VAM: Video Aided Modeling for Shape Reconstruction and Re-Design

Although the 3D shape recovery of a real object have been greatly improved in the last few years, modeling a complex virtual object by starting from the real prototype is still a very time-consuming activity. In this paper an originally conceived method and testing software to recover a CAD model from a real object is pre sented. The developed software tool joins a professional Computer-Aided Design (CAD) and a Mixed Reality (MR) tool in the same interface, enabling the operator to use standard CAD tools and features together with a camera, which provides external image streaming displayed in the workspace background. Moreover, a special programmed library performs a real-time calculation of camera position and other parameters with respect to standard markers in order to drive the CAD 3D virtual camera and align it to external world. In that way rendered virtual models may be superimposed to external images of reality grabbed by the video camera. Thus with MR-CAD tool the operator may easily recover a complex shape directly from the external views of a real object or may start the object re-design from the previous re constructed geometry. Furthermore the interface is totally integrated in a CAD environment, both avoiding to work with unfamiliar new software and exploiting CAD geometry database and tools. Finally, MR-CAD can be considered a signicant step ahead in the bi-directional interaction of virtual and real models, reducing also the gap between real prototypes and CAD data.