I have been using the drape command to create a surface over meshes made from ASCII DEM files exported from QGIS using Florian Frank’s DMT for Grasshopper. Everything works well until I go to trim the draped surface, which causes the surface to badly distort and loose definition. I have searched for a solution to no avail, and have tried various tactic such as moving the surface, scaling the surface, changing the units the model, but nothing seems to help.
Hello - setting a custom display mesh for the object does work, but my suggested tolerance was too large, I got the scale wrong from the images - use 0.1 or there-abouts as the ‘Max distance edge to surface’ - you may also want to fine tune that and other settings as outlined here: https://wiki.mcneel.com/rhino/meshfaq
Why it goes so wrong after trimming, I am not sure yet. Note you can also ShrinkTrimmedSrfToEdge and it will clean up as well - basically makes it untrimmed again, only smaller.
Wow. I first tired you 0.1 value which, to my great satisfaction, worked perfectly. Then I ran the ShrinkTrimmedSrfToEdge to see if there was further improvement, but it looked much the same, visually at least. Then I tried the ShrinkTrimmedSrfToEdge on a previous trim that appeared distorted and that too, on its own, worked perfectly, again, at least visually. Unless you think visual inspection inferior to some kind of real analysis, I would just say thank you for your help!
