: If you have a planar opening (a flat hole) in a polysurface, the Cap command will create a flat surface to seal it and turn it into a solid.
: Select a group of intersecting surfaces or polysurfaces that "box in" a volume. Rhino will trim the excess and join the pieces into a single closed solid. Rhinoceros 7.24.22297.11002 RC
: Run this and select Naked Edges . If any edges highlight in magenta, your object is not yet a solid and has gaps that need to be closed. : If you have a planar opening (a
: Select your object; the type should read "closed solid polysurface." Specific Version Note : Run this and select Naked Edges
To ensure your feature is truly "solid" (water-tight for 3D printing or boolean operations):
: Use this to combine adjacent surfaces. Once all edges are joined and there are no holes, the object automatically becomes a "Closed Solid Polysurface".