Assertion failed: PointFaces[PointIndex].Num() >= 3 [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\SkeletalMeshComponentPhysics.cpp] [Line: 3181]

Good morning, i hope someone can help me with this issue… everytime i try to render a sequenz unreal crashes and i get this error message. the same happends when i try to simulate or use the play feature
Assertion failed: PointFaces[PointIndex].Num() >= 3 [File:D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\SkeletalMeshComponentPhysics.cpp] [Line: 3181]

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I also have this problem, I know how to solve this problem temporarily, but I don’t know why it is. If you want to solve this problem, just change the collision of objects to Add 10DOP or less. Not too high

@Online_Learner_zPnmz What does “Add 10DOP” means? I’m getting this crash too after trying out some assets. I find it happens when my character collides with those asset. Weird thing is it stop crashing after I disable clothes physics, but when I tried to enable it the crash returns, and no turning off clothes physics still crashes the game.

After a lot of experimentation I think I figured out the issue. I had a mesh with a corner (wall corner mesh, 90° angle) using auto convex collision. This kept making the editor crash when the cloth would come in contact with it. The simple fix was to manually add box colliders to replace the convex collision of the corner mesh. I also had some other meshes which caused issues such as those using complex as simple. When in doubt try simplifying complex collisions for simpler ones as the poster above mentioned, that fixed it. No more crashes.

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Same problem here. I consider it’s a bug related to collisions transferred from older Unreal Engine to UE5. I made some tests: mesh with “old” collision (looks like a simple box) crashes UE5, but if I redo collision (Auto Convex Collision) there are no more crashes.

I’ve created repo, if anyone is interested: GitHub - unreal79/ClothCrash-UE5: Cloth crashing Unreal Engine 5

(I think, I’ll report the bug.)

Just tested my old project in UE 5.4.2 – the bug is still here, UE5.4 still crashes on collision with cloth!

How to check if the auto convex collision is enable?

UE 5.4.3 – crash confirmed.

If possible, remove all collision, then replace with box or sphere. This solved the issue for me.

I have 300 static meshes. To circumvent the UE bug I have to replace collision boxes for all of them, and then test result (by crashing and restarting UE editor). Looks like a huge work…

Getting this too.

Tested my buggy project (see link above) in UE 5.5.2 – it still crashes.

BTW, my bug report was silently removed from UE bug-tracker. Sad.

Similar problem here. I isolated it to a single static mesh in my level (a flat piece of paper with 18 triangles), which I got from a marketplace asset. When a skeletal mesh with physics-based cloth was overlapping that mesh, it would crash every time on Simulate/Play/Render. A different Static Mesh - another piece of paper with the exact same Collision settings, right next to it in my level - did not cause a crash when overlapping the cloth.

When I opened the offending Static Mesh to inspect it, it did not have any special Collision settings compared to any of the other static meshes in the level. It had Collision Complexity set to Project Default (which was Simple and Complex) and had no Complex Collision Mesh nor Customized Collision. So the issue wasn’t directly related to those settings.

I changed it’s Collision Preset from BlockAll to NoCollision, which was fine for me since I didn’t care if a piece of paper had collisions enabled, and the crash went away.

So perhaps the Static Mesh itself had some collision data that breaks the newer code, or somehow was corrupt. Which could explain why the solutions above that involve regenerating collisions are effective.

Update: the method I mentioned in my previous post did work but it seemed I had to do this for random meshes in my world. Crashing was the only way to find an offending mesh, which was troublesome and time consuming.

Instead I opened the Skeletal Mesh that had the Clothing asset, and in the Clothing section I unchecked “Collide with Environment”.

This fixed the problem.

Of course the clothing no longer collides with world objects, which I can live with for my project.

Hope this helps someone!