Regarding the holy grail point, I like to exagerrate and say that rasterization is based on glorified sprite rotoscalers. It is not used because it models how l

Regarding the holy grail point, I like to exagerrate and say that rasterization is based on glorified sprite rotoscalers. It is not used because it models how light works, it is used because it allows fast hardware implementations. On the software side, it's lots of hacks until it looks mostly believable.