Mutual occlusions on table-top displays in mixed reality applications

This paper describes an approach to dealing with mutual occlusions between virtual and real objects on a table-top display. Display tables use stereoscopy to make virtual content appear to exist in 3 dimensions on or above a table top. The actual image, however, lies on the physical plane of the display table. Any real physical object introduced above this plane therefore obstructs our view of the display surface and disrupts the illusion of the virtual scene. The occlusions result between real objects and the display surface, not between real objects and virtual objects. For the same reason virtual objects cannot occlude real ones. Our approach uses an additional projector located near the user's head to project those parts of virtual objects that should occlude real ones directly onto the real objects. We describe possible applications and limitations of the approach and its current implementation. Despite its limitations, we believe that the proposed approach can significantly improve interaction quality and performance for mixed reality scenarios.

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