That’s because in the “use full texture” mode, the RSM texture size is low, and when the sphere is visible from the light, it takes a sizeable amount in the flux texture and bounces light all over the place.
As explained in the doc, the “use full texture” mode is probably more adapted to static scenes, where you can tweak parametes for a single configuration.
Currently, adjusting the RSM texture size and intensity can improve overexposure but not eliminate it entirely. However, achieving the effect of illuminating the entire room like this is difficult without using full-texture mode.
If you don’t move the object, you should be able to tweak the parameters (intensity, …) to achieve what you want. Else, maybe don’t use the “full texture” mode but add another light in the room to spread the GI effect?
Without enabling full texture mode, adding two spotlights in different directions to the scene doesn’t come close to achieving the effect seen in full texture mode
This PR adds a parameter (use32BitsDepthBuffer) to enable 32 bits depth buffer: