Take a look at the new version of this page: [ beta version ]. Tell us what you think.

ABSTRACT

We present new programmable graphics hardware accelerated algorithms to test the castability of geometric parts and assist with part redesign. These algorithms efficiently identify and graphically display undercuts and minimum and insufficient draft angles. Their running times grow only linearly with respect to the number of facets in the solid model, making them efficient subroutines for our algorithms that test whether a tessellated CAD model can be manufactured in a two-part mold. We have developed and implemented two such algorithms to choose candidate directions to test for castability using accessibility analysis and Gauss maps. The efficiency of these algorithms lies in that they identify groups of candidate directions such that if any one direction in the group is not castable, none are, or if any one is castable, all are. We examine trade-offs between the algorithms' speed, accuracy, and whether they guarantee that a castable direction will be found for a part if one exists.

REFERENCES

• 1: Ahn, H.-K., de Berg, M., Bose, P., Cheng, S.-W., Halperin, D., Matousek, J., and Schwarzkopf, O. 2002. Separating an object from its cast. Computer-Aided Design 34, 547--59.
• 2: Balasubramaniam, M., Laxmiprasad, P., Sarma, S., and Shaikh, Z. 2000. Generating 5-axis NC roughing paths directly from a tessellated representation. Computer-Aided Design 32, 4 (April), 261--77.
• 3: Cgal.Org, 2004. Computational Geometry Algorithms Library. http://www.cgal.org.
• 4: Chen, L.-L., and Chou, S.-Y. 1995. Partial Visibility for Selecting a Parting Direction in Mold and Die Design. Journal of Manufacturing Systems 14, 5, 319--330.
• 5: Chen, Y., and Rosen, D. W. 2003. A reverse glue approach to automated construction of multi-piece molds. Journal of Computing and Information Science in Engineering 3, 3, 219--230.
• 6: Chen, L.-L., chou, S.-Y., and Woo, T. C. 1993, Parting directions for mould and die design. Computer-Aided Design 25, 12 (December), 762--768.
• 7: Chen, Y. H. 1997. Determining parting direction based on minimum bounding box and fuzzy logics. Int. J. Mach. Tools Manufact. 37, 9, 1189--1199.
• 8: Chen, Y. 2001. Computer-Aided Design for Rapid Tooling: Methods for Mold Design and Design-for-Manufacture. PhD thesis, Georgia Institute of Technology.
• 9: Mark de Berg , Marc van Kreveld , Mark Overmars , Otfried Schwarzkopf, Computational geometry: algorithms and applications, Springer-Verlag New York, Inc., Secaucus, NJ, 1997
• 10: Dhaliwal, S., Gupta, S., Huang, J., and Kumar, M. 2001. A feature based approach to automated design of multi-piece sacrificial molds. ASME Journal of Computing and Information Science in Engineering 1, 3, 225--234.
• 11: Dhaliwal, S., Gupta, S., Huang, J., and Priyadarshi, A. 2003. Algorithms for computing global accessiblity cones. Journal of Computing and Information Science in Engineering 3, 3 (September), 200--209.
• 12: Mold Accessibility via Gauss Map Analysis, Proceedings of the Shape Modeling International 2004 (SMI'04), p.263-272, June 07-09, 2004 [doi>10.1109/SMI.2004.41]
• 13: Everitt, C., Rege, A., and Cebenoyan, C., 2003. Interactive geometric and scientific computation using graphics hardware. ACM SIGGRAPH 2003 Course #11 Notes, July.
• 14: Randima Fernando, GPU Gems: Programming Techniques, Tips and Tricks for Real-Time Graphics, Pearson Higher Education, 2004
• 15: Fu, M. W., Fuh, J. Y. H., and Nee, A. Y. C. 1999. Generation of optimal parting direction based on undercut features in injection molded parts. IIE Transactions 31, 947--955.
• 16: Fu, M. W., Fuh, J. Y. H., and Nee, A. Y. C. 1999. Undercut feature recognition in an injection mould design system. Computer-Aided Design 31, 12 (October), 777--790.
• 17: Gan, J. G., Woo, T. C., and Tang, K. 1994. Spherical maps: their construction, properties and approximation. Journal of Mechanical Design 116, 2 (June), 357--363.
• 18: Ganter, M. A., and Skoglund, P. A. 1991. Feature extraction for casting core development. In 17th Design Automation, Conference presented at the 1991 ASME Design Technical Conferences, American Society of Mechanical Engineers, 93--100.
• 19: Stefan Aric Gottschalk , Dinesh Manocha , Ming C. Lin, Collision queries using oriented bounding boxes, 2000
