LuxCoreRender Forums

Hi,
first of all, thank you for Luxrender. It is invaluable.

I'm experimenting with specular-diffuse-specular caustics with Path Tracing and PhotonGI Caustic Cache. After some search and tests (maybe not enough..) I'm still confused about the minimal configuration required to see caustics through mirrors; attached, a not-working example. Is there someone able to give a very basic list of to-do in order to have the SDS caustics working with PhotonGI Caustic Cache?

Thank you!
Igmar

Blender v2.83.3
LuxCore 2.4
Win 10 64bit

You have to make your twos cube renderable in the collection.
blend

The caustic cannot be seen in the 3D Viewport?

igmar75 wrote: ↑Mon Jul 27, 2020 3:21 pm The caustic cannot be seen in the 3D Viewport?

SDS caustic is generated by caustic cache.It is a cached solution. only light traced caustic can be seen in the viewport because they are not cached but directly computed.

All caches currently in LuxCore are only computed for final renders.
It does not really make sense to compute them in the viewport because they would need to be re-computed on every geometry or material change, and cache computation is usually too expensive for real-time feedback.

Thank you!
Igmar

1) I continued experimenting, and I found a possible cause of confusion: even if I leave checked the "Caustic Light Cache" file (under "Persistence"), it is not updated! To update it, I have to change the cache file name; unflagging and flagging again the checkbox will not work. Attached you can find the test file. I think you should try to reproduce this behaviour on your machine..

2) Moreover, I noticed that I have to put the Roughness (of the big cylinder) to a value >0.25 to have it collecting caustics. This is not in agreement with the Glossiness Thresholds, whose value is 0.05.

Any idea?