I want to make a boolean difference with two speheres. The smaller one is entirely in the bigger one.
So the smaller one is centered inside the bigger one.
The Rhino doesn’t make it.
It says:
Command: _BooleanDifference
Select surfaces or polysurfaces to subtract with ( DeleteInput=Yes )
Select surfaces or polysurfaces to subtract with. Press Enter when done ( DeleteInput=Yes )
Boolean difference in progress… Press Esc to cancel
Objects do not intersect. Nothing done.
Same with two boxes.
Please, why does it do this?
The making of hollow spheres is prohibited?
Thank you!
There needs to be an intersection for the boolean commands to work. Imagine two volumes that are next to each other that do not touch or overlap; same situation! Nested volumes do not touch. Its weird, I know, but that’s the ‘math magic’ reasoning behind your situation.
Visual a bottle: there is an opening at the top – and both inside and outside walls connect. That makes sense. (They are continuous and, by the way, this would be best made as a revolve.)
So, for your example, make a small cylindrical hole on the bottom (or somewhere not noticable) that connects the inner and outer non-touching surfaces. Once there is a ‘connection’ you will be in BIZNESS.
Having wall thickness is also critical for accurate renderings. Using a car window example, students usually make one of two common mistakes:
The window is a single surface with no thickness
The ‘window’ is a giant volume inside the vehicle. It appears as if the occupants are ‘cast’ inside a giant blob of glass.
All windows or vessels will have a uniform wall thickness consisting of two sides.
