Exploring the Trim Options

Exploring the Trim Options
AutoCAD offers six options for the Trim command: Fence, Crossing, Project, Edge, eRase, and
Undo. As described in the following paragraphs, these options give you a higher degree of control
over how objects are trimmed:
Edge [E] Lets you trim an object to an apparent intersection, even if the cutting-edge object
doesn’t intersect the object to be trimmed. (See the top of Figure 3.6.) Edge offers two options:
Extend and No Extend. You can also set these options by using the Edgemode system variable.



Project [P] Useful when you’re working on 3D drawings. It controls how AutoCAD trims
objects that aren’t coplanar. Project offers three options: None, UCS, and View. The None option
causes Trim to ignore objects that are on different planes so that only coplanar objects are trimmed.
If you choose UCS, the Trim command trims objects based on a plan view of the current UCS and
then disregards whether the objects are coplanar. (See the middle of Figure 3.6.) View is similar
to UCS but uses the current view’s “line of sight” to determine how non-coplanar objects are
trimmed. (See the bottom of Figure 3.6.)
eRase [R] Allows you to erase an object while remaining in the Trim command.
Fence/Crossing [F or C] Lets you use a Fence or Crossing window to select objects.
Undo [U] Causes the last trimmed object to revert to its original length.
You’ve just seen one way to construct the toilet. However, you can construct objects in many
ways. For example, you can trim only the top of the ellipse, as you did in the first Trim exercise, and
then use the Grips feature to move the endpoints of the line to meet the endpoints of the ellipse. As
you become familiar with AutoCAD, you’ll start to develop your own ways of working, using the
tools best suited to your style.
If you’d like to take a break, now is a good time. You can exit AutoCAD and then come back to
the Bath drawing file when you’re ready to proceed.