How it basically works, in one aspect, is the ray tracing reflections —> SSR transitions across the roughness spectrum of 0-1. So, the closer to 1 roughness a material is, the more it’s using SSR and not RTR. That’s from how I learned it so far, at least, in video / reading. However, I’m wondering if roughness value 1 is included in the function or if it’s specifically less than 1. IOW, is it RTR is applied up to and including 1, or is RTR applied at roughness values 0.999999… and lower? Since it has a gradient of SSR vs. RTR use according to how close to the threshold value it is, it’s probably not worth worrying about. I notice the RT spec=1 image is far more washed out than the path tracer. That’d seem to imply there’s extra diffuse lighting or a subtraction of color, which I think wouldn’t occur with SSR unless it was set up to do so.