Supplying Normals for an Icosahedron Tutorial - OpenGL Tutorials in Delphi

  Here we draw the same 20 sided sphere, but now we add normals to it.

A normal, in short, defines the direction a specific polygon or vertex is pointing. It is used often when working with Lighting.

We also use GL_LIGHTING for the first time.
Do not worry about this for the moment, it will be explained in a later chapter.