Please add Quick Caustics option also to standard VRay lights that are directional in nature (plane/disc), as a button we can enable per light source.
And make it possible to have multiple light sources create the Quick Caustics.
I fully expect the Quick Caustics to ignore the size/dimensions of any light source it is enabled on, and simply use the light’s direction as a guide for casting the caustics - similarly to how it works when used with a VRay Sunlight. Having this extra caustics option would be super, super useful.
Question: Right now the quick caustics are cast from a single sun light only, and when multiple sun lights are created, and some of them are disabled, vray will go through them in chronological creation order until it finds a sun light that is active and use that for the caustics. Is that how it works behind the scenes?
Question: Right now the quick caustics are cast from a single sun light only, and when multiple sun lights are created, and some of them are disabled, vray will go through them in chronological creation order until it finds a sun light that is active and use that for the caustics. Is that how it works behind the scenes?Something very similar, yes.
And make it possible to have multiple light sources create the Quick Caustics.
We can for sure add generation of caustics from multiple sun lights (see some WIP result in the attachment).
As for other light types, this is possible yes; will try to figure something out.
Can you shed some light (no pun intended) on how the quick sun caustics actually work?
As per other forum threads, and my own tests, they are very dependent upon polygon density - even when that extra density does not add visible detail to the geometry (like a box).
Light Cache is a lot slower when the qsun caustics are enabled. In a test where I only enabled/disabled qsun caustics, the difference in light cache prep went from 1min 8sec to 0min 6sec. Is it because they contribute to the spread of GI in the scene? If so, is this always needed? Please see my bottom comment about the render element.
If qsun caustics become available for other light sources, would it be possible to have the caustics spread at an angle based on light source settings? Eg. a plane light set to directional 1.0 would create a “parallel” direction, like the current sun mode, but any other number would spread the caustics out more, calculated from light source placement and directionality?
Attached is one of my tests, using a sphere and cube, with varying polygon counts. Same noise map are used as bump for both objects in all renders.
The two Caustics render elements at the bottom are from the 50k polygon example, but with some GI + sampling settings tweaked in the bottom right corner example. With those tweaks, this can become a very fast render pass for compositing the caustics.
