RTXDI + Groom crashing

Hey all,

I’m currently working on a UE5 project and we have decided to switch over to the NvRTX build compiled from source to take advantage of the ray tracing performance increases (particularly when used with an RTX 4090). Very happy in that regard!

However there are some issues I’m running into and the first major one I’m looking for help with is the engine crashing when RTXDI is enabled and I have a groom asset visible.

Here is the error I’m getting:
Assertion failed: Buffer-> Desc.UnderlyingType != FRDGBufferDesc::EUnderlyingType:VertexBuffer [File:F:\nvrtx\UnrealEngine\ Engine\ Source \Runtime RenderCore PubliciR enderGraphResources.in] [Line: 193] VertexBuffer Hair. VisibilityNodeCoord requires a type when creating a SRV.

I’ve tried the following combinations:
Groom ray tracing enabled/disabled + RTXDI disabled = works
Groom ray tracing enabled/disabled + RTXDI enabled = crashes

I’ve also tried the combinations above with the cvar
r.RayTracing.SampledLighting.Hair 1
and get the same crash.

At the moment the workaround is that I’m just not using RTXDI but would very much like to enable it!!

Any help would be much apricated, thanks!
John

For reference, I’m able to replicate this bug by opening up the RTXDI sample project and importing a metahuman, same error resulting in a crash.