you can ray trace with pbr. Ray tracing is a technique to calculate the amount of light on a surface by projecting light rays from the camera (there are other r

you can ray trace with pbr. Ray tracing is a technique to calculate the amount of light on a surface by projecting light rays from the camera (there are other related techniques as well). Once you have the amount of light on a surface, you need to figure out the interaction of that surface with the light. Traditionally this was done with heuristic methods like phong shading. Pbr uses more physically plausible (and measurable!) heuristics.