03/26/2002
15-462 Graphics I
8
Ray Casting
•Simplest case of ray tracing
•Required as first step of recursive ray
tracing
•Basic ray-casting algorithm
–For each pixel (x,y) fire a ray from
COP through (x,y)
–For each ray & object calculate
closest intersection
–For closest intersection point p
•Calculate surface normal
•For each light source, calculate and
add contributions
•Critical operations
–Ray-surface intersections
–Illumination calculation