3DCanvas is the carrier of the EZ graphics library. All graphical primitives are realized through 3DCanvases. To each 3DCanvas, there is an associated data structure called the graphics context which contains the entire state attributes of the graphics library. An application can have as many 3DCanvases as it needs. However, there is only one active 3DCanvas at any given instant. Implicitly, the active 3DCanvas is set to the last created 3DCanvas.