The red book say that you can use glNormal to break down a 20 sided object into more pieces thus making it more sphereicle. But i don’t really understand what glNormal does. U can only use it on vertices or vertex’s. But how do you calculate the normal at one vertex?..it’s just a point. They make a call like this:

glBegin (GL_TRIANGLES);

for (i = 0, i<20; i++) {

glNormal3fv(…);

glVertex3fv(…);

glNormal3fv(…);

glVertex3fv(…);

glNormal3fv(…);

glVertex3fv(…);

glEnd();

what exactly goes glNormal() do to those points?..thanx