------------------
SET DEFAULT ANNOTATION*

--------------------------------------------------------------------------------

FORMAT:		 SET DEFAULT ANNOTATION

--------------------------------------------------------------------------------
Command parameters:
_None

--------------------------------------------------------------------------------
DESCRIPTION:

This command is used to set all LABEL (colour, size and position) and LEGEND ( size and position ) parameters to their default values.

The default annotation values may be examined using the command SHOW ANNOTATION after giving the SET DEFAULT ANNOTATION command.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET DEFAULT commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC or SYMBOL_SCALE

*** ERROR *** Specifying command SET
Command qualifiers are ANNOTATION or VIEW

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET DEFAULT ANNOTATION
DTIVIEW>

SET DEFAULT VIEW COMMAND

--------------------------------------------------------------------------------
SET DEFAULT VIEW

--------------------------------------------------------------------------------

FORMAT:		 SET DEFAULT VIEW

--------------------------------------------------------------------------------
Command parameters: _None

--------------------------------------------------------------------------------
DESCRIPTION:

This command is used to set all viewing parameters to their default values.

The default viewing values may be examined using the command SHOW VIEW after giving the SET DEFAULT VIEW command.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET DEFAULT commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC or SYMBOL_SCALE

*** ERROR *** Specifying command SET
Command qualifiers are ANNOTATION or VIEW

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET DEFAULT VIEW
DTIVIEW>

SET LAND_FC COMMAND

--------------------------------------------------------------------------------
SET LAND_FC

--------------------------------------------------------------------------------

FORMAT:		 SET LAND_FC feature_code

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET LAND_FC command is used to specify the code given to features in the IFF output file that are profiles across the land surface.

By default such features are given a code of 1, and features that define a line across the sea surface are given a code of 2. This allows the IFF data to be plotted, so that the land and sea may be distinguished in different colours or line styles.

The command SET SEA_FC should be used to set the feature code of profiles across the sea surface.

The command is only relevant when using the ENABLE IFF_OUTPUT option, to write a terrain view to an IFF file.

Use of the SHOW SETTINGS command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET LAND_FC commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET LAND_FC
Command requires 1 integer argument

*** ERROR *** Specifying command SET LAND_FC
Command requires a feature code in the range 1 to 32767

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET LAND_FC 5
DTIVIEW>

SET LAYER COMMAND

--------------------------------------------------------------------------------
SET LAYER

--------------------------------------------------------------------------------

FORMAT:		 SET LAYER layer

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET LAYER command is used to specify the layer into which features are placed in the IFF output file.

Once a layer has been created in the output IFF file, the layer number is automatically incremented by 1. This ensures that any overlay data also output to the file, is held in a separate layer to the terrain profiles.

By default features are written to layer 1 in the IFF file.

The command is only relevant when using the ENABLE IFF_OUTPUT option, to write a terrain view to an IFF file.

Use of the SHOW SETTINGS command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET LAYER commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET LAYER
Command requires 1 integer argument

*** ERROR *** Specifying command SET LAYER
Command requires a feature code in the range 1 to 32767

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET LAYER 4
DTIVIEW>

SET LINE_STYLE COMMAND

--------------------------------------------------------------------------------
SET LINE_STYLE

--------------------------------------------------------------------------------

FORMAT:		 SET LINE_STYLE line_number

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET LINE_STYLE command is used to select the line style in which lines will be drawn on a TEKTRONIX 4014 display, when ISOMETRIC, PERSPECTIVE and OVERLAY commands are given.

By default a solid line representation is used.

Use of the SHOW SETTINGS command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET LINE_STYLE commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET LINE_STYLE
Command requires 1 integer argument

*** ERROR *** Specifying command SET LINE_STYLE
Command requires an integer value in the range 1 to 5

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET LINE_STYLE 2
DTIVIEW>

SET NULL_FC COMMAND

--------------------------------------------------------------------------------
SET NULL_FC

--------------------------------------------------------------------------------

FORMAT:		 SET NULL_FC feature_code

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET NULL_FC command is used to specify the code given to features in the IFF output file that are profiles with heights outside the height range defined with the ZLIMITS command.

By default these features are given a code of 3. This allows the IFF data to be plotted, so that these profiles may be distinguished in a different colour or line style.

The command is only relevant when using the ENABLE IFF_OUTPUT option, to write a terrain view to an IFF file.