• 20: Hui, K. C., and Tan, S. T. 1992. Mould design with sweep operations - a heuristic search approach. Computer-Aided Design 24, 2 (February), 81--91.
• 21: Inui, M., and Kakio, R. 2000. Fast visualization of NC milling result using graphics acceleration hardware. In IEEE International Conference on Robotics and Automation, IEEE, 3089--94.
• 22: Inui, M. 2003. Fast inverse offset computation using polygon rendering hardware. Computer Aided Design 35, 2 (February), 191--201.
• 23: Khardekar, R., and Mcmains, S. 2004. Finding mold removal directions using graphics hardware. In ACM Workshop on General Purpose Computing on Graphics Processors, C-19. (abstract).
• 24: A. H. König , E. Gröller, Real Time Simulation and Visualization of NC Milling Processes for Inhomogeneous Materials on Low-End Graphics Hardware, Proceedings of the Computer Graphics International 1998, p.338, June 22-26, 1998
• 25: Kwong, K. 1992. Computer-aided parting line and parting surface generation in mould design. PhD thesis, The university of Hong Kong, Hong Kong.
• 26: Lin, M. C., and Manocha, D. 2003. SIGGRAPH 2003 Course Notes, vol. 11. ACM SIGGRAPH, July, ch. Interactive Geometric and Scientific Computations Using Graphics Hardware, 1--6.
• 27: Morgan McGuire , John F. Hughes, Hardware-determined feature edges, Proceedings of the 3rd international symposium on Non-photorealistic animation and rendering, June 07-09, 2004, Annecy, France [doi>10.1145/987657.987663]
• 28: McMains, S., and Chen, X. 2004. Determining Moldability and Parting Directions for Polygons with Curved Edges. In International Mechanical Engineering Congress and Exposition, ASME, IMECE2004--62227.
• 29: Joseph O'Rourke, Computational geometry in C (2nd ed.), Cambridge University Press, New York, NY, 1998
• 30: Mihai Pop , Christian Duncan , Gill Barequet , Michael Goodrich , Wenjing Huang , Subodh Kumar, Efficient perspective-accurate silhouette computation and applications, Proceedings of the seventeenth annual symposium on Computational geometry, p.60-68, June 2001, Medford, Massachusetts, United States [doi>10.1145/378583.378618]
• 31: David Rappaport , Arnold Rosenbloom, Moldable and castable polygons, Computational Geometry: Theory and Applications, v.4 n.4, p.219-233, Aug. 1994 [doi>10.1016/0925-7721(94)90020-5]
• 32: R. Ravi , M. N. Srinivasan, Decision criteria for computer-aided parting surface design, Computer-Aided Design, v.22 n.1, p.11-17, January/February 1990 [doi>10.1016/0010-4485(90)90024-7]
• 33: Aristides G. Requicha, Representations for Rigid Solids: Theory, Methods, and Systems, ACM Computing Surveys (CSUR), v.12 n.4, p.437-464, Dec. 1980 [doi>10.1145/356827.356833]
• 34: Takafumi Saito , Tokiichiro Takahashi, NC machining with G-buffer method, ACM SIGGRAPH Computer Graphics, v.25 n.4, p.207-216, July 1991 [doi>10.1145/127719.122741]
• 35: Spitz, S., Spyridi, A., and Requicha, A. 1999. Accessibility analysis for planning of dimensional inspection with coordinate measuring machines. IEEE Transactions on Robotics and Automation, 714--27.
• 36: Stampfl, J., Liu, H.-C., Nam, S. W., Sakamoto, K., Tsuru, H., Kang, S., Cooper, A. G., Nickel, A., and Prinz, F. B. 2002. Rapid prototyping and manufacturing by gelcasting of metallic and ceramic slurries. Materials Science & Engineering. 334, 1--2 (Sep), 187--192.
• 37: Wong, T., Tan, S. T., and Sze, W. S. 1998. Parting line formation by slicing a 3D CAD model. Engineering with Computers 14, 4, 330--343.
• 38: Woo, T. C. 1994. Visibility maps and spherical algorithms. Computer-Aided Design 26, 1 (January).
• 39: Wuerger, D., and Gadh, R. 1997. Virtual Prototyping of Die Design Part One: Theory and Formulation. Concurrent Engineering: Research and Applications 5, 4 (December), 307--315.
• 40: Wuerger, D., and Gadh, R. 1997. Virtual Prototyping of Die Design Part Two: Algorithmic, Computational, and Practical Considerations. Concurrent Engineering: Research and Applications 5, 4 (December), 317--326.
• 41: Ye, X. G., Fuh, J. Y. H., and Lee, K. S. 2001. A hybrid method for recognition of undercut features from moulded parts. Computer-Aided Design 33, 1023--1034.
• 42: Yin, Z., Ding, H., and Xiong, Y. 2001. Virtual prototyping of mold design: geometric mouldability analysis for near-netshape manufactured parts by feature recognition and geometric reasoning. Computer-Aided Design 33, 137--154.