Combines multiple individual parts into one part containing all shells from the original parts
- Select two or more parts.
- Click
Modify >
Edit shells > 
Merge selected parts.
- Click Yes to replace the current parts with the merged part or click No to create a new part.
Left: Three overlapping parts. Right: The same parts, merged into one.
Note: Merging parts does
not resolve self-intersections. This is intentional. If you do need to merge parts and have self-intersections resolved, use
Boolean Unify instead, or follow-up with
repair, namely using Wrap surfaces or
Split self-intersections, followed by selective deletion of unneeded shells and applying
Stitch triangles. The difference between these two methods is that Boolean ops require all involved parts to be
closed and oriented while Merge can handle broken meshes.