Final Gathering Follow-Up
Thought I'd start up a topic following up on some of the issues left open from our meeting on Final Gathering.
Eventually, I hope to put the presentation up on the web, but I need to make some changes, add more pictures in the light paths section,....
I'll back up just a little so others listening in can catch on.
Finalgathering in 3.4 allows diffuse secondary FG rays.
The primary FG rays are the ones shot out in the hemisphere above the FG point. Wherever they hit, the material may spawn a secondary FG ray.
The finalgather trace depth option, specifies how many secondary rays of each type are shot. In 3.4, there are now four arguments:
finalgather trace depth reflect refract diffuse total
[BTW, from the command line in standalone, you leave out the word trace, and it becomes:
-finalgather_depth reflect refract diffuse total
finalgather trace depth 0 0 0 0
is the simplest form of finalgathering. No secondary rays are shot.
At the material where the primary FG ray hits, only direct diffuse and ambient, and whatever doesn't require a ray is collected.
If we add, the ability to do a single reflection wherever that primary FG ray hits a material, we specify:
finalgather trace depth 1 0 0 1
For a single refraction:
finalgather trace depth 0 1 0 1
Now a diffuse reflection counts in two categories, reflection and diffuse, as well as the total. So, for a single diffuse reflection
finalgather trace depth 1 0 1 1
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