Planning Redirection for Dynamic Passive Haptics Using Model Predictive Control

Abstract

Navigating an immersive, virtual environment (VE) is one of the key challenges when a head-mounted display is used. The most natural way of navigating a virtual environment would be walking. But walking in a large virtual environment is practically impossible unless the user is in an equally large, walkable real environment (RE), i.e. a one-to-one mapping between real and virtual worlds. A promising solution for navigating large virtual spaces in a limited real space, such as a room, is Redirected Walking.Redirected Walking (RDW) uses so-called Redirection Techniques (RETs) to guide the walker away from obstacles in the real world. These techniques modify the mapping between VE and RE depending upon user movements in real-time.Hence, a point in a real environment can be mapped to just about any point in a virtual environment at a particular time. This makes the task of redirecting the user toward an object in the real environment that serves as a proxy for an object in the virtual environment a much more complex problem. This problem ultimately boils down to creating a dynamic map between selected real and virtual world points, i.e. an entire one-to-one map between real and virtual environments is not needed. This dynamic map applies redirections not just to avoid obstacles but also to redirect the user such that whenever the user reaches for an object in the virtual world, he/she senses the proxy object in the real world.