For those of you that follows the Mango project blog at mango.blender.org, yesterday a new feature has popped out from the work of Bretch, that is solving needs of the artists involved in the movie production.
This feature is the Blur Glossy, that seems to remove and clean caustic noise without visible loss of quality blurring it (I mentally associate this method with the common GI Final Gather blur)
Another thing that we realized was that Cycles sometimes problems with glossy samples at glancing angles, which lead to noise that doesn’t go away even with 1000 samples. But having Brecht at the institute it was just a matter of one hour or so until we had a fix for that: blurring glossy rays that hit sharp highlights. I don’t really understand how exactly it works internally, but: it works! Setting glossy blur to 1 helps to get rid of noise without any significant loss in quality.
This feature is also documented here:
as Blur Glossy:
When using a value higher than 0.0, this will blur glossy reflections after blurry bounces, to reduce noise at the cost of accuracy. 1.0 is a good starting value to tweak.
Some light paths have a low probability of being found while contributing much light to the pixel. As a result these light paths will be found in some pixels and not in others, causing fireflies. An example of such a difficult path might be a small light that is causing a small specular highlight on a sharp glossy material, which we are seeing through a rough glossy material. In fact in such a case we practically have a caustic.
With path tracing it is difficult to find the specular highlight, but if we increase the roughness on the material the highlight gets bigger and softer, and so easier to find. Often this blurring will be hardly noticeable, because we are seeing it through a blurry material anyway, but there are also cases where this will lead to a loss of detail in lighting.Whope to see that feature soon in the svn brunch
We hope to see that feature soon in the svn brunch