DTMs and 3DMs
This function displays and sets the drawing styles for a specified triobject interval.
To run this function: Choose Display > Display properties > DTM's and 3DM's, or Customise > Display properties > DTM's and 3DM's, or...
Drawing styles include the presentation attributes for:
- a label for the style - this is not used at this time
- line colour
- line thickness
- line pattern
- face colour
- specular reflectance colour - the colour of the shiny spots
- transmission colour - for transparency effects
- gloss effects - the size of the shiny spots
- face pattern
- edge colour
- edge thickness
- edge pattern
- text colour
- marker symbol
- marker size
The Set Drawing Styles form is displayed. It contains the following fields.
Object Range
Enter the range for which the drawing styles in this row are to apply. For example, 10, 20, 5 or 10;15;20.
If any object number has been defined twice, the lower styles row is used.
Label
The label is not mandatory and is may be used in the future if legend drawing is provided for objects.
Colours
Edges
Define the colours which will be used for the triangle edges that comprise a DTM or solid. Left click the mouse in the data entry field to display a Properties menu. Choose the Properties item from the shortcut menu to display the Edit Properties form.
Line properties that may be altered on this form include:
Colour
This is the colour that will be used for drawing the triangle edges.
Thickness
This is the thickness of the lines that will be used for drawing the triangle edges.
Style
This is the line style for drawing the triangle edges. A variety of line styles form a full line through to various dot and dash patterns may be used.
Join type
The joins of line segments may be rendered in a number of styles.
End type
The ends of lines, not that these exist for triangle edges, may be chosen from a variety of styles.
Faces
Define the colours which will be used for the triangle faces that comprise a DTM or solid. Left click the mouse in the data entry field to display a Properties menu. Choose the Properties item from the shortcut menu to display the Edit Properties form.
Triangle rendering properties that may be altered on this form include:
Colour
This is the basic colour of the triangle face.
Reflectance colour
This is the colour of light that is reflected from the shiny spot on a triangle face when lights are simulated in the scene.
With most nonmetallic objects, the specular reflection colour is a shade of white. A specular reflectance colour of black results in a dull, non-specular surface, while a value of white gives a shiny material.
Metallic surfaces, however, tend to have coloured reflections. For example, the `glare' from a piece of polished brass illuminated by white light has a yellow-orange tint. This tint could be described by a specular reflectance value of `orangish white'.
The specular response of a material also depends on its gloss value.
Transparency colour
This is the colour that can show through the triangle faces. The Transparency Colour check box must be ticked for this item to be accessible. Transparency calculations are very compute intensive. Consequently they are only used when special effects are required, for presentation quality output for example. The benefit of transparency though is that objects can be made translucent to show details inside the objects.
Style
This is the colour of polygon edges that are drawn.
Thickness
This is the thickness of the lines that are drawn for any polygon edges.
Glossiness
The gloss value changes the area of the glare off a surface - a high gloss value gives a small glare, while a low gloss value results in a less polished, more scattered reflection.
Pattern
Triangle faces may be rendered as a solid colour or in a range of pre-defined patterns.
Markers
Define the marker symbol and size for drawing markers at points. Left click the mouse in the data entry field to display a Properties menu. Choose the Properties item from the shortcut menu to display the Edit Properties form. On the Edit Properties form, you can select the style of marker, and the size of the marker.
The standard marker size of 1 creates markers which are 3% of the screen height. Other values for markers size are proportional to this.
Note: Changes made to the drawing styles will normally be made to any DTM data presently drawn in a graphics viewport after the Apply button is pressed. This will not be the case if the DTM has been drawn with the special colour banding presentation that is useful for advanced rendering requirements.
DTM/Solid Properties
This function permits the display properties of a DTM or solid object to be modified by selecting the object graphically. The object properties that can be modified are identical to those as described in the documentation above so are not repeated here.
To run this function: Choose Display > DTM/Solids properties, or...
Select the triangle of interest
Position the mouse and select the triangle on the DTM or solid whose properties are to be modified to display the Object Drawing Properties form.
Modify the display properties as required and press the Apply button to change the display properties of the selected DTM or solid.