Modify DTM

Module(s): Digital Terrain Model

You can use the Modify DTM tool to change the smoothing factor, the type of labels used for grid points, the location of contour labeling, and the number of decimal places in contour labels. The defaults for these values are set in the Options and can be modified for single DTMs using this tool.

In addition, you can control how textures are displayed in animation.

To modify a digital terrain model

1. Click Modify DTM (How).
   

   Activate Modify DTM in one of the following ways

   • Menu bar: Modify Terrain Digital Terrain Model

   • Palette: Tools Change area in the following module(s):

   Digital Terrain Model

   • Configuration: Landscaping/Urban Planning Digital Terrain Model flyout
2. Click the DTM you want to modify.
3. On the context toolbar, click the parameters to change their settings:
   • Smoothing factor
     

     You can use this to set a smoothing factor for the model and consequently define the type of interpolation. With linear models, the computation is based solely on the initial data used. Setting a smoothing factor between 1 and 10, however, will result in a ”smoother” interpolation within each mesh triangle. This will make contours appear more ”rounded.” The factor only affects contour lines, elevation points and interpolations, and not cut and fill, slope and surface calculations, etc. The higher the factor, the more time is required for large models.

     Linear model with a smoothing factor of 0

     Smoothed model with a smoothing factor of 5

     Notes:

     • If contours are calculated with a smoothing factor of, say, 10 and then later optimized for the linear model, the contour lines may disappear, as they do not exist in the DTM.
     • The default for the smoothing factor is set in the Options.
   • Point label type
     

     You can use this option to specify whether DTM point labels include the point’s height, number, height+number or label.

     Note: You can set a default for the point label type in the Options.

   • Location of contour line labels
     

     You can use this option to specify whether contour line labels are displayed above, below or centered on the line.

     Note: You can set a default for the location of contour line labels in the Options.

   • Decimal places in contour line labels
     

     You can specify up to 3 decimal places for contour line labels.

     Note: You can specify the default for the number of decimal places in the Options.

4. Use the T Plan box to specify how a texture in plan view is displayed in animation. If necessary, enter a direction angle for the texture.
   

   You can use the T Plan box to specify how a texture is displayed in animation.

   • When this box is not checked, the texture is assigned to each individual area in all views. The program takes the inclination of each area into account.
   • When this box is checked, the texture is assigned to the entire DTM in plan view. The program projects the texture to plan view without taking into account the angles of inclination of the individual areas.
     This way, you can display a realistic image of a photo taken on board a plane.

   Note: You can specify the position of the texture in the Surface Settings, Displace area.

5. Click OK to confirm the settings. You can also click in the workspace with the right mouse button.