Sounds like the first thing you are describing is closer to ray casting. Ray tracing doesn't have the limitations you mention. Roughly speaking, ray tra in tec

Sounds like the first thing you are describing is closer to ray casting. Ray tracing doesn't have the limitations you mention. Roughly speaking, ray tra in techniques are variations on the concept of tracing a ray from the camera back into the screen and seeing where is ends up. The different variations distinguish themselves by what happens at a ray intersection. Classical ray tracing will spawn a shadow ray towards light source. Path tracing will stochastically sample some distribution of ray directions (usually based on a combination of light locations and material properties) in order to do Monte Carlo integration of the rendering equation. There are other variations. Ray tracing (w/ only shadow rays) doesn't give you global illumination. Path tracing (this work) does.