Index | Problem Statement | Polygonal Regions | Bounded Smooth Regions | The Three Dimensional Case |
Links to related topics | Glossary | References

## Glossary

Angle of Incidence: The angle that an incoming ray makes with the interior normal of the surface of relection.
In three dimension, the angle of incidence, the angle of reflection and the normal are co-planar.

Angle of Reflection: The angle that a reflected ray makes with the interior normal of the surface of relection.
In three dimension, the angle of incidence, the angle of reflection and the normal are co-planar.

Illuminated Region: Let G be a connected and bounded region. G is illuminated from a point p if for every point q that belong to G, there is a ray containing both p and q.

Directly Illuminated Region: Let G be a connected and bounded smooth region.  G is directly illuminated from a point p if for every point q that belong to G, there the line segment pq lies in G.

ray: Given a region G c R2.  A ray is a piecewise linear path with corners lying on a point p at the boundary of G respecting the usual law of reflection with the tangent line at p. Given a region H c R3, the ray behaves as in R2 with the tangent plane. Further, the incident and reflected portion of a ray are coplanar with the surface normal at p.

Smooth Region:  We define a smooth bounded region G c R2 such that the partial derivative of G has continuously turning tangent and G lies on one side of its boudary.

Index | Problem Statement | Polygonal Regions | Bounded Smooth Regions | The Three Dimensional Case |
Links to related topics | Glossary | References