2011

Summary
You can combine two or more 3D solids, surfaces, or 2D regions into a single,
composite 3D solid, surface, or region. You must select the same type of objects
to combine.
Using the Union Command with Surfaces
Although you can use the UNION command with surfaces, it will cause the
surface to lose associativity. Instead, it is recommended that you use the surface
editing commands:
■
SURFBLEND on page 1013
■ SURFFILLET on page 1015
■ SURFPATCH on page 1021
Using the Union Command with Solids and Regions
The selection set can contain objects that lie in any number of arbitrary planes.
For mixed object types, selection sets are divided into subsets that are joined
separately. Solids are grouped in the first subset. The first selected region and
all subsequent coplanar regions are grouped in the second set, and so on.
The resulting composite solid includes the volume enclosed by all of the
selected solids. Each of the resulting composite regions encloses the area of
all regions in a subset.
1094 | Chapter 21 U Commands