- You can think of lighting as a way of automatically computing per-vertex
- Based on how geometry would look under a certain light source
- Pays attention to the normals to the surface. This means that to get
smooth shading, you must give a different normal for each vertex.
- "Shading" normals need not be true "geometric" normals - they are often an
average of the normals of adjacent triangles.
- OpenGL lighting is "local" - it considers only direct illumination,
not shadowing or interreflection of light
- To do lighting: set up a light source, set up materials, specify geometry