2011

The new UCS is defined as shown in the following table
Define a UCS by selecting an object
Method of determining UCSObject
The center of the arc becomes the new UCS origin. The X axis
passes through the arc endpoint that is closest to the selection
point.
Arc
The center of the circle becomes the new UCS origin. The X axis
passes through the selection point.
Circle
The midpoint of the dimension text becomes the new UCS origin.
The direction of the new X axis is parallel to the X axis of the UCS
in effect when the dimension was drawn.
Dimension
The endpoint nearest the selection point becomes the new UCS
origin. The new X axis is set so that the line lies in the XZ plane of
Line
the new UCS. The line's second endpoint has a Y coordinate of
zero in the new UCS.
The point becomes the new UCS origin.Point
The start point of the polyline is the new UCS origin. The X axis
extends along the line segment from the start point to the next
vertex.
2D polyline
The first point of the solid determines the new UCS origin. The
new X axis lies along the line between the first two points.
Solid
The first point of the solid determines the new UCS origin. The
new X axis lies along the line between the first two points.
2D Solid
The “from” point of the trace becomes the UCS origin, with the
X axis lying along its centerline.
Trace
The new UCS origin is taken from the first point, the X axis from
the first two points, and the Y positive side from the first and fourth
points. The Z axis follows by application of the right-hand rule.
3D face
The insertion point of the object becomes the new UCS origin,
and the new X axis is defined by the rotation of the object about
Shape, text, block
reference, attrib-
ute definition
UCS | 1075