LuxCoreRender Forums

B.Y.O.B. wrote: ↑Mon Jan 21, 2019 10:22 am I think the need for this depends on how much trial and error is involved to find the right settings for the PhotonGI cache.
If you need a lot of trial and error, starting 10 renders or so until you found good setttings for photon count, radius etc., then it would be very good to have this pre-visualization.
On the other hand, if we manage to make this setting-finding process automatic or super fool proof, I think it would be ok to skip the pre-viz step.

Dade wrote: ↑Thu Jan 24, 2019 10:55 pm A fast update, tomorrow I will write an extensive explanation: I have the first working version with Metropolis photon tracing. This is the number of caustic photons created with a Random sampler while rendering Psor's cube:

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[LuxCore][0.780] Photon GI total caustic photon stored: 7600 (1000000 traced)

and this with Metropolis:

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[LuxCore][1.243] Photon GI total caustic photon stored: 172059 (1000000 traced)

In both cases I'm tracing 1000000 photons paths. So Metropolis is 172059 / 7600 = ~22.6 times better than Random sampler. In other word, Metropolis is ~22.6 times faster to fill the caustic photon cache ... quit good

The current Metropolis target function only account for filling the cache, the next step is to account for visibility too: photon will be shot where they are useful to fill the cache and can be seen.

lacilaci wrote: ↑Fri Jan 25, 2019 10:31 am Or can we build cache on cpu and then use the result with cpu brute force?

Dade wrote: ↑Fri Jan 25, 2019 10:51 am
Yes, it is also as DLSC already works and it is what I always do: all the pre-processing is done on the CPU and the result is used both for CPU and GPU rendering. Some stuff (like Metropolis doesn't really work well on GPUs) and it makes the development "cost" reasonable: I have to re-write the code only for the GPU rendering (the pre-procesing data are just transferred).