Automatic Learning of User Design Rationale from Examples Bhaskar Bandyopadhyay1, Abhishek Jain1, Yao-Yi Chiang2, Craig Knoblock3 Computer Science Department1, Spatial Sciences Institute2, Information Sciences Institute3 , University of Southern California Background Problems and Hypothesis Computer Aided Design (CAD) interchange formats: Inadequate coverage of design knowledge We are building a framework that ▪ STEP: gives the user the flexibility to • STandard for the Exchange of Product model data Heterogeneous CAD systems and data define and use a rich semantic • (ISO 10303-21 or .step/ .stp / .p21) formats (Catia, Solidworks, AutoCAD, etc) model beyond the current ▪ IGES: standards. • Initial Graphics Exchange Specification The lack of capabilities to capture errors in Our approach will be able to CAD kernels: ParaSolid, ACIS, ShapeManager, CGM translating CAD data between data formats efficiently map a CAD file from / to a Proprietary ways of interpreting these formats leads to user-defined ontological ambiguity while editing. Slow evolution of CAD neutral format representation,thus achieving How can we mitigate this interoperability problem ? standards (AP214/STEP made in 1994-2014) interoperability. TheThe STEP STEP formatformat RelationsRelations to Modelto modelIntent intent ExamplesExamples • Stack of Cubes Only saves geometrical data and • Relations can help resolving ambiguity some topological structure • Constrained editing of CAD easier • Missing relations • However – If we have very few or no relations : Ambiguity (the • Missing original sketches cube example video) • Ball Bearing • Missing operations – Too many relations : Lack of flexibility (the ball (Extrude, Cut…) bearing example video) – Manually adding relations is tedious What about Design Intent ? • Eg. Coradial, Parallel, Fixed, Dimension Architecture and Algorithm Extract all relations and sketch Extract All Relations model Extract all relations and sketch again. And save a copy of part User marks and Sketches (Valid) change/save Invalid from invalidated part. ADDIN file. CONSTRAINT Entity FIXER Extraction Valid Sketches Aligns Apply the transformation, create the diff of change Apply with Apply relations to the Invalid Sketches Relation which caused part to be in relations (Valid - CAD S/W Inferred User last valid model Inference invalidated. Invalid) Relation Engine Intent No Show Inferred Relations Models with them Rank them based on the %age Infer Relations Generate Combinations of of relations that can be applied (Fixed,Dimension) the inferred relations and number of relations Results, Current and Future Work • The interoperability of STEP can • Testing the performance of • Developing newer algorithms where be enhanced by our filtering out results from current approaches might fail automatically inferred relations constraint sets • Learning heuristics for automation • Design intent can be derived for • What kind of design issues • Incorporating semantic info and simple models can be resolved? translating them to CAD commands • Project Github Repository [ https://github.com/spatial-computing/Karma-CAD ] • Project Github Wiki [ https://github.com/spatial-computing/Karma-CAD/wiki ].