That is what I'm proposing; use an integer representation in the CPU as the source of truth, then convert it to various floats as needed in the shaders, passed

That is what I'm proposing; use an integer representation in the CPU as the source of truth, then convert it to various floats as needed in the shaders, passed in as an argument to the shader on each frame. I haven't touched GPU code in a decade, but that's a reasonable thing to do on each frame isn't it? ``` float periodic_animation_sec = (now_ns % periodic_animation_period_ns) * 1e-9f; float fog_sec = now_ns / 1000000000; // or use a power of 2 ``` Regarding the acceptable level of approximation for human perception, I think my point still stands. My assumption is that the frequency content of fog is low enough that pixel colors won't change appreciably over the course of a second. Want 30Hz? That will give you a few days before the precision degrades. 10Hz? About a week or so. Or, find a different solution, like using the CPU to reset the state of the shader every so often. Figure out how to do that seamlessly, or just make sure there's an in-game sunny day every few hours.