Shading

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.

 
• Introduction
• Gouraud Shading
• Phong Shading