CrystalDome is an inexpensive alternative to a volumetric display based on video projector technology that supports omni-directional viewing (Figure 1). It can show mapped spherical surfaces, such as globes, and scenes composed of threedimensional objects. In the latter case, an algorithm was developed to perform hidden surface elimination in the hemisphere?s reference frame. Participants can sit around the hemisphere, which is built into a low table. Sensors capture hand movements near the hemisphere for adjustment of the position, orientation and size of the objects that are projected from below onto the inside of the display.