it has now become treacherously noticeable how slowly volumetrics renders with the Inside Volume mode.
You used this mode in the "sphere" example, right? I can only recommend increasing the step size as much as possible and enabling "single bounce only".
(and of course the ability to render caustics by region)
This should now work better than before. If you render a region, this should not result in glitches/splotches, but under the hood caustics are calculated for the whole image, so there won't be as much speed up as expected.
Throwing one more. :)
Yes, where the smoke above the surface is not uniform, which is usually the case in scenes closer to production. I even had to do this pic with a step size of 25 cm and render it in a very low resolution, I'm afraid to imagine what will happen in a real exterior scene, for example, like yours with the pool.
I recently had scenes with a hot jacuzzi, where I would like to get caustics from a light source at its bottom, passing through a layer of bubbling water and steam above it. Naturally, this will be the noisiest place in the whole scene and I would definitely use a render region after the rest of the scene is ready. But, according to my tests, rendering with a region still creates splotches for now, which then do not disappear later.
