Maybe "Physically accurate Fresnel effect based on the complex IOR of the material" as the description?
Also, thinking about it some more, I'm not that happy with "F82 Approximation" as a UI name anymore, it seems too technical. I can't really come up with anything better though, so I'm open to…
Ah, yes, sorry - I misread the code, you're already doing what I suggested.
Actually it requires shifting the empty entry, but that's still better than all of them.
Inserting at the end is cheaper since it doesn't require any shifts, and should work just as well as far as I can see.
We could use the CPU's TSC for timing measurements. It might not be 100% exact on old hardware due to frequency scaling etc., but we could test for that using cpuid and being slightly off should…
Yeah, this seems like a safe thing to do, overestimating theta_e doesn't cause issues other than increased noise iirc and I can't find a simple expansion for atan(tan(x)*y) for x->pi/2.
A rendertime pass might be a useful way of exposing "what part of your scene is taking the longest to render".
I [hacked a render time pass](https://projects.blender.org/Alaska/blender/com…
I think this is intentional - if the view was applied to the color preview, then e.g. pure white for texture painting would be displayed as grey if a Filmic transform is selected.
The display…