03/14/2002
15-462 Graphics I
32
Environment Mapping
•Allows for world to be reflected on an
object without
modeling
the physics
•Map
the world surrounding an object onto a cube
•Project
that cube onto the object
•During
the shading calculation:
–Bounce a ray from the
viewer off the object (at point P)
–Intersect the ray with
the environment map (the cube), at point E
–Get the environment map’s color at E and illuminate P as if there were a virtual light source at position E
–You see an image of
the environment reflected on shiny surfaces