Use of the SHOW SETTINGS command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET NULL_FC commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET NULL_FC
Command requires 1 integer argument

*** ERROR *** Specifying command SET NULL_FC
Command requires a feature code in the range 1 to 32767

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET NULL_FC 14
DTIVIEW>

SET ORIGIN COMMAND

--------------------------------------------------------------------------------
SET ORIGIN

--------------------------------------------------------------------------------

FORMAT:		 SET ORIGIN x_origin y_origin

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET ORIGIN command is used to define a drawing origin. This determines where the bottom lefthand corner of the graphics drawing area is located. The origin values are specified in normalised device coordinates. For example, if an origin of 0.5 and 0.5 is specified, then only the upper righthand quadrant of the screen will be used.

The command is used in conjunction with the SET SCALE command to override the default scaling and positioning of the terrain view.

; Giving the command SET ORIGIN will automatically disable the AUTOSCALE option. This option can be reselected using the command ENABLE AUTOSCALE. If AUTOSCALE is selected, then drawing scale factor and origin values are automatically calculated, and applied in preference to any user supplied drawing scale and origin values.

Use of the SHOW SETTINGS or SHOW DEVICE command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET ORIGIN commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET ORIGIN
Command requires 2 real arguments

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET ORIGIN 0.3 0.3
DTIVIEW>

SET SCALE COMMAND

--------------------------------------------------------------------------------
SET SCALE

--------------------------------------------------------------------------------

FORMAT:		 SET SCALE scale_factor

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET SCALE command is used to define a drawing scale factor. This determines the amount of enlargement that is applied to the terrain view and any vector overlay when output to a graphics device. The command is used in conjunction with the SET ORIGIN command to override the default scaling and positioning of the terrain view.

Giving the command SET SCALE will automatically disable the AUTOSCALE option. This option can be reselected using the command ENABLE AUTOSCALE. If AUTOSCALE is selected, then drawing scale factor and origin values are automatically calculated, and applied in preference to any user supplied drawing scale and origin values.

Use of the SHOW SETTINGS or SHOW DEVICE command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET SCALE commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET SCALE
Command requires 1 real argument

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET SCALE 1.5
DTIVIEW>

SET SEA_FC COMMAND

--------------------------------------------------------------------------------
SET SEA_FC

--------------------------------------------------------------------------------

FORMAT:		 SET SEA_FC feature_code

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET SEA_FC command is used to specify the code which is given to features in the IFF output file that are profiles across the sea surface.

By default such features are given a feature code of 2, and features that define a line across the land surface are given a feature code of 1. This allows the IFF data to be plotted, so that the land and sea may be distinguished in different colours or line styles.

The command SET LAND_FC should be used to set the feature code of profiles across the land surface.

The command is only relevant when using the ENABLE IFF_OUTPUT option, to write a terrain view to an IFF file.

Use of the SHOW SETTINGS command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET SEA_FC commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET SEA_FC
Command requires 1 integer argument

*** ERROR *** Specifying command SET SEA_FC
Command requires a feature code in the range 1 to 32767

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET SEA_FC 4
DTIVIEW>

SET SYMBOL_SCALE COMMAND

--------------------------------------------------------------------------------
SET SYMBOL_SCALE

--------------------------------------------------------------------------------

FORMAT:		 SET SYMBOL_SCALE scale_factor

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET SYMBOL_SCALE command is used to specify a symbol enlargement factor, and therefore controls the representation of drawn symbols. It is a value by which the normalised SRI symbol coordinates are enlarged or reduced prior to output to a graphics device.

By default DTIVIEW will use the scale entry in the FRT and the dimensions of the graphics screen to determine the symbol size, however is some situations it is useful to override the default value.

Use of the SHOW SETTINGS command is recommended to check on the current setting.

The command is only valid if the ENABLE OVERLAY command has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET SYMBOL_SCALE commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET SYMBOL__SCALE
Command requires 1 real argument

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET SYMBOL_SCALE 4.5
DTIVIEW>

SET TEXT_FC COMMAND

--------------------------------------------------------------------------------
SET TEXT_FC

--------------------------------------------------------------------------------

FORMAT:		 SET TEXT_FC feature_code

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SET TEXT_FC command is used to specify the code which is given to the title text feature in the IFF output file.

By default this feature is given a feature code value of 64.

The command is only relevant when using the ENABLE IFF_OUTPUT option.

Use of the SHOW SETTINGS command is recommended to check on the current setting.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SET and SET TEXT_FC commands:


*** ERROR *** Specifying command SET
Command qualifiers are DEFAULT, LAND_FC, LAYER, LINE_STYLE,
		       NULL_FC, ORIGIN, SCALE, SEA_FC, SYMBOL_SCALE
		       TEXT_FC

*** ERROR *** Specifying command SET TEXT_FC
Command requires 1 integer argument

*** ERROR *** Specifying command SET TEXT_FC
Command requires a feature code in the range 1 to 32767

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SET TEXT_FC 100
DTIVIEW>

SETUP MAP COMMAND

--------------------------------------------------------------------------------
SETUP MAP

--------------------------------------------------------------------------------

FORMAT:		 SETUP MAP

--------------------------------------------------------------------------------
DESCRIPTION:

The SETUP MAP command allows a source document to be registered to the input DTM.

