Hi guys!
I have a problem with water caustics. As you can see in the attachment there is so much noise on the building facade, but on the L-shaped plane in front of the rendering, the water caustics are clearly visible - noisy, but at least it is possible to see caustics drawing. In the background, on building facade there are just white, big noise dots which are unacceptable in final render
Some informations about scene:
sun&sky light
default render settings
basic water material + noise connected (bump) - screen in attachment
bacic coronaMTL on building facade - correct abledo value
I have tried everything. Noise connected to bump, displacement, creating 3d noise with basic water material (no bump mapping) without any good result. The L-shaped plane in front of the image is just for test - will be deleted anyway.
I think if you’d move the test plane to the same position where the building’s wall is, you would get the same result - too noisy caustics. The reason is the distance from the water surface. Caustics are not laser - with distance they get more blurry and probably at some point there is not enough photons emmited to converge to meaningful solution. I would try to play with caustics settings, but i can’t give you more specific advice here.
I don’t have Corona now, but IIRC when you enable caustics solver, there should appear caustics settings rollout in performance tab (or maybe you should enable it in dev/experimental rollout). Hopefully someone from support team will tune in and will guide you further.
Here are some experiments:
note1: I lowered the resolution but the improvement should be independent from that
note2: all images were rendered with 3 min time limit on a Ryzen 3900X
reset render settings (I only did it to have a “fresh start”) - render setup > scene > reset settings
enable caustics in the Performance tab
disable “Generate caustics from environment” in Performance tab - since we mostly care about the caustics from sun
set GI vs AA to 8 - caustics are calculated between each pass and lowering this allows more passes to be rendered within the given time = more caustics re-calculations
set light samples multiplier to 1 - this does not lower the quality in this case and makes rendering slightly faster
set Max sample intensity to 10 - again, small speed up and no visible bias
experimentally changed water material’s reflection and refraction glossiness to 0,99 - this makes the caustics a bit more smooth, but also blurs the refraction and makes reflections darker - optional
experimentally re-rendered in 07.07 V6 daily build - virtually no visual difference in this case
experimentally enabled development/experimental stuff rollout (https://coronarenderer.freshdesk.com/support/solutions/articles/12000021288) and increased the number of caustics max photon / iteration from the default 5 000 to 25 000 - note that this will always improve caustics quality, but will also make rendering globally slower and may cause running out of RAM
I am attaching an archive with all renders here. I hope that helps!
I hope there will be some good news!