A computer-implemented product including instructions embodied in a non-transitory computer read-able medium that, when executed by a processor, cause the processor to receive input selecting one of a plurality of faces of a boundary representation model of an object. The computer-implemented product may include further instructions to identify boundary edges of the model outside the one of the faces not separated from the one of the faces by an intervening concave or convex edge. The boundary edges may define a perimeter of a topological feature containing the one of the faces. The computer-implemented product may include further instructions to identify a set of the faces including the one of the faces contained by the perimeter and generate output highlighting the boundary edges and set of the faces of the topological feature.