interpolated cortical surface

It would be useful to have a cortical surface which is in between the white matter and pial surfaces. One way to generate a mesh would be to first generate a volume where each voxel's value reflects it's distance to pial surface minus distance to white surface perhaps normalised. Then, we could use an isosurface algorithm to extract intermediate surfaces between the white and pial surfaces.

Perhaps there are other algorithms in CGAL or maybe a way to continuously morph one surface into another.

Furthermore if we had some info on average position of different cortical layers then we could do true multilayer sims