Choosing A Solid Modeler for CAD/CAM Integration

ME 459 Advanced Topics in Design and Manufacturing

1. Requirements

• Flexibility - A solid modeler should address solids of all shapes.
• Robustness - the modeler should produce a consistent and proper solid.
• Simplicity - User friendly and ease to use.
• Performance - Speed and efficiency.
• Economy - use workstations and microcomputers.

2. Feature Recognition

	Model representation	Feature representation
CSG	Implicit	Explicit
B-Rep	Explicit	Implicit

• CSG stores a model in a "unevaluated" implicit form. i.e. the faces, edges, and bertices of the part must be calculated from the set operation on the primitives. An objects features, such as holes, slots, etc may actually be present in the CSG tree.
• B-Rep contains an explicit or "evaluated" model of the faces, edges, and vertices. The features are implicit, requiring interpretation of the geometry and topology.