The graphics subsytem is the part of a VR system's reality engine which handles image generation. This article will describe the purpose, general architecture, capabilities, and functionality of a typical graphics subsystem and discuss example subsystems. The computer science foundation areas of computer architecture, operating systems, and algorithms along with the specialized area of computer graphics provide the background knowledge to design the subsystem's processing hardware and interfaces. However, because effort is expended in the communications, the bus between the CPU and the GS must have the bandwidth to make the advantage worthwhile. Thus, when selecting or designing a GS it is important to be aware of the capabilities of the bus interface.
Alpha values specify the degree of transparency from sheer to opaque.
For accuracy of hidden surface removal especially for distant objects, the Z-buffer should be at least 24 bits deep. A key texture mapping feature is mipmapping which involves the generation of prefiltered lower resolution versions of a texture which closely fit the varying sized polygons to which they are applied. Other important considerations include available object cache and the application programming interface. Transformations can be performed on the objects to position them accordingly in the scene. This can improve performance by cutting down traffic on the CPU to GS bus.