In order to register the map and a DTM, the DTM should have first been specified, and a source document should have been securely attached to the surface of a digitising table.

On giving the command you will be asked to digitise 4 rectangular registration points. The registration points represent 4 points on the map that correspond to the 4 corners of the DTM. The points are digitised in the order top left (NW), bottom left (SW), bottom right (SE) and top right (NE) using any button on the table puck. A point should be digitised in response to a prompt on the terminal.
An error message is generated if any of the angles of the digitised rectangle are less than 88 degrees, or greater than 92 degrees (ie. if the corner points of the rectangle are more than 2 degrees off rectangular). In this case you will be asked to redigitise the 4 registration points.
Setup of the map may be aborted using (pressing the Ctrl and Z keys together).

Following the registration of a map to the DTM, coordinate values required by the WINDOW and PROFILE commands, may be input using the table puck. User defined symbols may also be positioned using the table puck.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SETUP and SETUP MAP commands:


*** ERROR *** Specifying command SETUP
Command qualifiers are MAP or MENU

*** ERROR *** Specifying command SETUP MAP
Command is invalid if the table has not been initialised

*** ERROR *** Specifying command SETUP MAP
The input DTM must be specified before SETUP MAP

*** ERROR *** Setting up MAP
Badly digitised corner points; try again

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SETUP MAP


Digitise map NW corner>

Digitise map SW corner>

Digitise map SE corner>

Digitise map NE corner>


DTIVIEW>

SETUP MENU COMMAND

--------------------------------------------------------------------------------
SETUP MENU

--------------------------------------------------------------------------------

FORMAT:		 SETUP MENU

--------------------------------------------------------------------------------
DESCRIPTION:

The SETUP MENU command allows the DTIVIEW menu to be positioned on the digitising table.

On giving the command you will be asked to digitise the 4 corners points of the menu. The corners are digitised in the order top left (NW), bottom left (SW), bottom right (SE) and top right (NE) using any button on the table puck. A point should be digitised in response to a prompt on the terminal.
An error message is generated if any of the angles of the digitised rectangle are less than 88 degrees, or greater than 92 degrees (ie. if the corner points of the rectangle are more than 2 degrees off rectangular). In this case you will be asked to redigitise the 4 menu corner points.
Setup of the menu may be aborted using (pressing the Ctrl and Z keys together).

Once a menu has been positioned on the table, it is possible to enter many of the DTIVIEW commands by digitising a point in the appropriate menu box. If a command requires a parameter argument, you should enter the parameter in response to the prompt on the terminal, using the keyboard.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SETUP and SETUP MENU commands:


*** ERROR *** Specifying command SETUP
Command qualifiers are MAP or MENU

*** ERROR *** Specifying command SETUP MENU
Command is invalid if the table has not been initialised

*** ERROR *** Setting up MENU
Badly digitised corner points; try again

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SETUP MENU


Digitise menu NW corner>

Digitise menu SW corner>

Digitise menu SE corner>

Digitise menu NE corner>


DTIVIEW>

SHOW ANNOTATION COMMAND

--------------------------------------------------------------------------------
SHOW ANNOTATION

--------------------------------------------------------------------------------

FORMAT:		 SHOW ANNOTATION

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

The command SHOW ANNOTATION displays information on the current position, size and colour of a label, and the current position and size of a legend.

These parameters may be varied using the appropriate LABEL or LEGEND commands.

If the SHOW ANNOTATION command is given before any LABEL or LEGEND commands, the default annotation parameter settings may be examined.

--------------------------------------------------------------------------------
Messages:

The following messages are specific to the SHOW command:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW ANNOTATION


Label Position  : 0.500 0.500
Label Size      : 1
Label Colour    : 1

Legend Position : 0.005 0.150
Legend Size     : 0.25


DTIVIEW>

SHOW DEVICE COMMAND

--------------------------------------------------------------------------------
SHOW DEVICE

--------------------------------------------------------------------------------

FORMAT:		 SHOW DEVICE

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

The command SHOW DEVICE displays information on parameters that are associated with a graphics device. The status of the graphics device is shown, along with details on the current bit-plane and colour allocation. The drawing origin and scale values are also shown.

