Final Gathering at last ;)

Hi all !

Long time without news! I’m currently facing the most important time in a student life, its graduation,
that’s why I have posted previously that may-june will be a very busy time for me so I have near zero time to spend in my current projects, but zero coding is something simply impossible to ask to myself 😉
so to motivate me a little last nigth I open up blender source and review againg the so awaited Final Gathering
for the photon mapping algorithm, and this time with a fresh mind I could finally implement it.
The principal paremetter that now is added to the previously in the photon mapping build is final gather samples.
My previous development in the pathtracer was of big help because FG is in essence a hybrid algorithm of photon mapping and a pathtracer,
that’s why render times are longer that plaing photon mapping images but shorter than pure pathtraced images
(though nothing is absolut in this world 🙂

FG overcome many limitations of photon mapping at a price, it introduce high frecuency noise , only removed with many samples.

The essence of FG is very simple : firstly build the photon map in a preprocess stage, before the rendering actually begins and then at render time, when a shading samples is requested, instead of find illumination values in the photon map for a single value, many rays are traced in all hemispherical directions and then request illumination values at intersection points in the photon map and finally integrating all those samples.
(is a single bounce pathtracer of a photonmap)
Once the render internal of Blender get the benefits of faster raytracing many projects will get boosted at the same time like volumetrics and photon mapping so things may gett better in the future for all of us 🙂

There’s still many features that currently lacks the photon mapping build, like texture support and is very unstable and buggy for now, I will soon upload a new build with the Final Gathering in order to all of you toy with it. 🙂

Take a look at some test images, hope you will like them. with final gathering now is necesary in many cases to tonemap the images, I show here only the untonepapped ones.

Cheers to all Farsthary

PS: WOW! I have missed posting here 🙂

FG 8 OSA 100 FG samples Time 1min 59s

FG 8 OSA 100 FG samples Time 2min 4s

FG 8 OSA 200 FG samples Lamp samples 16 T 5min 33s

FG 100 OSA 8 Time 2min 16s

FG 100 OSA 8 Time 2min 56s

OSA 8 FG samples 100 Time 1min 46s

Time 2min 41s