I have 2 triangles and I’m rotating them. It seemed as if the lightsource didn’t rotate with them, so I rotated it explicitly, but still it looks weird. The upper triangle brightens up just before turning backward.
Here’s a video about it: http://www.youtube.com/watch?v=Dgc0k_hUcIY
The code I tried:
void update(){
glMatrixMode(GL_MODELVIEW);
glLoadIdentity(); //Reset the camera
gluLookAt
(sin(angle)*3,cos(angle)*3,0.4,
0.0,0.0,0.0,
0.0,0.0,1.0);
GLfloat lightPos0[] = {sin(angle+80.0), cos(angle+80.0), 0.1f, 1.0f};
glLightfv(GL_LIGHT0, GL_POSITION, lightPos0);
angle = angle + 0.03;
glutPostRedisplay();
}