--------------------------------------------------------------------------------
Messages:

The following messages are specific to the SHOW command:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW DEVICE

 
PRIMARY           On       SECONDARY        Off       

5 Planes allocated to PICTURE 1
3 Planes allocated to PICTURE 2

Maximum number of colours  for terrain view : 29
Number of colours selected for terrain view : 29
Maximum number of overlay colours           : 7

Divided screen is enabled
Current quadrant number : 1

AUTOSCALE is enabled


DTIVIEW>

SHOW ENABLE COMMAND

--------------------------------------------------------------------------------
SHOW ENABLE

--------------------------------------------------------------------------------

FORMAT:		 SHOW ENABLE

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

Displays the current status of all the DTIVIEW options that may be enabled or disabled using the ENABLE and DISABLE commands.
The name of the option is shown, followed by either the word ON or OFF to indicate its current status.
If the command SHOW ENABLE is used before any ENABLE or DISABLE commands have been given, the default status of the options is displayed.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the SHOW command:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW ENABLE


Current status:

ABSOLUTE         On        AUTOSCALE        On       BATHYMETRY       Off

COLOUR_IFF       Off       DIVIDE           Off	     FISHNET          Off

FOG              Off       GRAPHICS         Off	     IFF_OUTPUT       On

OVERLAY          Off       PICTURE 1        Off      PICTURE 2        Off

PRIMARY          Off       SECONDARY        Off	      SYMBOLS         Off

TABLE            Off


DTIVIEW>

SHOW FILEIN COMMAND

--------------------------------------------------------------------------------
SHOW FILEIN

--------------------------------------------------------------------------------

FORMAT:		 SHOW FILEIN

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

Details extracted from the header of the DTM are displayed on the terminal, along with details of the current window or area of interest.

The header values are shown in the current units of measurement. This is dependent on the header type of the input file, or may be set explicitly using the UNITS command. By default or if the ENABLE ABSOLUTE command has been given then metre or projection values are expressed in absolute values. Otherwise they are displayed as offsets from the SW corner of the matrix.

--------------------------------------------------------------------------------
Messages:

The following messages are specific to the commands SHOW and SHOW FILEIN:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW

*** WARNING *** The input DTM is undefined

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW FILEIN


LSL$DTI:TEST.DTI	
Header: MIKE	 Data: WORD

Units are DTI Matrix Values

Matrix Coverage    SW:    1     1    NE:   301   251
Matrix Window      SW:    1     1    NE:   200   200
Matrix Interval	    E:	  1	      N:     1
Value Range	     :      0   to    851


DTIVIEW>

SHOW IFF COMMAND

--------------------------------------------------------------------------------
SHOW IFF

--------------------------------------------------------------------------------

FORMAT:		 SHOW IFF

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

Displays information on the currently selected IFF file.

The name of the IFF file, and the IFF coordinate range and window settings are shown. By default or if the ENABLE ABSOLUTE command has been given, then the coordinates are expressed as absolute values. Otherwise they are displayed as offset values from the SW corner of the file area.

--------------------------------------------------------------------------------
Messages:

The following messages are specific to the SHOW and SHOW IFF commands:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW

*** WARNING *** The input IFF file is undefined

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW IFF


IFF file:       LSL$IF:TEST.IFF
IFF file range:
SW: 270000.00 180000.00   NE: 310000.00  220000.00
IFF file window :
SW: 280000.00 190000.00   NE: 320000.00  190000.00


DTIVIEW>

SHOW SETTINGS COMMAND

--------------------------------------------------------------------------------
SHOW SETTINGS

--------------------------------------------------------------------------------

FORMAT:		 SHOW SETTINGS

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

Displays the name of all DTIVIEW parameters that may be set using the SET command, and their current values.
If the SHOW SETTINGS command is given before using a SET command, the values shown are the default values that are allocated to the parameters by COVER.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the command SHOW:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW


--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW SETTINGS

 
Current Settings:

LAND_FC          1       LAYER            1       LINE_STYLE       1

ORIGIN      0.01  0.51   NULL_FC          3       SCALE         0.47

SEA_FC           2       SYMBOL_SCALE 602.59      TEXT_FC         64

DTIVIEW>

SHOW SYMBOLS COMMAND

--------------------------------------------------------------------------------
SHOW SYMBOLS

--------------------------------------------------------------------------------

FORMAT:		 SHOW SYMBOLS

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

The SHOW SYMBOLS command displays information about the currently defined symbols.

If the ENABLE SYMBOLS and the SYMBOL FC commands have been previously given the SHOW SYMBOLS command will display the number of symbols currently defined.

