I’ve been testing hair grooms and path tracing in Unreal 5.0.2/5.1, and noticed that there’s a big performance drop in FPS once the groom is either bound to a skeletal mesh or a groom cache is used. I also noticed that trying to bind a groom to an alembic cache causes an outright crash.
When the groom is not bound, the path tracing is almost instantaneous. The performance drop doesn’t seem to happen in Lit mode, only in Path Tracing. Here are some tests on a simple sphere:
I was wondering if there are any more settings I can try out to lessen the performance impact?
I was actually wondering if Epic is aware of this issue, because I’ve tried a good amount of things systematically, and none of them improved the performance. I’ve built a few different UE versions off of github, used multiple ways to get an animated groom, and tried quite a few console commands as well.
Its interesting because UE has a really fast path tracer, but groom binding/groom cache just seems to tank performance.
