Enabling physics on a skeletal mesh with per poly collision enabled crashes engine

[hGosling (Raskolnikow)]

Hi,

I encounter this bug for years now and wonder why this never got fixed. I want to use per poly collision on my character, but also want to set some parts of the mesh to simulate physics. I have set up a physics asset to do so. As soon as I try to apply physical animation or set bodies to simulate physics my game crashes:

This is really annoying and I found no ‘good’ way to fix this. The only workaround I found so far is adding another SkeletalMesh component for simulating phyiscs and use the CopyPose Node on the anim graph.

I can use functions like “GetClosestPointOnPhysicsAsset” without any problem and it even returns the bone name as it should. So I guess that the physics asset is working in game and can be queried …

UE Version: Every version… currently I am testing on 4.26

[Trandana (JC_Denton)]

Can confirm this is happening on my end too.

I wasn’t sure if this was a bug, or if simulating physics was incompatible with per poly collision on a skeletal mesh.

I don’t actually need physics collision on the mesh, I’m only using it for line traces, and using the physics asset’s simple colliders for collision.

It looks like the SkeletalMeshComponent->Bodies array is emptied when Per Poly Collision is enabled. Perhaps the engine assumes that you are going to use the polygons rather than the bodies, so empties it

[MostHost_LA]

Install debug symbols so your error message can be traced back.