4.17 VR Oculus stutter with Geometry Cache Alembic

Hello.

I realize Alembic’s Geometry Cache is in Experimental but thought i’d share some findings. This post also eludes to some general VR performance issue that i’ve found in this forum post related to 4.17: Forum post here

So, with Alembic’s Skeletal import, all works fine and good. With Geometry Cache - specifically with VARYING VERTEX COUNT, i’m seeing crazy stutter in Oculus Rift despite maintaining 90fps. NON-VARYING vertex count does not present the same issue. When I turn off Asynchronous Space Warp (Ctrl Numpad 1), AND set console command “vr.oculus.bUpdateOnRenderThread=0”, it significantly reduces stutter and in some cases completely removes it.

I’m not sure what is happening here, it doesn’t seem completely related to performance. Is it that varying vertex count geometry cache constantly changing the mesh per frame is messing with the Render thread?

thanks.

Just tested the very same Geometry Cache asset in 4.15 and there is absolutely no stutter. Supporting the possibility mentioned in the forum post that this may be related to 4.17 VR Oculus ASW/ATW performance. Or some ■■■■. xoxo