Phong lighting is one of the most simple and intuitive methods for shading objects and it yields surprisingly good looking results (especially when you crank up the specular to 11 :P). The Phong lighting model is still to date a very popular lighting model used in games. The video shown here is an implementation of Phong lighting, used in three different light types: Point, Spot, and Directional. The spot lights are the most restrictive, as they attenuate by both distance and angle (only a cone of light is produced). The point light is less restrictive, but still typically attenuates by distance. The last of the lights is the directional, a point light assumed to be so far away that its rays are literally parallel with each other. The directional light is the simplest in terms of calculations as it does not attenuate at all, and it provides a simple way of emulating sunlight.