this is the first release of the Irradiance Cache (IC from now on) for the photon mapping integrator. What it does, is to "remember" the value of irradiance at some points so it can interpolate it through the surfaces. This in theory save us time and in some cases can improve the quality of the render. There are two main parameters at the moment, Accuracy
and Max Samples
is inversely correlated to the radius of action of a given IC record (the point in the surface that saves the real value of the irradiance -the sum of all the incoming radiance-). So, the bigger the number, the more IC records will be generated, which means a more accurate interpolation. Max Samples
is the number of divisions that the sampling hemisphere will have along the "altitude" angle. The total number of samples per record will be Max Samples
*PI) (approx. 3*Max Samples
^2). The bigger the number the more samples per IC record will be taken.
So, both numbers will have a great impact into the final solution. The only problem is that the number of IC records can climb really fast, so I recommend to start with Accuracy
=1 and Max Samples
=10. If the image is too splotchy then you need a bigger Accuracy
(>3 is just a waste, so try to keep it between 1 and 3). Max Samples
should be kept between 10 and 25.
There are lots of ways to use IC with a PM integrator, right now I am using a very simple approach:IC records are created with just one bounce into the diffuse photon map, and the integrator just interpolates between the IC records for the diffuse component.
I want to warn you all that the code is being changed very often, and It haven't been optimized yet. IC tends to eat lots of memory (it can goes >1GB), so start small, every scene works differently.
You can find the sources at:http://github.com/Glaskows/YafaRayhttp://github.com/Glaskows/YafaRay_Blender-2.49
Last note, Final Gather
option must be on
.There is an issue with the forum right now, I can't upload any picture, sorry