2011

OSOPTIONS
Automatically suppresses object snaps on hatch objects and geometry with
negative Z values when using a dynamic UCS.
UCSDETECT
Controls whether dynamic UCS acquisition is active or not.
Assign User Coordinate System Orientations to Viewports
To facilitate editing objects in different views, you can define a different user
coordinate system orientation for each view.
Multiple viewports provide different views of your model. For example, you
might set up viewports that display top, front, right side, and isometric views.
To facilitate editing objects in different views, you can define a different UCS
for each view. Each time you make a viewport current, you can begin drawing
using the same UCS you used the last time that viewport was current.
The UCS in each viewport is controlled by the UCSVP system variable. When
UCSVP is set to 1 in a viewport, the UCS last used in that viewport is saved
with the viewport and is restored when the viewport is made current again.
When UCSVP is set to 0 in a viewport, its UCS is always the same as the UCS
in the current viewport.
For example, you might set up three viewports: a top view, front view, and
isometric view. If you set the UCSVP system variable to 0 in the isometric
viewport, you can use the Top UCS in both the top viewport and the isometric
viewport. When you make the top viewport current, the isometric viewport's
UCS reflects the UCS top viewport. Likewise, making the front viewport current
switches the isometric viewport's UCS to match that of the front viewport.
The example is illustrated in the following figures. The first figure shows the
isometric viewport reflecting the UCS of the upper-left, or top, viewport, which
is current.
574 | Chapter 17 Use Precision Tools