Live parametric design modifications in CAD-linked virtual environment

This paper presents a solution to support parametric design modification in a virtual reality (VR) environment. It builds upon a novel computer-aided design (CAD) and VR integration framework, namely, CAD-linked virtual reality environment. With this framework, semantic information in CAD models, such as constraints, design features, and parametric settings can be automatically extracted during the creation of VR environment and be integrated into the virtual assembly (VA) models. Moreover, the persistent naming mechanism originating from feature-based modeling technology is introduced into the CAD–VR integration, based on which a persistent linkage between VA models and their CAD counterparts can be established. Users are able to visualize design features and to access the associated parametric info in VR environment and also to change the parametric settings online whenever necessary. The modified parametric settings are then sent back to the linked CAD models so that parts can be re-evaluated. The modified CAD part can then be reloaded into the VA model under an automated mechanism. Such communications between CAD and VR applications are supported in a live mode utilizing the COM interfaces provided by CAD server. With this solution, a quick return loop from VR to CAD is achieved. Therefore, it provides the possibility to support quick design change review and “what-if” evaluations for applications such as collaborative system design and immersive project review in VR. This constitutes the major contribution of the work to product development process.