Stencil Buffer Implementation of Impossible Spaces
One of the biggest challenges in virtual reality is locomotion. The best way to experience virtual reality is through natural walking. However, virtual worlds are often much larger than the physical environments we have to explore them, so the user’s locomotion in the virtual world is limited by the constraints of the physical world. Common solutions to this problem all have major drawbacks. For example, virtual locomotion causes cybersickness and reduces the user’s sense of presence. A technique called impossible spaces solves this problem by designing virtual environments that overlap, allowing a point in physical space to be mapped to more than one point in virtual space. However, the original implementation of using triggers to change the geometry of the environment has limitations. It requires careful setup and planning so the transitions are unnoticeable. In this project, we propose a new implementation technique using stencil buffers to render only the room the user is in and any rooms visible through doorways. This new technique allows for a simple drag-and-drop approach for fast level design and makes designing a variety of impossible spaces easier. Additionally, we have developed several sample environment layouts to demonstrate the usage of this technique.