Ambient Occlusion AND Radiosity?

Ambient occlusion does an excellent job of creating well defined shadow areas and a pseudo-GI solution, but it does not take into account color contribution from surrounding objects. Using Blender’s radiosity method produces well saturated scenes with color bleed, but not accurate shadows. Can I combine the two? I’m curious if there’s a way to do this.

Here’s a simple cornell box style render with ambient occlusion and area shadows (creaes excellent penumbras!).

The full render uses a 16 sample raytraced area light with specular turned off and A.O. with 16 samples, but reduced energy. You can try the test scene for yourself with the original blend.

The problem comes when I try to use radiosity rendering first. By making any materials emit light, they become unshadowed, and if I use the full subdivision radiosity method, the materials are replaced by vertex lit ones.

Any ideas?


Calculating radiosity with an emitting material on a duplicate plane above the area light did the trick. It has to be very low power though, otherwise the area light overbrights everything, losing all shadow detail.

The effect is subtle, but the extra noise and definition in the shadows is a LOT better than default radiosity solutions. This should take some more tweaking, but I’m fairly happy with it as it is. Due to the higher number of polys produced for the radio mesh, rendering at full settings was a lot slower.

wow that looks really good. it looks like the ceiling could have used an extra subdivision though.

The update does look nice. Could you post a .blend?


Updated blend: