Rendering a 2D scene using spherical harmonics

Hi guys! :smiley:

This is my very first post on this forum! :smiley:

I would like to create a scene with an arbitrary object and render it using spherical harmonics, similar to what has been done here:
The code is quite large and thus, it’s hard to see through.

Does anyone have a suggestion on how/where to begin?

Thanks! :smiley: