View-dependent Virtual and Augmented Reality for Machine Tools

In recent papers, the concept of an intelligent window for machine tools (iWindow) using virtual and augmented reality in order to replace traditional windows in machine tools was introduced. Such intelligent windows provide additional possibilities for observing the machine interior under difficult visibility conditions, combine and reduce the number of supporting systems and enrich the machine interior with contextual information. For creating a view-dependent virtual and augmented reality individual solution approaches presented in other research were combined, extended and applied to machine tools to form an intelligent window. For the impression of a real window and perspectively correctly overlay virtual objects, the operator’s head position is tracked and the perspective projection matrix is calculated continuously. The necessary equations are presented. In an experimental setup, view-dependent rendering for virtual reality on opaque displays as well as augmented reality on transparent displays were validated. The rendering is performing well and an accurate overlay of virtual and real machine interior can be created. However, several difficulties regarding illumination, transparency and human stereo vision did occur. Possible improvements and solutions are suggested.