Combines selected 3D solids, surfaces, or 2D regions by addition.
Button
Ribbon: Home tab
Solid
Editing panelUnionNot available on the ribbon
in the current workspace Menu: Modify Solid
Editing UnionNot available in menus
in the current workspace Toolbar: Modeling
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:
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.
You cannot use UNION with mesh objects. However, if you select a mesh object, you will be prompted to convert it to a 3D solid or surface.
