Lets make Lightmass EPIC (and understandable)

[Norman3D]

@Marlo

Can anybody help me what is the problem with my scene? I try a lot of things which in the topic too, but none of them solve my problem. Thanks for the help!

This is what is happening, it’s bug that isn’t fixed yet:

The black shadow in corners is due to too much biasing by Lightmass when tracing gather rays. With point and spot lights, only the first bounce uses a gather and is affected by this bug, while the rest of the bounces come from photon mapping which is not affected. With multibounce skylight, all bounces are gathers and are affected by this bug so the artifact is much more noticeable.

This is completely solvable but I just ran out of time for 4.18. It’s high on my priority list.

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