Abstract: This contribution describes some work being undertaken in the design and implementation of architectures for high performance Computer Image Generation for a range of applications from workstations to flight simulator visual systems. The work to be described uses a model based on a polygon representation anduses a Geometry Processor sub-system, with a flexible architecture known as MAGIC. This system performs the transformation of the polygon from the 3-D representation to the 2-D perspective projection to the viewing screen coordinates and also provides a clipping operation optional in 3-D or 2-D. Two different types of scan conversion system are described, the first the Zone Management Processor uses the coherence inherent in the polygon and the second system based on a Line Processor uses coherence with spans.