I tried now in Blender the new Light Tracing feature of Luxrender. This took with two 2070 only 1 minute, while the CPU, a really old i7 3770K took over the caustic calculations. 500 samples with OIDN.
My GAWD now there are insanely fast caustics and pools and ice and i could go on forever realistically possible
This is just one light and the caustics from the glass cube. IM SOLD! Not even Octane can do this sharp caustics with the PMC kernel, i totally tried.
If there would be a way to do light tracing in GPU, that would be insane, but as i read its bi-dir magic bound to CPU stuff. Still because the CPU does only the tracing part for the GPUs, it’s CRAZY fast. I for one, welcome our luxrender overlords
Even if there is a far zoom out the caustics stay bright and sharp to the horizon. Crazy…
Here with a higher exposure.