After messing around with outdoor lighting stuff for the first time, I came to realize just how little I understand about HDR. I get the basics: It simulates the opening and closing of the human iris during the transition between light and dark environments, and it does so mainly by producing a second, "overexposed" set of lightmaps that it can use in dark lighting situations, and that it also needs a corresponding set of cubemaps. But there's a lot I still don't get. Like, what do tonemap controllers really do, and why do different maps need different values for theirs? And is there ever any reason to set the BrightnessHDR and AmbientHDR in the light_environment to anything other than the defaults? And those cubemaps. Whenever I build HDR cubemaps it shows each angle going from full-overexposure down to the normal LDR levels. Is it actually committing every frame of that animation to the disk for some reason, or is there some other, weirder reason for it?