Render VolumeSurfaceMaterial transparently at low intensity
Refactor face culling API in Materials.
Fork VolumeSurfaceMaterial into nascent VolumeMipMaterial.
Begin preparing for ray casting.
Refactor some BrainTileInfo methods into new BrainTileMesh class
Camera position in texture coordinates might be correctly passed to VolumeMipShader
Debug simplistic ray casting in Mip shader.
Begin experimenting with level-of-detail in GLSL, so I can sample ray correctly.
Clean up ray cast shader
Refining ray cast MIP shader.