The term ray tracing refers to any algorithm that follows beams of light to determine with which objects they interact in the world. Applications include light map generation, visibility determination, collision detection, and line-of-sight testing. This chapter describes how the points of intersection where a ray strikes an object can be found and how to alter the path of a ray when it strikes a reflective or refractive surface.
The problem of finding the points at which a line defined by the equation
intersects a surface generally requires finding the roots of a degree n polynomial in t. For planar ...