LuxCoreRender Forums

B.Y.O.B. wrote: Fri Sep 27, 2019 1:30 pm Are volumes supported yet by the modified cache? Wouldn't you need to store photons inside the 3D volume for it to work with the "orange juice scene"?

It works, but I have to use very high radius and low amount of photons to get it look good and also to have good performance. So I kinda have to decide if I want things like drinks to look good or if I want pool caustics to look good.

EDIT: Also open scenes have worse performance so I guess there is some issue there..

and since I would use higher radius the edges are kinda dark

I did some tests, and some caustics don't wanna show up with caustics cache.
(LuxCore version: https://dev.azure.com/LuxCoreRender/Lux ... uildId=801)

Light Tracing: Caustic Cache:
Settings:
I tried larger radius too, but it was the same except the more blur:

Btw., shouldn't the property be named "radiusreduction" instead of "rediusreduction"? (a instead of e)

provisory wrote: Fri Sep 27, 2019 2:06 pm I did some tests, and some caustics don't wanna show up with caustics cache.

Have you changed the photon path max. depth ? The default is something like 4...

lacilaci wrote: Fri Sep 27, 2019 1:53 pm It works, but I have to use very high radius and low amount of photons to get it look good and also to have good performance.

Filling a volume with cache entries requires a lot more work than a surface (i.e. 3D Vs 2D).

lacilaci wrote: Fri Sep 27, 2019 1:53 pm EDIT: Also open scenes have worse performance so I guess there is some issue there..

Shooting photons in the right direction in an open large scene from the sun is a lot harder than in a close small scene with an area light.

The visibility map (the place where cache entries are created), at the moment cover all visibile scene. If I use the cache only for SDS paths, I can use a visibility map of area seen trough only (nearly) specular surfaces (i.e. a lot smaller).

Dade wrote: Fri Sep 27, 2019 4:06 pm Have you changed the photon path max. depth ? The default is something like 4...

This was the solution, thanks!

Dade wrote: Fri Sep 27, 2019 10:00 am No, no, I will still add an option for "use_caustic_cache_only_for_SDS_paths" so you use PATHOCL + Hybrid rendering + SDS Caustic cache to get the best of all modes.

From the UI point of view it should be just a combo box in Blender with:

1) path tracing
2) path tracing + light tracing
3) path tracing + light tracing + SDS cache

I would not expose PhotonGI caustic cache at all in Blender, I would use it internally only if #3 is selected.

If "normal" and SDS caustics will be treated differently, won't be a hazard that they will look differently?
E.g. caustics in a mirror will be lower resolution than the original caustics in front of it.

provisory wrote: Fri Sep 27, 2019 5:03 pm If "normal" and SDS caustics will be treated differently, won't be a hazard that they will look differently?
E.g. caustics in a mirror will be lower resolution than the original caustics in front of it.

I doubt the difference will be noticeable in any real world scenario (and in vast majority of the tests).

Are you sure that caustic cache works with volumes?

It didn't seem to me in my scene, so I made a simple test case.

BiDir + metro: PT Sobol + Light Tracing: PT Sobol + Caustic Cache:

provisory wrote: Sun Sep 29, 2019 10:27 am Are you sure that caustic cache works with volumes?

It didn't seem to me in my scene, so I made a simple test case.

BiDir + metro:
CCvsVol-bidir.jpg

PT Sobol + Light Tracing:
CCvsVol-lt.jpg

PT Sobol + Caustic Cache:
CCvsVol-cc.jpg

I use homogenous volume with .1 scattering in my pool so I guess I wouldn't see much if it didn't work.

But I think theres some problem when there isn't much in the scene to bounce photons (hdri+a glass will render extremely slowly) that's why I suspected that photons might be shooting into infinity never being killed...?