Jim says: I have verified the culprit is either the tonemapper itself or one of the functions connected to it. Per Martin’s direction, I turned off tonemapping and got hugely improved results even in the default scene. See the following images.
First image is with tonemapping enabled. Second image is tonemapping off.
When turning on tonemapping, the highlight on the table becomes grey instead of white. All the whites in general are lost and become grey. This means not only is their an overall loss of contrast, but the white point is incorrect.
The colors get desaturated reducing vibrance and depth.
This is a fundamental problem that needs to be addressed. Some people could make an argument that it results in a better mapped image – but in reality it’s less physically-accurate AND prevents the artist from getting extremely hot highlights and vibrant saturated colors. It really isn’t beneficial in any way. The only seeming positive effect is that shadows get richer, but richer shadows should be setup properly with lighting adjustments, texture changes, or a simple post process color curve that only effects mid and dark tones. The tonemapper should not be responsible for darkening shadows.
I took a look in the PostProcessTonemap.usf file and found the line that calls the tonemapping function as well as the color grading function. I tried bypassing both of them and for some reason the tonemapper still takes effect. Could someone direct me on specifically what to change in the shader file to disable the tonemapper completely? I don’t know why my edits aren’t taking effect.