Blendshapes freeze rendering under certain conditions [2018.3.0b8]

I’ve been working with blendshapes in the 2018.3 beta for a character creation system similar to what you expect to see in Bethesda games.
The problem is I’m unable to use the blendshapes on my hair models because it freezes all rendering, both in-game and Unity UI, see video.


  • This happens when the hair’s skinned mesh renderer has any blendshape values that aren’t zero (but sometimes it won’t happen)
  • The models and blendshapes work on their own, just not when in the same scene as the person
  • Freezes can be stopped by disabling either the hair SMR or all other SMRs (person and clothes)
  • The framerate is barely impacted and keeps running in the blind (& UI elements still work)
  • Reloading the exact same character will sometimes help and sometimes not
  • Disabling LOD will sometimes help and sometimes not

Any attempts to help will be greatly appreciated.

Found a workaround - baking the mesh with blendshapes applied. So after changing the blendshapes just add

        Mesh hairMesh = new Mesh();
        hair.skinnedMeshRenderer.sharedMesh = hairMesh;