Tài liệu Drawing Complex Objects

Follow these steps:
1. The Object Type drop-down list determines the type of object BOUNDARY creates.
Choose either Region or Polyline.
2. Choose the boundary set, which is the area AutoCAD analyzes to create the
boundary. Usually, you can accept the default of Current Viewport. However,
if you have a very complex drawing, choose New to temporarily return to
your drawing. Specify a window around the area you want for the boundary
set. AutoCAD returns you to the dialog box.
3. To specify the enclosed area for the boundary, choose Pick Points. AutoCAD
returns you to your drawing with the Select internal point: prompt.
4. Pick any point inside the closed area you want for your boundary. AutoCAD
starts to think as follows:
Selecting everything .Selecting everything visible .
Analyzing the selected data .Analyzing internal islands .
5. AutoCAD then prompts you for another internal point. If you want to create
other boundaries, continue to pick internal points. Press Enter to end point
selection