When attempting to Create Clothing Asset from Section on a mesh with a clearly selected section I get the error:
**Failed to generate clothing sim mesh due to degenerate triangle, found conincident vertices in triangle A=X=0.742 Y=-22.883 Z=148.878 B=X=0.962 Y=-23.335 Z=150.640 C=X=0.962 Y=-23.335 Z=150.640
**I have a vague idea of what this could mean, but can anyone assist me with first correcting the problem and secondly giving me enough information so I don’t make it happen again?
Hey, I know I’m a bit late, but try changing (in the APEX export settings) the output unit to centimeters instead of meters. We noticed in the .xml files that correspond to the .apx files that are exported from the scene, the *ContactOffset *value was really, really low. Once we changed the output unit, the *ContactOffset *value became larger and we no longer saw the error in Unreal. My theory is that the export size was so small, that the engine interpreted the distance between vertices small enough to call them coincident.
I have encountered this as well, there is a typo in the error “conincident” should be coincident vertices, which means vertices occupying the same space withing some tolerance. It appears that distance tolerance is around 0.06 or less.
Thought I’d leave a more concise answer, for anyone experiencing this problem (as I was):
Remove Doubles has been replaced with the “merge by distance” function in Blender. It’s now located in Edit mode, under Mesh > Merge > Merge by distance. You want to be sure to increase the distance from the default value of 0.0001 to something higher if you get the message “0 vertices merged”. For me, I increased the distance to 0.01 until I got the message “3 vertices merged”, at which point I was able to reimport the clothing mesh, and create the cloth physics data.
I have the same issue, but with the new Panel Cloth in 5.4.
Now the first I did was exactly what was proposed. I went to blender and started “Merging by Distance”. When I used the defailt 0.0001 value, I got nothing. So I increased the threshold to a staggering 0.05 m where in fact 5000 vertices were killed. And still I get the same error in Unreal…
Something must be wrong. Either the the mesh data is incorrectly stored and gives the impression that the vertices are coincident, while in fact they are not or something else maybe some unit conversion issue.
It cannot be that vertices must not be closer than 5 cms (!) to each other for Cloth to work.
OK, I have continued my investigation, and I think this is a bug in UE related to how mesh data gets handled either by the Panel Cloth editor or the Unreal mesh editing tools.
I found another of my models that was pretty small and gave only one “coincident vertices” error. I opened it in Blender (could not merge any vertices by distance again) and looked for the triangle with the vertex numbers 610, 612, 607 that is supposedly with coincident vertices, which leads to a failure when generating the skinning data. And guess what! There is no such triangle in the entire mesh.
Attached is a screenshot from some two of the three vertices I found, namely 607, 610 but they are not connected to 612 which is much further downstream in the topology. The triangle referenced in the UE error output simply does not exist. You can see in the screen all the neighboring triangles.
I’m having the same issue and noticed a very weird behavior.
Duplicated vertices is definitely not causing it for me and merging vertices in Blender doesn’t help.
Initially my skirt from Marvelous Designer has these materials assigned:
When I leave everything like it is, applying cloth data in UE works.
I noticed that when I delete all these materials and just create one, because I only need one for Substance Painter, then I get the degenerate triangle error.
I don’t get it. If I leave the initial materials apply cloth data works. And the mesh has over 2000 duplicated vertices.
Did you merge any objects inside Unreal? Like in my case the cloth consisted of multiple parts which I however merged together.
one cloth that I did not merge inside the engine, does not have this problem.
The reason I suspect this may be related to merging is that when you merge meshes, the vertices get new index positions (obviously because cannot have the same ID number), and if this merged data is somehow corrupt this could lead to a false detection of coincident vertices. But this is just my hypothesis, my 2 cents basically
No, I did not merge anything in UE.
I am using the new cloth asset workflow now, this also gives me the degenerate triangle error, but it still works as I am not using the skinning nodes, as my skirt is already skinned.
What got it working for me without exporting it to blender was going to the mesh and inside of the asset details I lowered the triangle percentage. Might be a bit of a crazy work around but it worked
Chiming in again to say I am having the same issue with panel cloth assets, “Merge by distance” in Blender doesn’t fix.
Oddly, despite the warnings the cloth asset does appear to simulate in both the panel cloth preview window and in-game, and to me it looks fine. So, one option might be to simply ignore it if you can and wait for more info or a proper solution.
Reducing the “Percent of triangles” in the skeletal mesh asset details panel as @IDirtystylez1 suggested did work for me. I reduced the triangle percentage by 0.1 until all the warnings went away. This requires pressing “Apply changes” and refreshing the skeletal mesh import node in the cloth asset graph in between attempts until you stop getting warnings. The percent that ultimately worked for me was 0.8.
I would think other mesh reduction tools offered by the editor would also work for this, such as the “Simplify” or “Remesh” operations provided by the skeletal mesh editing tools plugin. These operations didn’t seem easily undoable like the “percent of triangles” method is though so definitely duplicate your assets before attempting them.
I had this same problem when trying to import a mesh that was really tiny and then creating cloth on that skeletal mesh didn’t work and produced this error. The fix was quite easier than expected. I took the mesh into Maya (or Blender) and scaled it up then exported it. The error was no longer there.
Some previous replies mentioned similar fixes. I think the idea as to why this was happening is because Unreal is computing the vertices as too close together since the mesh was so tiny. If you have duplicate vertices or faces on top of each other in the mesh that are unintended, you may want to merge threshold all vertices with a value of like .001. This will get rid of any vertices that aren’t intended and will probably fix this issue if the scale thing wasn’t working.
