An Optical See-Through Mixed Reality Display with a Realtime Range finder and an Active Pattern Light Source

Abstract

Mixed Reality (MR) conjuncts the real world with a virtual world created by a computer. Optical superimposing has been a promising MR displaying technology so that it does not degrade the quality of the user's view. Unfortunately, optical see-through displays can not represent correct occlusion phenomenon; a CG object can not occlude a real object, but overlaps on the real one translucently. In this paper an architecture of an optical see-through MR display, which solves the above problem, is proposed. It can represent correct occlusion phenomenon among the real and virtual objects. Two types of new prerequisite elements, a realtime range finder and an active pattern light source with a video projector, are involved into the display. The dynamic active pattern light projection illuminates only not occluded portions of the real object in darkroom, according to the interference among 3D models of the virtual object and real one which is acquired by the range finder. Therefore, the occluded portions of the real object is not visible due to no illumination; the CG object occludes the real object approximately. A prototype display based on the architecture shows us interesting interactions between the virtual world and the real world including user's hand operations.