Finding feasible mold parting directions using graphics hardware

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.

[1]  Sara McMains,et al.  Finding feasible mold parting directions using graphics hardware , 2006, Comput. Aided Des..

[2]  Yong Chen,et al.  A Reverse Glue Approach to Automated Construction of Multi-Piece Molds , 2003, J. Comput. Inf. Sci. Eng..

[3]  Shuo-Yan Chou,et al.  Parting directions for mould and die design , 1993, Comput. Aided Des..

[4]  W. S. Sze,et al.  Parting line formation by slicing a 3D CAD model , 2005, Engineering with Computers.

[5]  Zhou-Ping Yin,et al.  Virtual prototyping of mold design: geometric mouldability analysis for near-net-shape manufactured parts by feature recognition and geometric reasoning , 2001, Comput. Aided Des..

[6]  Aristides A. G. Requicha,et al.  Accessibility analysis for planning of dimensional inspection with coordinate measuring machines , 1999, IEEE Trans. Robotics Autom..

[7]  Fritz B. Prinz,et al.  Rapid prototyping and manufacturing by gelcasting of metallic and ceramic slurries , 2002 .

[8]  Mark de Berg,et al.  Computational geometry: algorithms and applications , 1997 .

[9]  Rajit Gadh,et al.  Virtual Prototyping of Die Design Part One: Theory and Formulation , 1997 .

[10]  Mark de Berg,et al.  Computational Geometry: Algorithms and Applications, Second Edition , 2000 .

[11]  Yonghua Chen,et al.  Determining parting direction based on minimum bounding box and fuzzy logics , 1997 .

[12]  Jens H. Krüger,et al.  A Survey of General‐Purpose Computation on Graphics Hardware , 2007, Eurographics.

[13]  Shuo-Yan Chou,et al.  Partial visibility for selecting a parting direction in mold and die design , 1995 .

[14]  ARISTIDES A. G. REQUICHA,et al.  Representations for Rigid Solids: Theory, Methods, and Systems , 1980, CSUR.

[15]  Andrew Y. C. Nee,et al.  Generation of optimal parting direction based on undercut features in injection molded parts , 1999 .

[16]  鄺建華.  Computer-aided parting line and parting surface generation in mould design , 1992 .

[17]  Sanjay E. Sarma,et al.  Generating 5-axis NC roughing paths directly from a tessellated representation , 2000, Comput. Aided Des..

[18]  Andrew Y. C. Nee,et al.  Undercut feature recognition in an injection mould design system , 1999, Comput. Aided Des..

[19]  Masatomo Inui,et al.  Fast inverse offset computation using polygon rendering hardware , 2003, Comput. Aided Des..

[20]  Yong Chen,et al.  Computer-aided design for rapid tooling :methods for mold design and design-for-manufacture , 2001 .

[21]  Mark A. Ganter,et al.  Feature extraction for casting core development , 1993, DAC 1991.

[22]  Ralph R. Martin,et al.  Two-dimensional visibility charts for continuous curves , 2005, International Conference on Shape Modeling and Applications 2005 (SMI' 05).

[23]  Kim Seng Lee,et al.  A hybrid method for recognition of undercut features from moulded parts , 2001, Comput. Aided Des..

[24]  M. Inui,et al.  Fast visualization of NC milling result using graphics acceleration hardware , 2000, Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065).

[25]  David Rappaport,et al.  Moldable and Castable Polygons , 1994, Comput. Geom..

[26]  John F. Hughes,et al.  Hardware-determined feature edges , 2004, NPAR '04.

[27]  Sara McMains,et al.  Determining Moldability and Parting Directions for Polygons With Curved Edges , 2004 .

[28]  E. Groller,et al.  Real time simulation and visualization of NC milling processes for inhomogeneous materials on low-end graphics hardware , 1998, Proceedings. Computer Graphics International (Cat. No.98EX149).

[29]  Randima Fernando,et al.  GPU Gems: Programming Techniques, Tips and Tricks for Real-Time Graphics , 2004 .

[30]  Dinesh Manocha,et al.  Fast penetration depth computation for physically-based animation , 2002, SCA '02.

[31]  D. Ross.  Computer-aided design , 1961, CACM.

[32]  Jun Huang,et al.  A Feature-Based Approach to Automated Design of Multi-Piece Sacrificial Molds , 2001, J. Comput. Inf. Sci. Eng..

[33]  K. C. Hui,et al.  Mould design with sweep operations - a heuristic search approach , 1992, Comput. Aided Des..

[34]  Joseph O'Rourke,et al.  Computational geometry in C (2nd ed.) , 1998 .

[35]  Joseph O'Rourke,et al.  Computational Geometry in C. , 1995 .

[36]  Dan Halperin,et al.  Exact minkowski sums of convex polyhedra , 2005, SCG.

[37]  Jun Huang,et al.  Algorithms for Computing Global Accessibility Cones , 2003, J. Comput. Inf. Sci. Eng..

[38]  Tony C. Woo,et al.  Visibility maps and spherical algorithms , 1994, Comput. Aided Des..

[39]  Tom Davis,et al.  Opengl programming guide: the official guide to learning opengl , 1993 .

[40]  B. Ravi,et al.  Decision criteria for computer-aided parting surface design , 1990, Comput. Aided Des..

[41]  Dinesh Manocha,et al.  Collision queries using oriented bounding boxes , 2000 .

[42]  안희갑.  Separating an Object from its Cast. , 1997 .

[43]  Takafumi Saito,et al.  NC machining with G-buffer method , 1991, SIGGRAPH.

[44]  Lance Williams,et al.  Casting curved shadows on curved surfaces , 1978, SIGGRAPH.

[45]  Gershon Elber,et al.  Mold Accessibility via Gauss Map Analysis , 2005, J. Comput. Inf. Sci. Eng..

[46]  T. C. Woo,et al.  Spherical Maps: Their Construction, Properties, and Approximation , 1994 .

[47]  David Salesin,et al.  Rendering antialiased shadows with depth maps , 1987, SIGGRAPH.

[48]  Rajit Gadh,et al.  Virtual Prototyping of Die Design Part Two: Algorithmic, Computational, and Practical Considerations , 1997 .

[49]  Rahul Khardekar,et al.  Finding mold removal directions using graphics hardware , 2002 .

[50]  Michael T. Goodrich,et al.  Efficient perspective-accurate silhouette computation and applications , 2001, SCG '01.

[51]  Satyandra K. Gupta,et al.  Geometric algorithms for automated design of multi-piece permanent molds , 2004, Comput. Aided Des..