The volume swept out by a moving 3-dimensional (3-D) solid has been recognized as important for the simulation of interference between moving solids. Its use has been proposed for the detection of collision (Ganter and Uicker, 1986), as well as for simulation of the machining process (Wang and Wang, 1986). This paper proposes: (a) a general approach for swept volume determination and (b) a method for interference detection that is based on 2-D projections of swept volumes.