If the SYMBOL POSITION command has been given or the table puck has been used to position symbols, the SHOW SYMBOLS command will additionally display the x and y coordinate position of a symbol and its visibility status. The coordinates are shown in the current units of measurement. This is dependent on the header type of the input file, or may be set explicitly using the UNITS command. By default, or if the ENABLE ABSOLUTE command has been given , then metre or projection values are expressed in absolute values. Otherwise they are displayed as offsets from the SW corner of the matrix.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the command SHOW:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW


--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW SYMBOLS<CR>


Number of symbols currently defined : 9
Number of symbols currently used : 4
--------------------------------------------------------------|
| Symbol no |   FC  |   X position  |   Y position  | Visible |
--------------------------------------------------------------|
|      1    |    1  |        10     |        10     |   YES   |
|      2    |    2  |        20     |        20     |   YES   |
|      3    |    3  |        30     |        30     |   YES   |
|      4    |    4  |        40     |        40     |   YES   |
--------------------------------------------------------------|

DTIVIEW>

SHOW VIEW COMMAND

--------------------------------------------------------------------------------
SHOW VIEW

--------------------------------------------------------------------------------

FORMAT:		 SHOW VIEW

--------------------------------------------------------------------------------
Command parameters: None.

--------------------------------------------------------------------------------
DESCRIPTION:

The SHOW VIEW command displays on the terminal the current value of all view parameters.

These are the parameters that control how the DTM is sampled, and the transformations that are applied, when generating an isometric or perspective terrain view. Values defined using the ZSTEP and ZLIMITS commands are also displayed.

--------------------------------------------------------------------------------
Messages:

The following message is specific to the command SHOW:


*** ERROR *** Specifying command SHOW
Command qualifiers are ANNOTATION, DEVICE, ENABLE, IFF, FILEIN
                       SELECTIONS, SETTINGS, SYMBOLS or VIEW


--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW VIEW


Theta                : -30.0
Phi                  : 45.0
Viewing direction    : From the WEST 
Vertical exaggeration: 1.0
Viewing distance     : 300.0
Height of view       : 1000.0

Fog colour index     : 0
Visibility distance  : 1000.0

Z Limits             : 0 to 833
Z Step               : 29

Sampling interval along columns : 1
Sampling interval along rows    : 1


DTIVIEW>

SPAWN COMMAND

--------------------------------------------------------------------------------
SPAWN

--------------------------------------------------------------------------------
FORMAT: SPAWN command-line

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SPAWN command enables you to create a subprocess while within DTIVIEW. When the subprocess terminates, control is returned to DTIVIEW.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SPAWN command:


*** ERROR *** Specifying command SPAWN 
Command requires a valid DCL command line

*** ERROR *** Specifying command SPAWN 
DCL command line cannot exceed 80 characters

*** ERROR *** Unable to spawn command, returning to DTIVIEW

--------------------------------------------------------------------------------
Examples:

DTIVIEW> SPAWN DIRECTORY LSL$DTI:*_._DTI

Directory DUA3:[LSL.DTI]
TEST1_.DTI;1              8/8       18-AUG-1987 07:56  [LSL,DAVEC]
TEST2_.DTI;1              7/8       18-AUG-1987 17:17  [LSL,DAVEC]
TEST2_.DTI;2              7/8       18-AUG-1987 17:34  [LSL,DAVEC]
Total of 3 files, 22/24 blocks.

DTIVIEW>

SRI COMMAND

--------------------------------------------------------------------------------
SRI

--------------------------------------------------------------------------------

FORMAT:	        SRI file-spec

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

This command reads the specified Symbol Representation IFF file.
It is only appropriate to the overlay of vector data or plotting of symbols on a terrain view.

The SRI determines how any IFF symbol or symbol-string features will appear graphically, when overlaid on a terrain view using the command OVERLAY.

The SRI file is optional, and need only be provided if the IFF file contains features that are to be symbolically represented.

The command is only valid if the ENABLE OVERLAY or the ENABLE SYMBOLS has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SRI command:


*** ERROR *** Specifying command SRI
Overlay or symbols options are not enabled

*** ERROR *** Specifying command SRI
Input SRI filename is missing

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SRI DTIVIEW.SRI
DTIVIEW>

SYMBOL CLEAR COMMAND

--------------------------------------------------------------------------------
SYMBOL CLEAR

--------------------------------------------------------------------------------

FORMAT:		SYMBOL CLEAR ALL

or

FORMAT:		SYMBOL CLEAR symbol_number

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SYMBOL CLEAR command is used to clear a symbol or all symbols from the graphics screen. The symbols are cleared independently of any perspective or isometric terrain view.

