Project not projecting absolutely

Hi everyone, just a little problem that I can’t work out. I’ve got a few curves that I need to project onto a very large terrain surface that’s been made with the patch technique. I’m finding when I project there’s a small gap left between the surface and the projected curve, I’m guessing usually this gap would be negligible but because the surface is so large the gap is probably somewhere around a metre in the Z axis. Any help really appreciated

Post a file with the relevant geometry

that might have to do with the rendermesh setting. if you increase the density, unclean artefacts as curves not laying on a surface for instance vanish. it is basically just a display effect and will still intersect. to test use the command intersect.

that unfortunately is something which confuses many users not familiar that nurbs surfaces get displayed by a mesh. people get crazy rebuilding multiple times, all for a misunderstanding. i also fell into that trap a few times in the beginning.

Sorry for the delay it’s been a busy couple of days. It was the rendermesh as well, was sure I had checked that, anyway thank you for the help it’s reassuring that the file is good

A file example would be great. There are limitations to the math based on tolerance and distance from 0,0,0.

There are limitations in significant digits also. Usually not a big problem when moving dirt, but it becomes an issue as fabrication tolerances are needed on parts.

why would he do that?

I’ll upload a file this afternoon if that’d be helpful. I’m very sorry for the delay I’m not trying to offend anyone I’m just doing my architecture MA at the moment so I’m working on a few hours sleep a night and a to do list that quickly vanishes into triple figures

Again very sorry for the wait. The problem is largely solved now but I thought I’d upload an excerpt just in case it was needed for reference. Unfortunately trimming the model down makes the render mesh problem vanish but when the terrain is untrimmed the lines on the edge of the opening detach. Really appreciate all the help, thank you everyone
render mesh problem.3dm (343.9 KB)

Hello - use ShrinkTrimmedSrf before untrimming. Actually, in this case, ShrinkTrimmedSrfToEdge,


Brilliant thanks, Pascal