I’m currently working on a project that requires ‘real-world’ lighting values and color captures that aren’t converted into a LDR color range; and for the most part Unreal has been a great help getting the lighting results I need. My current scene is an indoor scene using a single directional light with a power of 100 000 Lux and temperature values to closely follow real world lighting conditions; and relying on higher EV values to compensate for the more powerful (EV 8-12 is average) light values.
One of the strict requirements I have to follow is making sure tone-mapping and as much of the post-processing stack is disabled to not interfere with my final output. Because of this; I’ve noticed a visible color banding in the darker corners of my scenes that doesn’t look correct and is painfully noticeable. The banding is mitigated by enabling tone-mapping but this brings my color ranges out of HDR to match my display (if I’m understanding the theory right). I have an example here:
Note the grainy; yellow banding. Depending on my the exposure values and where direct light is happening the banding is more or less noticeable; but I can’t seem to get rid of it in a way that makes it virtually unnoticeable. I’ve also experimented with raising and lower resolutions on my walls but using a resolution of 2048 doesn’t seem to help.
I’ve tried decreasing light-mass scale and increasing quality as well as trying to compensate in my Indirect Lighting Smoothness but nothing helps. It also appears regardless of whether I’m using Static or Stationary lighting. In this particular example I also attempted to compensate with Diffuse Boost but changing this makes no difference. The settings I used in the above example for Light-mass are here; although I’ve gone as far as baking with scale 0.1; quality 10 with no luck:
Is there a known reason why this banding happens; and is there anything I can be doing to meet the requirements of this project and remove the banding? Anyone insight into this problem is appreciated.