On the role of geometric constraints to support design intent communication and model reusability

Abstract

The assurance of model quality in parametric CAD implies that designers must build models that facilitate reuse while retaining their design intent when modified. In this context, a suitable selection of geometric constraints that operate within and between features is key to produce robust-while-flexible models which are a prerequisite for reusability. This paper introduces a new classification of 3D CAD model constraints that builds on the idea that making the meanings, similarities and differences explicit can result in better usage, making models robust to prevent catastrophic failures when edited as well as flexible enough to enable easy editing. Results from a preliminary user study designed to validate the significance of the new classification are discussed. Simple exposure to the proposed classification appears insufficient to validate effectiveness. Future work on educational approaches that focus on the challenges of selecting an effective set of constraints for particular reuse scenarios is suggested.