When a document becomes a lot of 3D bodies visually determine the intersection between the bodies, especially if this intersection is small is very difficult. In AutoCAD for this there is a special command «Test interactions» it can be called from the «Edit» menu, the submenu «3D operations». You can also run this command directly from the command line by typing _interfere and pressing Enter.
After running the command, you will need to alternately select two sets of bodies.
The result of the team will be the creation of temporary objects-bodies or surfaces with the allocation of the intersection area of the models.
If the set of objects contains both 3D bodies and surfaces, then the resulting interaction object will be the surface.
For network objects, interaction checking is not performed. But if network objects are selected, they can be transformed into a body object or surface and the operation can continue.