Still curious how is environmental lighting in the different crystal balls are achieved? Seems very complicated considering each ball has different size, angle, etc.

How would the generated environmental lighting of something offscreen/out of image frame be represented? Are there assumptions that are generally applied or would some sort of hard-coding be required?

if lighting is precomputed would this change when the light source direction/strength changes?

I know Unity has multiple light sources and texture possibility, is it implemented using these techniques? What about other game engines?

How is lighting/shadows on a reflective surface such as the metal ball achieved? How do we know this placement of the lighting out of the scene and how exactly it hits the ball and reflects off?

I am also curious how the lighting on the ball can be done

What methods are used to precompute environment maps and how costly is it?

Thanks for the nightmares.