HDRP - Raytraced GI denoising issue with skinned motion vectors

[noam_2000]

When using Ray Tracing with Screen Space Global Illumination, Skinned Mesh Renderers with “Skinned Motion Vectors” enabled will flicker and jitter, as if denoising is failing on them. This behavior is only observable from a camera in the game view, scene view does not have this issue.

• Unity 2022.3.48f
• HDRP 14.0.11

Repro project: Dropbox

Steps to reproduce:

1. Start an HDRP project with the aforementioned versions.
2. In the HDRP asset, make sure you have “Realtime Raytracing” enabled, and “Screen Space Global Illumination” enabled.
3. Add a Screen Space Global Illumination override to your scene volume, and set tracing to Ray Tracing.
4. Add an emissive object and place it next to a skinned mesh renderer.
5. Add a camera.
6. Observe how the screen space lighting on the mesh jitters around from the game view. This is fixable by disabling “Skinned Motion Vectors” on the mesh renderer.

(on the left: skinned mesh renderer. on the right: static mesh renderer)

[chap-unity]

hey, In the advanced setting of the SSGI (the three dots on the top right of the override > show additionnal properties), have you tried to un-check receiver motion rejection ?

[noam_2000]

Ah, that did it! Thank you!