Neat project! I'm not sure if the author is familiar with ambient occlusion, but the method described here can be extended to generate ambient occlusion data w

Neat project! I'm not sure if the author is familiar with ambient occlusion, but the method described here can be extended to generate ambient occlusion data which helps with a couple flaws. In particular: - Although the shading is very nice (see Figure 8), the long shadow rays are distracting and are not very useful for cartography. Ambient occlusion extends the idea presented here, except that instead of sending rays towards a relatively small light source, consider the light source to be the entire hemisphere of the sky, like on an overcast day. The result is wonderfully soft light that conveys form much like Figure 8, but without shadows. Simply send out more rays to the entire sky hemisphere to create this effect.