5.5.2 Merge

There is a variant of union namely merge, with syntax:

MERGE:
  merge { SOLID_OBJECT SOLID_OBJECT... [OBJECT_MODIFIERS] }

See also:

• [pov:6.5.6.5]Merge
• [pov:3.3.5]CSG Merge
• www.f-lohmueller.de/.../povcsg2e.htm

The difference between merge and union is that in a merge the internal parts of surfaces are removed.

Figure: Merged spheres