We used a lot of render buffers on the project. Here are some examples until Will has time to do a proper breakdown and to correct my mistatements;).
Diffuse Shade
My understanding of diffuse shade is a buffer that shows the amouth of lighting hitting a particular pixel.
Incandesence
This buffer is based of the angle of the normal of a spot in reference to a particular point in space. In this case, the camera.
X Motion
Shows the horizontal translation data per pixel.
Y Motion
Shows the vertical translation data per pixel .
Ambient Occlusion
My favorite one, cause it look so cool. This caluclates where light is able to get into, darkening (when applied in post) those places.
Shadow
Pretty self explanatory, the shadows are the lighter values.
Special
We used the special buffer as poor man's object/surface ID. It was most useful in that we were able to assign the same values to different surfaces and completely customize the way we were breaking things up.
Specular Shading
Shows the specular values based on light input. I didn't use a lot of specularity, so not a lot is showing up.
Transparency
Shows only transparent objects, but was a great tool for making a mask of the eyes only.
Z Depth
Another cool buffer. Darker values are closer to the camera, lighter ones are far away. Used to simulate depth of field in post and I suppose adding depth fog if you wanted to do that as well.