What he's referring to is a transfer function. The marching cubes are not just evaluated to find the surface where Voxel(xyz)=value But rather F(Voxel(xyz))=v

What he's referring to is a transfer function. The marching cubes are not just evaluated to find the surface where Voxel(xyz)=value But rather F(Voxel(xyz))=value What gets interesting is that both pre-interpolated, and post-interpolated versions are interesting.