I posted a query about this in my introduction which was probably not appropriate .
Can an object being prepared for 3d printing be constructed from a number of smaller 'sub-objects'? For example if I wanted to model a rivet on a surface could the rivet be a separate 'watertight' sphere and intersect the surface ( of equally watertight geometry)?
If so then is there a good guideline for the amount one object should intersect another?
By intersecting I mean that two 'watertight' objects in a scene are overlapping.
To use a 3DSMax example - two objects in a scene are 'attached' but ,on a 'sub-object' level, they are still two distinct closed objects. My sphere rivet would have parts of its surface inside the volume of the larger plane to which it has been attached.