Question

I’ve read the codes in the redbook about drawing a sphere, but it is a unit sphere with radius=1. It starts from a icosahedron, an x and a z are defined to make the distances between all the 12 vertices and the center equal 1. So what if I need a larger or smaller sphere? I changed x and z proportionally, but it didn’t work. How should I set the values of x and z to get a smaller sphere?

Answer 1

Apply scaling transform before drawing the sphere. If you are using fixed functionality pipeline you can do it using glScalef(...). Otherwise you will have to construct the scaling matrix yourself.