Sketch-based Retrieval and Instantiation of Parametric Parts

Abstract

Parametric parts can be instantiated into geometrically-different part instances, which presents a great challenge for the existing geometric-based sketch retrieval algorithms. Our main idea for this problem comes from the observation: if a sketch is used to retrieve its expected engineering part, it should be topologically similar with the part in certain view. Thus, we propose a view dependent topological graph representation, denoted as VD graph. A parametric part is approximated by VD graphs, which are usually smaller than a part’s attribute face graphs. Thus, a graph matching with VD graphs is more efficient. In addition, automatic algorithms are designed to construct VD graphs from a part’s mean shape, to construct sketch graphs, and to hierarchically search similar parametric parts. Finally, a prototype system with 50 parametric parts from the mechanical and furniture industries is implemented. We collected 200 sketches from 10 participants to test the algorithm’s accuracy and performance. The top-1 retrieval accuracy and time cost of our algorithm is 82% and 15 ms, compared to 12.53% and 1654 ms of state-of-the-art sketch retrieval approach, which was not specially designed for a parametric database. Our retrieval technique is a useful interactive tool for sketch-based product assembly modeling.