It's much simpler than that: Both rasterisation and ray tracing are methods to solve visibility. The main difference is that one answers the question "given a p

It's much simpler than that: Both rasterisation and ray tracing are methods to solve visibility. The main difference is that one answers the question "given a primitive, what pixels does it overlap?", the other "given a pixel, what primitives does it overlap?" Light transport, shading, shadowing are all just implemented on top and not a direct result of the visibility calculation.