02/04/2003
15-462 Graphics I
4
Lighting and Shading
•Approximate
physical reality
•Ray
tracing:
–Follow
light rays through a scene
–Accurate,
but expensive (off-line)
•Radiosity:
–Calculate
surface inter-reflection approximately
–Accurate,
especially interiors, but expensive (off-line)
•Phong Illumination model (this lecture):
–Approximate
only interaction light, surface, viewer
–Relatively
fast (on-line), supported in OpenGL