The command is only valid if the ENABLE SYMBOLS command has been previously given.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SYMBOL and SYMBOL CLEAR commands:


*** ERROR *** Specifying command SYMBOL
Symbol options are not enabled
Use ENABLE SYMBOLS command

*** ERROR *** Specifying command SYMBOL CLEAR
Command requires symbol number

*** ERROR *** Specifying command SYMBOL CLEAR
Error reading integer number

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW SYMBOLS<CR>


Number of symbols currently defined : 9
Number of symbols currently used : 4
--------------------------------------------------------------|
| Symbol no |   FC  |   X position  |   Y position  | Visible |
--------------------------------------------------------------|
|      1    |    1  |      270.00   |      270.00   |   YES   |
|      2    |    2  |      570.00   |      570.00   |   YES   |
|      3    |    3  |      870.00   |      870.00   |   YES   |
|      4    |    4  |     1170.00   |     1170.00   |   YES   |
--------------------------------------------------------------|

DTIVIEW>SYMBOL CLEAR 1<CR>

DTIVIEW>SHOW SYMBOLS<CR>


Number of symbols currently defined : 9
Number of symbols currently used : 3
--------------------------------------------------------------|
| Symbol no |   FC  |   X position  |   Y position  | Visible |
--------------------------------------------------------------|
|      2    |    2  |      570.00   |      570.00   |   YES   |
|      3    |    3  |      870.00   |      870.00   |   YES   |
|      4    |    4  |     1170.00   |     1170.00   |   YES   |
--------------------------------------------------------------|


DTIVIEW>

SYMBOL FC COMMAND

--------------------------------------------------------------------------------
SYMBOL FC

--------------------------------------------------------------------------------

FORMAT:		SYMBOL FC symbol_number feature_code

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SYMBOL FC command is used to define a symbol and its feature code. Up to fifteen symbols may be defined using the SYMBOL FC command.

The SYMBOL FC command checks that the feature code specified is a valid symbol in the FRT file. If the symbol is not valid an error message will be generated. The SYMBOL FC command must be given prior to issuing the SYMBOL POSITION command or before positioning the symbol using the table puck.

The command is only valid if the ENABLE SYMBOLS command has been previously given. A FRT file and a SRI file, must have been previously defined.

The SHOW SYMBOLS command should be used to display information about the symbols defined and in use.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SYMBOL and SYMBOL FC commands:

*** ERROR *** Specifying command SYMBOL
Command qualifiers are CLEAR, FC or POSITION

*** ERROR *** Specifying command SYMBOL
Symbol options are not enabled
Use ENABLE SYMBOLS command

*** ERROR *** Specifying command SYMBOL
No FRT file has been specified
Use FRT command

*** ERROR *** Specifying command SYMBOL
No SRI file has been specified
Use SRI command

*** ERROR *** Specifying command SYMBOL FC
Command requires 2 integer arguments 
eg SYMBOL FC  

*** ERROR *** Specifying command SYMBOL FC
Feature code  is not a point symbol

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SYMBOL FC 1 57<CR>
DTIVIEW>SYMBOL POSITION 1 10 20<CR>

DTIVIEW>SHOW SYMBOLS<CR>


Number of symbols currently defined : 1
Number of symbols currently used : 1
--------------------------------------------------------------|
| Symbol no |   FC  |   X position  |   Y position  | Visible |
--------------------------------------------------------------|
|      1    |   57  |      10       |      20       |   YES   |
--------------------------------------------------------------|


DTIVIEW>

SYMBOL POSITION COMMAND

--------------------------------------------------------------------------------
SYMBOL POSITION

--------------------------------------------------------------------------------

FORMAT:		SYMBOL POSITION symbol_number x_coord y_coord

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The SYMBOL POSITION command is used to position a symbol on the terrain model. If the symbol is already shown on the terrain model, the command undraws the symbol at its current location and draws the symbol at the new location. Should the location specified be not be visible to the observer, then the symbol will not be drawn at the new location. Up to fifteen symbols can be positioned using the SYMBOL POSITION command.

Note: If the base of the symbol is not visible to the observer then no part of the symbol is drawn irrespective of the height of the symbol.

The size of the symbols is controlled by means of the size entry in the FRT and the SET SYMBOL_SCALE command.

If a digitising table is available, and a map has been registered to the DTM then the symbol may be positioned on the terrain model using the appropriate button on the table puck. Button 1 defines the position of symbol 1, button 2 defines the position of symbol 2 and so on. All fifteen symbols may be position in this way. Button 0 allows all previously defined and used symbols to be redisplayed. This is particularly useful when a new view is generated.

