You can relocate and rotate
the user coordinate system for convenient coordinate entry, grid
display, grid snap, Ortho mode, and other drawing tools.
Understand the World and
User Coordinate Systems
are two coordinate systems: a fixed system called the world coordinate
system (WCS) and a movable system called the user coordinate system
(UCS). By default, these two systems are coincident in a new drawing.
Normally in 2D views,
the WCS X axis is horizontal and the Y axis
is vertical. The WCS origin is where the X and Y axes
intersect (0,0). All objects in a drawing file are defined by their
WCS coordinates. However, it is usually more convenient to create
and edit objects based on the movable UCS.
Work with the User Coordinate System
all coordinate entry as well as many other tools and operations
reference the current UCS. 2D tools and operations that depend on
the location and orientation of the UCS include the following:
- Absolute and relative coordinate entry
- Absolute reference angles
- Definition of horizontal and vertical
for Ortho mode, polar tracking, object snap tracking, grid display,
and grid snap
- Orientation of horizontal and vertical
- Orientation of text objects
- View rotation using the PLAN command
Moving or rotating the UCS can make it easier
to work on particular areas of a drawing.
You can relocate the user coordinate system
with methods such as the following:
- Move the UCS by defining a new origin
- Align the UCS with an existing object.
- Rotate the UCS by specifying a new origin
point and a point on the new X axis.
- Rotate the current UCS a specified angle
around the Z axis.
- Revert to the previous UCS.
- Restore the UCS to be coincident with
of these methods have a corresponding option in the UCS command.
Once you have defined a UCS, you can name it and then restore it
when you need to use it again.
To define a new UCS origin
To change the rotation
angle of the UCS
To restore the UCS to be
coincident with the WCS
To restore the previous
To save a UCS
To restore a named UCS
To rename a UCS
To delete a named UCS