1. experiment with the OpenGL lighting model lightlab lets you set the colours and positions of several light sources, and then watch the effect that it has on a simple 3D scene. You can select whether the scene contains a rotating cube, sphere, or teapot, and whether that object has a texture image on its surface. lightlab is not a modelling program; it doesn't even let you save anything. But if you're having trouble wrapping your brain around the various parameters you can set in OpenGL code, you may find it helpful. From Debian 3.0r0 APT