For example, after step 3 I realize there a structure I want removed from the DTM. If I add a surface to that area, it basically flattens it instead of editing the point cloud. I select the check box for it to be calculated into the DSM and grid, but there’s no DTM option. Re generating the DTM the elevation of the unwanted object is still there. Does the DTM not take into account any surfaces?
I think this maybe a bug. Just checked other surfaces created before step 3 and they’re all flat. May have to rerun the DSM before the DTM if you don’t want to redo all of step 3. It would be nice to get confirmation.
Hi Sue,
Thanks for your interest in Pix4D software solutions. If the point cloud classification is available, a terrain mask is computed based on the classified point groups. Only the Ground and Road Surface groups are preserved in the DTM. To improve the DTM, all the terrain points should be assigned to one of these point groups. To manually move points between the automatically generated point groups, the Edit Densified Point Cloud option can be used: 202560499. If the point cloud classification has not been generated, which is not recommended, all the points are treated as non-terrain points and the DTM is a smoothed version of the DSM.
Regards,
Aaron Woods