We recently changed from Unity 2020.3.34 to 2022.2.5
In our project, we use a Global Volume with SSGI + Ray Tracing. We also use Exposure with a fixed value and a Visual Environment with Sky Type None and Ambient Mode Static. We have noticed a difference in lighting, but the scene and parameters are exactly the same as you can see in the attached images.
The HDRP Assets for 2020 and 2022 have the same configuration.
Or maybe is some parameter in the HDRP Asset configuration?
I tried with a new scene in both 2020 and 2022 and looks like the lighting behavior is different.
I’ve found the difference. SSGI works properly with Directional Lights, but fails with Area Lights.
Indirect lighting is not being calculated with Area Lighs.
This is expected, it’s because the denoiser doesn’t affect smooth surfaces by default when bounce count is 1. When it gets above, we can’t really know if the reflection inside the reflections is going to need denoiser or not, so we denoise even smooth surfaces which result is a slightly blurrier smooth surface (and you are right that this depends on the radius of the denoiser as well).