OwenWP: That is what we’re talking about, we’re on the unreal engine forums. The premise I’m trying to defeat is that all the examples of realtime caustics from Nvidia so far are path traced and accurate rather than artistic tricks.
Let’s be totally clear: the ray did not come from the camera, hit the water, become a caustic ray and hit the bridge. The path from the light source also didn’t hit the water and scatter a hundred new samples on to the bridge causing interference patterns. What happened is that someone wrote an emissive light texture function using the same function that the water is using to create waves. You can actually see the loss of detail in the expansion of the projection since whatever denoiser they’re using hasn’t been trained on that function. Classic sign of a procedural texture.
If Nvidia had real time caustics approaching path tracing quality they’d be waving it in our faces and calling it a unified solution rather than demoing shadows and reflections and caustics tricks.
I’m all for this generation of DXR enabled graphics, but let’s be realistic. We have the main three things we expected: reflections, shadows and first, maybe second bounce GI. Anything else is going to need to use machine learning. We should be extremely grateful that Epic is way ahead of the curve in giving us GI already as nobody else seems to have it figured out.