How to adjust the height map with a combo overlay

From Tygron Support wiki
Jump to: navigation, search

It is now possibe to change the Digital Terrain Model (DTM) of a project, by using a Combo Overlay.

In the following example the roads of the project area will be lowered with 20cm - useful for e.g. simulating kerbs.

How to adjust the height map with a combo overlay.:

  1. Add a DTM Height Map Overlay to your project.
  2. Add an Average Overlay that selects a specified attibute. This can be a custom attribute or a more general one, such as NWB_ID.
  3. Add a Combo Overlay with the Height Map Overlay as input A, the Avg Overlay as input B, and with the formula: IF(GT(B, 0), SUB(A, 0.2), A).
  4. This Combo Overlay displays a height map with all roads 20 cm lower, and all other areas as they were.
  5. Now use the Combo overlay in Current Situation > Terrain > Select Elevation Grid Overlay to implement the change on the elevation model and visualisation.