Design review of CAD assemblies using bimanual natural interface.

The interaction metaphor, based on mouse, monitor and keyboard, presents evident limits in the engineering design review activities, when real and virtual models must be explored and compared, and also in "outside-the-office" environments, where the desk is not available. The presented research aims to explore a new generation of gesture-based interfaces, called "natural interfaces", which promise an intuitive control using free hands and without the desk support. We present a novel natural design review workspace which acquires user motion using a combination of video and depth cameras and visualizes the CAD models using monitor-based augmented reality. We implemented a bimanual egocentric pointer paradigm by a virtual active surface in front of the user. We used a XML configurable approach to explore bimanual gesture commands to browse, select, dis/assembly and explode 3D complex models imported in standard STEP format. Our experiments demonstrated that the virtual active surface is able to effectively trigger a set of CAD specific commands and to improve technical navigation in non-desktop environments: e.g. shop floor maintenance, on site quality control, etc. We evaluated the feasibility and robustness of the interface and reported a high degree of acceptance from the users who preferred the presented interface to a unconstrained 3D manipulation.