Trying to join 2 trimmed surfaces


I’m trying to joint two untrimmed surfaces that meet at a trimmed edge. I can see that the corner where they meet is slightly off. Previously I have dealt with this by creating a new curve outline for one surface where this new curve outline does match up with the other surface, then adding some points or curves and patching or networksrf. For some reason, I’m not having any luck with this method with the attached file. I guess it is time to ask what is the best way to approach this?

SamTwoSurfaces.3dm(302.3 KB)

(Chris Kuether ) #2

Both those surfaces are really big [F10 points on]

I shrank both and still join wouldn’t work.

But joinedge works.

What are we building here?



Hi Sam,

CrvDeviation shows you where the surfaces are furthest apart, about 0.008 and your tolerance is 0.001. trying to join two patch surfaces like that is going to be nasty, Patch guarantees nothing about tolerances to input, I would trim off one or the other some distance and fill in with a more precise surface.


Does this work? Basically saved their edge curves and their intersect curve, untrimmed them and retrimmed using those curves, then joined. TwoSurfaces_nick.3dm(398.9 KB)


Thanks all, got it to work with your help. It’s part of a foot orthosis.

Thanks again!


Quick related question while I have your attention…

On a similar part, I have been able to joint the surfaces (using more networksrf than patch to get better accuracy), but they don’t form a closed polysurface, rather an open one. I’d like to be able to see where it is open rather than having to rebuild the whole thing to try again… any tips on how to quickly diagnose and solve the problem? See attached.

SamTryingToClosePolysurface.3dm(625.8 KB)


ShowEdges does that.


Brilliant! That could have saved me so much time, and will from now on!