I have implemented two new materials. The first one is blend material, which adds a lot of power to the material system since you can arbitrarily use different materials on parts of the same mesh. The second material is two-sided material, which is useful for thin translucent materials like paper, lights, and leaves since it allows the back-face to receive light.
Below are three examples. The first one shows the blend material in action, the left sphere is a reflective sphere and the right is the blended material with a rough refractive material and the mask is the world map. The white parts receive 100% of material A and the black parts will receive 100% of material B, anything in-between receives a proportion of both.
For the two sided material the front facing parts relative to the camera receive material A while the back facing parts receive material B, and a flag for translucency to allow light to go through the back is optional and set as off by default. The second image shows a open cylinder with a two sided material. The third image shows an render with a spherical light place inside a tube, the interesting thing is that most of the light illuminating the scene is from indirect lighting.