The To Terrain tool will push survey items from their current elevation to the current terrain. The To Terrain tool only works on the selected items and appears in the Transform group of the TOOLS tab.
To Terrain works on:
To Terrain will force the Z values of the vertices to be adjusted to the terrain while maintaining their horizontal location. In the example below, only the selected polyline is pushed to the terrain.
The To Terrain operation will not add additional vertices to polylines or boundaries as the Densify tool does.
Update your survey
To Terrain is very useful when importing 3D CAD entities. If points were created from an earlier survey, the points will maintain their Z value when they are imported. You can use To Terrain to push the original survey to the new situation. In this way you can limit drawing new linework to the minimum and you have vertices on exactly the same position as in the original survey.
You often have check points available to validate your drone data. The To Terrain tool allows you to quickly extract the actual elevation from the terrain for those points.
- Import your check points (the PXYZD structure is recommended but not mandatory).
- Select your points and click To Terrain. This will change their elevation but will maintain their position.
- Export the points with Export Survey (to. csv).
- Compare the original and updated points in Excel.
Change vertical datum
It can happen that you have created your survey on an elevation terrain that was created at the ellipsoidal height (in the photogrammetry software) but your customer wants the survey in a local datum.
For this use case, To Terrain and Offset Within are the tools you need:
- Draw a boundary around your area and select the boundary.
- Then go to the TOOLS tab and offset the terrain first to the good vertical datum by applying an offset with Offset Within.
- Select your points, lines and boundaries and click To Terrain.
- Your survey is now aligned with the new vertical datum and you can export it again.