The command is only valid if the ENABLE SYMBOLS command has been previously given. A FRT file and a SRI file, must have been previously defined.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the SYMBOL and SYMBOL POSITION commands:


*** ERROR *** Specifying command SYMBOL
Symbol options are not enabled
Use ENABLE SYMBOLS command

*** ERROR *** Specifying command SYMBOL
Symbol plotting not possible with a plane setting of 8

*** ERROR *** Specifying command SYMBOL
No FRT file has been specified
Use FRT command

*** ERROR *** Specifying command SYMBOL
No SRI file has been specified
Use SRI command

*** ERROR *** Specifying command SYMBOL
Command qualifiers are CLEAR, FC or POSITION

*** ERROR *** Specifying command SYMBOL POSITION
Command requires symbol number and x,y coordinate pair

*** ERROR *** Specifying command SYMBOL POSITION
Symbol number less than 1 or greater than 15

*** ERROR *** Specifying symbol position 
Unable to use supplied LATLONG values

--------------------------------------------------------------------------------
Examples:

DTIVIEW>SHOW SYMBOLS<CR>


Number of symbols currently defined : 9
Number of symbols currently used : 5
--------------------------------------------------------------|
| Symbol no |   FC  |   X position  |   Y position  | Visible |
--------------------------------------------------------------|
|      1    |   95  |      51       |      26       |   YES   |
|      2    |  120  |      52       |      70       |   NO    |
|      3    |   54  |      60       |      60       |   YES   |
|      4    |   55  |      65       |      70       |   YES   |
|      5    |   56  |      75       |      52       |   YES   |
--------------------------------------------------------------|

DTIVIEW>SYMBOL POSITION 2 53 30<CR>

DTIVIEW>SHOW SYMBOLS<CR>


Number of symbols currently defined : 10
Number of symbols currently used : 5
--------------------------------------------------------------|
| Symbol no |   FC  |   X position  |   Y position  | Visible |
--------------------------------------------------------------|
|      1    |   95  |      51       |      26       |   YES   |
|      2    |  120  |      53       |      30       |   NO    |
|      3    |   54  |      60       |      60       |   YES   |
|      4    |   55  |      65       |      70       |   YES   |
|      5    |   56  |      75       |      52       |   YES   |
--------------------------------------------------------------|


DTIVIEW>

THETA COMMAND

--------------------------------------------------------------------------------
THETA

--------------------------------------------------------------------------------

FORMAT:		 THETA  rotation

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The command THETA defines the degree of rotation in the y axis that is applied to an isometric terrain view. It therefore defines the tilt that is applied to the isometric view.

The default value of THETA is -30.0 degrees.

Use of the SHOW VIEW command is recommended to check on the y rotation value before a terrain view is generated.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the THETA command:


*** ERROR *** Specifying command THETA
Command requires 1 real argument

*** ERROR *** Specifying command THETA
Command requires a rotation value in the range 0 to -90 degrees

--------------------------------------------------------------------------------
Examples:

DTIVIEW>THETA -20.0
DTIVIEW>

UNITS COMMAND

--------------------------------------------------------------------------------
UNITS

--------------------------------------------------------------------------------
FORMAT: UNITS units

--------------------------------------------------------------------------------
Command parameters:

--------------------------------------------------------------------------------
DESCRIPTION:

The UNITS command defines the units of measurement that will be used when defining an area of interest in the input DTM by means of the WINDOW command, when defining the start and end of a profile using the PROFILE command or defining a symbol position with the SYMBOL POSITION command.
The command also controls in what format coordinate information is output when the SHOW FILEIN or SHOW SYMBOLS commands are given.
The command should be given after defining the input DTI file, since an appropriate default units of measurement is set up whenever an input DTI file is opened.

--------------------------------------------------------------------------------
Messages:

The following error messages are specific to the UNITS command:


*** ERROR *** Specifying command UNITS
Command qualifiers are MATRIX, METRES, SECONDS, LATLONG or PROJECTION

*** ERROR *** Specifying command UNITS
Command qualifier is invalid for the input file

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Examples:


DTIVIEW> UNITS MATRIX<CR>
DTIVIEW>

WAIT COMMAND

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WAIT

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FORMAT: WAIT seconds

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Command parameters:

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DESCRIPTION:

The WAIT command causes processing to be suspended for a specified number of seconds. It is designed for use in software demonstration situations and is of no value in a production flowline.

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Messages:

The following error message is specific to the WAIT command:


*** ERROR *** Specifying command WAIT
Command requires a real argument

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Examples:


DTIVIEW> WAIT 4.0<CR>
DTIVIEW>

WINDOW COMMAND

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WINDOW

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FORMAT:		WINDOW  xmin ymin xmax ymax

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Command parameters:

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DESCRIPTION:

The WINDOW command is used to define a rectangular geographical area of interest in the DTM. Only nodes that lie within this area are used when generating an isometric or perspective terrain view.
The specified area of interest should lie within the geographical bounds of the DTM.
If the logical name LSL$MATRIX_DEFAULT_WINDOW is defined with a value of "1", then a default area of interest defined in matrix units of bottom left hand corner 1,1 and top right hand corner 200,200 is set when the file is opened. If the logical name is absent or has any other value, or if the input DTI file has fewer than 200 columns or 200 rows, then a default window equivalent to the total matrix is set.

