Select one or more SDS objects and one tool object (selected last). Set the tool options on the Control Bar and accept the tool.
The object knife tool has the following options:
Selected - If checked only selected edges can be cut, otherwise all edges can be cut.
Add Edges - If checked connects the new vertices with new edges to divide the faces into smaller faces, otherwise creates only the vertices where the knife object cuts the edges.
Select - Select which faces will be selected after cutting.
No selection - No faces will be selected
Inside - The faces inside the tool object will be selected
Outside - The faces outside the tool object will be selected
The selection is based on the center point of the face (whether it is inside or outside the tool object).