2011

Table Of Contents
The following illustration shows the same model in both a parallel projection
and perspective projection. Both are based on the same viewing direction.
Quick Reference
Commands
3DORBIT
Rotates the view in 3D space, but constrained to horizontal and vertical orbit
only.
DVIEW
Defines parallel projection or perspective views by using a camera and target.
System Variables
BACKZ
Stores the back clipping plane offset from the target plane for the current
viewport, in drawing units.
FRONTZ
Stores the front clipping plane offset from the target plane for the current
viewport, in drawing units.
LENSLENGTH
Stores the length of the lens (in millimeters) used in perspective viewing.
TARGET
Stores the location (as a UCS coordinate) of the target point for the current
viewport.
VIEWDIR
Stores the viewing direction in the current viewport, expressed in UCS
coordinates.
86 | Chapter 10 Change Views