Physics related crashing

Hi everyone,

There’s a sphere that has been making the game crash in certain locations. It doesn’t make sense to me because it happens on flat surfaces usually.

A few details that may be helpful:

  • The sphere is using CCD
  • There are hit events for this sphere
  • The meshes it interacts with are using complex collision as simple (rolls on these meshes)
  • It has worked before without any issues on a different map (with the exception of crashing the game in 1 location)
  • I can’t pick out anything unique about these locations where it’s crashing
  • The crashes only seem to happen when the sphere touches a mesh it doesn’t like in a spot it doesn’t like

I’m thinking it might have to to with the hit events? Maybe too many (is that possible)? I can’t figure out what’s wrong by looking at the crash log although my experience in this area is minimal. No idea what it could be, just hoping something isn’t corrupt or it may even be a bug… This was an issue for me in 4.17 as well. It’s been plaguing my mind for months and I can’t figure it out.

Thanks

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Hi Isaac,

Are you attempting to simulate physics on meshes that are using Complex As Simple? I suggest creating custom collision for all meshes that are simulating physics. Using Complex As Simple isn’t performant and can cause issues.

PIE: Warning: Trying to simulate physics on
‘’/Game/VirtualRealityBP/Maps/IslandMap.IslandMap:PersistentLevel.MGCmesh_MGCmesh__325590__1.StaticMeshComponent0’’
but it has ComplexAsSimple collision.

As for the crash, could you provide your full Crash Callstack including your EpicID and MachineID? Please make sure to submit this callstack window so we have in logged in our tracking system.

Any screenshots of your setup, repro steps, or a test project could also help as well.

Hi TJ, thanks for responding.

“Are you attempting to simulate physics on meshes that are using Complex As Simple? I suggest creating custom collision for all meshes that are simulating physics. Using Complex As Simple isn’t performant and can cause issues.”

The sphere is simulating physics (& CCD) with default collision. The static meshes that it is interacting with have complex collision as simple and are not simulating physics. I’ve included a screenshot of the sphere and mesh surface from above in wire frame (to see the simplicity of the mesh). I’m beginning to think that it might be related to velocities getting updated in the blueprint via a timer and will try remaking the sphere blueprint with and without these timed velocity updates.

“As for the crash, could you provide your full Crash Callstack including your EpicID and MachineID? Please make sure to submit this callstack window so we have in logged in our tracking system.”

I submitted the complete report through the editor prompt recently when I reproduced the crash.

Thanks

So after disabling these velocity changes set on a timer, the crashing has stopped. I have found an alternative way to achieve what I wanted in the blueprint but for now, it seems like that was probably bogging down the performance. I’m no expert but it seems to have been the issue.

Appreciate the help though, TJ.