Hello,
I used the PhotonGI cache with B.Y.O.B. settings (radius 0.01) but increased the max number of photons to 100 million. In the terminal, the indicated number of traced photons was 16 million. In the top reflection on the water, we can see the caustics, but on the pool wall, the caustics are less thin than with Bidir.
- PhotonGI cache, radius=0.01, max photons = 100M (Path+Sobol)
After that, I decreased the radius (0.001), the indicated number of traced photons was 30 million, and I seems that the image does not improve with the number of samples, it remains noisy. But the caustics are as thin as with Bidir.
Decreasing the radius to 0.0001 did not improve, the number of traced photons was less than with radius=0.001.
- PhotonGI cache, radius=0.001, max photons = 100M (Path+Sobol)
Also, I had to deactivate the indirect GI cache, as it seemed to skip the caustics cache creation (always the same message in the terminal indicating 6 million of photons).
For this image (for me it's the final), I mixed the water reflection for the PhotonGI / radius 0.01 image, and the Bidir image in Gimp to have this.
- Final image, top PhotonGI r=0.01 + bottom Bidir
Finally, having played with PhotonGI cache, I would have two feature requests:
- could we save the cache to reuse it without recalculating it, to play with the rendering engines settings for example ?
- could we select the object to target caustics ? In the swimming pool image, only the water surface has to be targeted, not the pool walls, which are big surfaces.