In 1999-2000 Clearwater Software was contracted by The National Institute of Standards and Technology (NIST) Intelligent Systems Division to develop CAVEWeld, a Virtual Reality application designed to enable users in remote locations to collaboratively operate a welding robot.
This project demonstrated interaction between real-world systems and fully-immersive interactive virtual words. Participants were able to see, hear and control the operation of a real-world welding robot through their interactions in the virtual world.
CAVEWeld was demonstrated live at the NIST-ASME Industrial Virtual Reality Symposium in Chicago (November 1-2, 1999).
During the Bushnet project in the late 90's, Clearwater Software developed Placemaker, a shared virtual world with raytraced 3D graphics, inspired by the MOO genre of shared online worlds.
Placemaker participants could play a number of games in the cyberworld including tic-tac-toe and checkers. Unlike most online graphical spaces before or since, Placemaker required only a standard web browser with no special plug-ins. Images were generated in real-time on the server, using a z-buffer image compositing scheme and a large library of pre-rendered ray-traced scene fragements.
Placemaker was retired in 1999. I still miss it.