BUMPS (Brown University Multiple Projection System) is a program that illustrates the implementation of viewing transformations using animation. The program uses the viewing model defined in the Core Graphics System. BUMPS employs interactive computer graphics to demonstrate how planar geometric projections are generated, what the effects of different projections and projection parameters are on the projected object, and how the viewing functions of the Core Graphics System work. After presenting background material on projections, the features of BUMPS are described, followed by a pictorial user scenario of BUMPS in action. The paper concludes with a discussion of the merits of user controlled animation for teaching and possible improvements to the program.