benchmarks

loewe2

master
02:20.90

patch
02:19.19

volume emission

master
01.50.07

patch
01.44.82

zuggawood

master
01.43.24

patch
01.36.54

tonkinois

master
02.49.21

patch
02.47.39

head

master
03:53.58

patch
03.51.28

There's one missing crucial bit in this patch actually. The thing is, scene_intersect_volume_all() is not guaranteed to give intersections sorted by t. This could cause volume stack to be filled in the wrong order which depending on exact configuration of SSS/volume scene indeed could cause shading artifacts.

I've been trying to preserve isect array sorted by t in order to avoid calling qsort() but it ended up in some creepy code and it's probably simplier to use qsort. Number of intersections is not really huge, so there's chance expanded version of sorting will be used (similar to QBVH stack sort). That's easy to check tho.

In any case, i'd start with making sure intesrections are handled in proper order before looking further into SSS issues.

Pedantic: Don't use more tabs than on parent line when indenting wrapped lines ;)

/* Don't: */
<tab>some_long_function_name(bar,
<tab><tab><tab><tab>         thing);

/* Do: */
<tab>some_long_function_name(bar,
<tab>                        thing);

That will ensure good looking indentation in all editors.