Boolean operations are actions that trim surfaces to create the appearance of a union, intersection, or subtraction between two objects.
To perform a boolean operation on a surface
The order in which you click the surfaces only matters for the Difference tool. Maya subtracts the second surface you click from the first.
Sphere selected first
Torus selected first
Maya groups the combined surfaces.
You can make the following adjustments after creating the Boolean shape:
The only way to retrieve the original objects after a Boolean operation is to use Undo.
If you get a “not a valid NURBS shell” error it means the boolean tool cannot create meaningful geometry from the surfaces you clicked.
For example, in the following illustration, the horizontal cylinder does not enclose a space that can be combined with the vertical cylinder. If you move the horizontal cylinder up, the boolean actions will work.