I am trying to bake ambient occlusion to a texture using blender render on this model of a meteorite. It almost works, except for steep edges of holes, where I am getting a strange noisy / mottled pattern of black and white faces.
I did try using lightmap pack instead of spherical unwrapping, and it does make the mottled noisy areas go away. However, I need to use a spherical UV map shown because of requirements for scientific analysis later.
Can anyone explain what is causing this mottled pattern?