[hnuser123456]

I get the impression the goal is to save 3D environments with baked lighting without having to run raytracing, at a level above explicitly defined meshes with faces covered by 2D textures, which can't represent fog, translucency, reflection glints, etc without a separate lighting pass. Basically trying to get raytracing without doing raytracing.

[kridsdale1]

I would say they’re an attempt to extend the concept of a photograph in to truly 3 dimensions (not a 2D bitmap with a depth layer)