Visualization in GEANT4 Presented at HEPVIS96

The Visualization System of GEANT4 is an interface between the simulation kernel and the graphics system. In itself it defines only the functionality required by the kernel and the GEANT4 user. It contains an abstract interface to which an installer may fit his or her favourite graphics system; concrete interfaces to some graphics systems come ready-to-use with the GEANT4 toolkit. Commands to the graphics system(s) are channelled through or initiated by the Visualization Manager. There exist basic facilities for debugging, development and publicity which hopefully can evolve as effort accumulates and graphics systems become more powerful. This document describes those facilities and is intended to act as a GEANT4 Visualization Primer.