I am having some issues with the reflection volumes (sphere or boxes) rendering wrong brightness on half-rough surfaces. It seems the energy conservation is broken.
At first I thought it was because I was using physically based light intensities, but noticed the same behavior with low unitless intensities.
Here is the problem I see: Screenspace Reflections is turned off, there is only a sphere reflection volume captured inside the room (brightness of 1). I am adjusting the roughness of the material from 0 to 1.
You can notice how the reflection becomes brighter than the environment when the roughness is around 0.25 - 0.3. In case you would be wondering, the sky above is not brighter than the visible sunrise, so there is no real reason for it to become brighter.
As a comparison, here is the same using screenspace reflections (max roughness of 1). You can see how the energy is more accurate as I change the roughness.
Another oddity is that if I turn the reflection volume brightness to 0, it still brightens the environment a lot. I need to turn off its visibility to make it not affect the environment. Is that the expected behavior?
Brightness 0 - Only a tad darker.
Finally, I noticed that overlapping reflection boxes would lead to darkening of the reflections. One volume doesn’t get priority over the other one, it just makes the overlap area darker.
I tried to reproduce these issues in the ContentExamples project but it seemed to work fine. I looked into my Project settings I tried turning on and off “Extend default luminance range in Auto Exposure settings” as this was one of the setting I had changed in my project. Otherwise everything is default. But this didn’t help.
Has anyone encountered the same problems?