Shading algorithms apply lighting models to polygons, through interpolation from the vertices.

**Flat Shading:**- Perform lighting calculation once, and shade entire polygon one colour.
**Gouraud Shading:**- Lighting is only computed at the vertices, and the colours are interpolated across the (convex) polygon.
**Phong Shading:**- A normal is specified at each vertex,
and this normal is interpolated across the polygon. At each pixel,
a lighting model is calcuated.

Readings: Red book, 14.2;
White book, 16.2.4, 16.2.5;
Hearn and Baker, 14.5.

CS488/688: Introduction to Interactive Computer Graphics

University of Waterloo

Computer Graphics Lab