Three-dimensional space - Introduction to AutoCAD 2011: 2D and 3D Design - page 346

3D space

So far in this topic, when constructing 3D model drawings, they have been
constructed on the AutoCAD 2011 coordinate system which is based upon
three planes:

The XY Plane - the screen of the computer.
The XZ Plane at right angles to the XY Plane and as if coming towards
the operator of the computer.

A third plane ( YZ ) is lying at right angles to the other two planes ( Fig. 17.1 ).

Y

X Y P l a n e

0 , 0 , 0

X

Fig. 17.1 The 3D space planes

In earlier chapters the 3D Navigate drop-down menu and the ViewCube
have been described to enable 3D objects which have been constructed on
these three planes to be viewed from different viewing positions. Another
method of placing the model in 3D space using the Orbit tool has also
been described.

The User Coordinate System (UCS)

The XY plane is the basic UCS plane, which in terms of the ucs is known
as the *WORLD* plane.

The UCS allows the operator to place the AutoCAD coordinate system in

any position in 3D space using a variety of UCS tools (commands). Features
of the UCS can be called either by entering ucs at the command line or by
the selection of tools from the View/Coordinates panel ( Fig. 17.2 ). Note