Research Status on MultiResolution Modeling System Youngjae Song

Research Status on Multi-Resolution Modeling System Youngjae Song CAD Lab, . Seoul National Univ.

Contents l Previous Work – Simplification of B-rep based CAD Model – Simplification of Feature based CAD Model – Proposed System Architecture for Multi-resolution model. l Current Status – Streaming B-rep Model using Wrap-around operation – Feature based Modeling syst. supporting multi-resolution l Examples l Discussion National Research Laboratory (CAD Lab. @ SNU)

Simplification of B-rep Model l Wrap-around – Remove the small local features from the model. – 1. Removal of the concave regions. – 2. Removal of the holes. (convex inner loops in the faces) – 3. Removal of fillet/round, and chamfer. National Research Laboratory (CAD Lab. @ SNU)

Simplification of Feature Model l Feature re-ordering scheme – Sort the feature list in the order of decreasing contribution volume to the entire model. – Developing the our own Feature-based Modeler. ; limitations of the Solid. Works APIs – ID system for the consistent entity naming. ; face, edge, vertex… National Research Laboratory (CAD Lab. @ SNU)

Proposed System Architecture l General Procedure Solidworks Feature Information MRModeler Feature Regeneration (Define LOD level) Feature Reordering (delta volume, small volume feature removal, sketch simplification) Constraint Simplification Feature suppression LOD tree & Display National Research Laboratory (CAD Lab. @ SNU)

Streaming B-rep Model (1) l Application of the Wrap-around operator to the network transmission of B-rep model. l Model Server; – Sequentially apply the WA operation to original model. – Generate the list of face groups sorted in the order of decreasing contribution to the original. l Model Client; – Sequentially apply the Reverse WA operation to first-sent solid model. – Reconstruct the original shape with the received faces. National Research Laboratory (CAD Lab. @ SNU)

Streaming B-rep Model (2) l Examples Client Program Server Program National Research Laboratory (CAD Lab. @ SNU)

Streaming B-rep Model (3) l More Complex Examples – Including the newly added Wrap-around function. Ex) Fillet/Round, Chamfer… l Developing the efficient algorithm for the assemblylevel Wrap-around operation. – Finding the outer-most faces. National Research Laboratory (CAD Lab. @ SNU)

Feature-based Modeling system l Interface to Solid. Works. – Extract all the possible feature information from Solid. Works. – Reconstruct the feature model in our one system. • Own ID system. • Some modeling functions to add the loss feature information. – Available feature set consistent with Solid. Works. • Extrude-Boss, Extrude-Cut, Sweep, Fillet, Chamfer, Patten, etc. National Research Laboratory (CAD Lab. @ SNU)

Feature-based Modeling system l Examples National Research Laboratory (CAD Lab. @ SNU)

Schedule l Overall Schedule Research Topic 1 2 3 4 5 6 7 8 9 10 Wrap-around operation B-rep Streaming Feature-based Modeler Feature Reordering System National Research Laboratory (CAD Lab. @ SNU)

Discussion l Some Other Issues – Integration of Wrap-around operation into Feature-based modeling system. • Assign the access level to each LOD of models. – Introducing the skeleton model to the solid model. • Integration of Human model and solid model. • Integration of modeling system and simulation system. – Performance of Feature Reordering System. • Real-Time generation of the selected LOD models. • Enhancements for very large assembly model. National Research Laboratory (CAD Lab. @ SNU)