All sorts of real time graphics stuff; flight simulators, oil and gas visualization of voxel maps, general industrial visualization. These were the early days of hardware accelerated 3D and everyone thought that visualization would change the world to a greater extent than it really did.

It was great fun to write code which drove 8 displays using 8 graphics pipes, with roughly 8 cores working in concert with each pipe. All this work for something that runs faster on the latest iphone using a single thread...

I went on to work at SGI for a few years, and it was still my favorite job ever. It was pure R&D, graphics and realtime systems for their own sake. Today, this doesn't exist. 3D graphics are an applied technology that's part of an app, but not a product research area of its own.