Wikipedia
RealityEngine is a 3D graphics hardware architecture and a family of graphics systems which was developed and manufactured by Silicon Graphics during the early to mid 1990s. RealityEngine was positioned as the company's high-end visualization hardware for its MIPS/ IRIX platform. RealityEngine is designed for deployment exclusively within the company's Crimson and Onyx family of visualization systems, which are sometimes referred to as "graphics supercomputers" or "visualization supercomputers". The RealityEngine was marketed to large organizations, such as companies and universities that are involved in computer simulation, digital content creation, engineering and research.
It was succeeded by the InfiniteReality in early 1996, but coexisted with it for a time as an entry-level option for older systems.