If a digitising table is available, and a map has been registered to the DTM, the coordinates of the window may be defined using any button on the table puck.

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Messages:

The following messages are specific to the WINDOW command:


*** ERROR *** Specifying command WINDOW
The input DTM must be specified before WINDOW

*** ERROR *** Specifying command WINDOW using puck button
No map set up has been performed

*** ERROR *** Specifying command WINDOW
Command requires 4 arguments

*** ERROR *** Specifying command WINDOW
NE corner values must exceed SW corner values

*** ERROR *** Specifying command WINDOW
Supplied values exceed matrix extents

*** ERROR *** Specifying command WINDOW
Latitude and longitude values supplied in wrong format

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Examples:

DTIVIEW>WINDOW 1 1 200 200
DTIVIEW>UNITS LATLONG
DTIVIEW>WINDOW 42 00 00N 3 00 00E 42 30 00N 2 58 40E
DTIVIEW>

ZLIMITS COMMAND

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ZLIMITS

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FORMAT:		 ZLIMITS lower_height upper_height

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Command parameters:

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DESCRIPTION:

The ZLIMITS command restricts the allocation of colours to profile vectors that have height values that lie within the specified height range. Profile vectors that lie outside the height range are shown in white when the terrain view is displayed on a colour graphics device, or are given a null feature code value when written to an output IFF file.

The supplied height values must lie within the minimum and maximum height values of the input DTM range.

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Messages:

The following error messages are specific to the ZLIMITS command:


*** ERROR *** Specifying command ZLIMITS
Command requires 2 integer arguments

*** ERROR *** Specifying command ZLIMITS
Upper height value must exceed the lower height value

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Examples:

DTIVIEW>HEIGHT RANGE 50 250CR>
DTIVIEW>

ZSCALE COMMAND

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ZSCALE

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FORMAT:	        ZSCALE scale_factor

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Command parameters:

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DESCRIPTION:

The ZSCALE command defines a vertical exaggeration (z scale) factor. This is a value by which all DTM height values are multiplied before a profile, or an isometric or perspective view is generated.

By default no vertical exaggeration is applied ie. a z scale factor of 1 is used.

Use of the SHOW VIEW command is recommended to check on the status of the parameter before an isometric or perspective view is generated.

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Messages:

The following error messages are specific to the ZSCALE command:


*** ERROR *** Specifying command EXAGGERATION
Command requires 1 real argument

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Examples:

DTIVIEW>ZSCALE 2.5
DTIVIEW>

ZSTEP COMMAND

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ZSTEP

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FORMAT:		 ZSTEP height_interval

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Command parameters:

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DESCRIPTION:

The ZSTEP command defines the height interval value that is used when displaying an isometric or perspective view on a colour graphics device.

A unique colour is allocated to each height band when the terrain view is drawn. For example if a ZSTEP interval of 100 is used, profile vectors generated from DTM nodes that fall within the range 1 to 100 will be shown in one colour, while profile vectors associated with DTM nodes with values in the range 101 to 200 will be shown in a different colour. Using this command it is possible to produce a height banded or layered terrain view for validation or analysis purposes.

The command may be used in conjunction with the ZLIMITS command.

When the DTM is first specified a default ZSTEP value is calculated by dividing the height range in the file by the default number of display colours appropriate to the current planes setting. Changing the number of display colours using the COLOURS command will alter the default ZSTEP value.

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Messages:

The following error message is specific to the ZSTEP command:


*** ERROR *** Specifying command ZSTEP
Command requires 1 integer argument

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Examples:

DTIVIEW>ZSTEP 50<CR>
DTIVIEW>

MESSAGES (OTHER)

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MESSAGES (OTHER)

In addition to messages which are generated by the program itself, other messages may be produced by Laser-Scan libraries. In particular, messages may be generated the DTI library, and by the Laser-Scan I/O library, LSLLIB.

DTI library messages are introduced by '%DTI', and are documented in the DTILIB Reference Manual. In all cases the messages indicate a fatal error, that will cause processing to halt.

LSLLIB messages are introduced by '%LSLLIB' and are generally self-explanatory. Such messages rarely indicate a fatal error, and are generated most frequently by entering a command in an invalid format in response to the DTIVIEW prompt.