This test was taken from Processing.org which tests to make
sure the spotLights() works correctly on a sphere.
// Test from Processing.org
size(100, 100, P3D);
background(0);
noStroke();
background(0);
spotLight(51, 102, 126, 50, 50, 200,
0, 0, -1, PI/3, 400.0 );
translate(80, 50, 0);
sphere(30);