As described in the above image, when I enabled both hardware ray-traced shadow and nanite geometry collection, the shadow disappeared. The nanite geometry only accepts direct lighting from sunlight and point light, without AO and shadow.
Here’s another example of this.
I viewed Unreal Engine source code and found that this issue was caused by FNaniteGeometryCollectionSceneProxy in Engine/Source/Runtime/Experimental/GeometryCollectionEngine/Private/GeometryCollection/GeometryCollectionSceneProxy.h.
This class doesn’t override this function in base class:
void GetDynamicRayTracingInstances(FRayTracingMaterialGatheringContext& Context, TArray<struct FRayTracingInstance>& OutRayTracingInstances) override;
So when ray tracer tries to get the instances of geometry collection, it returns nothing. I found that the latest git commit was in June 2023, and engine developers left a todo comment on FGeometryCollectionSceneProxy, not the nanite one.
Is there any further plan to fix this issue?