Diver and Alice: An Immersive, Virtual Environment, 3D Graphics System

Back in the 1990's, the University of Virginia, under Randy Pausch, acquired two 100,000.00 SGIs to create virtual environments. We used magnetic polhemus trackers to know where your head and hands were and a very heavy head mounted display. The lenses had to sit so far out front that a sandbag was mounted on the back to counter-balance the gear. I wrote DIVER (DIstributed Virtual Environment Rendering system) in C, based on early versions of openGL. Since we used two sgis, one for each eye, It used udp sockets to communicate updates the the scene graph and syncs for rendering. DIVER departed from the Inventor scene graph with its own model, allowing any object to dynamically reparent under any other object without suddenly jumping in space due to the newly inherited parent matrices. DIVER supported the idea of multiple cameras, of a rendering loop that was independent of a scene update loop, and the development of a simpler API with calls like object.moveTo() rather than matrix updates. We then put different, interpretive programming languages on top of DIVER to allow rapid prototyping without needing to know C or to recompile and restart the system. Python was the prefered language at the time and developers could work at remote stations and send the rendering commands over to DIVER. In addition to developing new models for virtual environments and creating a virtual environment based perception lab, we also developed Alice to help people learn how to program in 3D. Alice has come a long way since then and has undergone many re-writes and programming language changes, but even twenty years later, with the occulus rift, we are seeing folks re-invent and relearn some of the benefits and problems that an immersive headset creates.

Videos

UVa early VR video (various time-critical rendering techniques and separation of simulation from human movement) Alice: Worlds In Minature (Richard Stoakley genius) updated with Portal sounds UVa early VR video 01 UVa early VR video 02 UVa early VR Pool Table Level-of-Detail control

Papers