-CollapseMeshFacesByEdgeLength not working


It seems both in V5 and V6 the hyphened version of CollapseMeshFacesByEdgeLength is not working.
(Also note the first run the edges are not selected I need to explicitily set the edgelength before anytrhing gets selected. Even when selected I need to change the view to force a redraw)

After an Enter:

Regular command:

Thanks Willem

Hi Willem - checking it, thanks.

Willem, this does work here so far in the latest - I’ll check earlier builds but it seems OK at the moment on my mesh sphere


Hey McNeel team,
“CollapseMeshFacesByEdgeLength” doesn’t work here in R6.6 [Rhino 6 SR6 2018-6-17 (6.6.18168.12081)] and R7 WIP. Can you please investigate?


Hi David - by ‘doesn’t work’ do you mean it does nothing or it does the wrong thing, or? Testing here it seems to work basically, so there must be more to it than what I see. Do you have an example file?


Hey Pascal,
after some experimenting here some observations I made:

“CollapseMeshFacesByEdgeLength” works in R5 with unwelded and welded meshes, but in R6 only with welded meshes. With unwelded or partially welded meshes in R6 you see mesh edges selected in yellow but nothing happens after hitting “collapse”. The reason the same model worked with this command in R5 but didn’t in R6 was because it was in STL format (where the mesh is unwelded) and during importing I didn’t took care about welding properly. Now after welding “CollapseMeshFacesByEdgeLength” in R6 works.
The result still has one non-manifold edge after collapsing edges shorter then 2mm, file attached.


bear_test.3dm (447.9 KB)

Hi David - I cannot repeat what you’re describing so far - here in the latest builds if I select your red, unwelded, bear and CollapseMeshFacesByEdgeLength I get a collapsed mesh as you show in your image above - no welding needed. Hyphenated (command line version) as well as the dialog version seem OK.

What service release are you running? (Help > About Rhinoceros)


Hey Pascal,

I’m running Version 6 SR7 (6.7.18177.12461, 06/26/2018), updated this morning.
I checked again and you are right, it works with a complete unwelded mesh but fails with a partially welded mesh, try attached.

Thanks for your help,

bear prtially welded.3dm (228.7 KB)

HI David - got it now, thanks.