Occlusion in collaborative augmented environments

Augmented environments superimpose computer enhancements on the real world. Such augmented environments are well suited for collaboration of multiple users. To improve the quality and consistency of the augmentation the occlusion of real objects by computer-generated objects and vice versa has to be implemented. We present methods how this can be done for a tracked user's body and other real objects and how irritating artifacts due to misalignments can be reduced. Our method is based on simulating the occlusion of virtual objects by a representation of the user modeled as kinematic chains of articulated solids. Smoothing the border between virtual world and occluding real reduces registration and modeling errors of this model. Finally, an implementation in our augmented environment and the resulting improvements are presented. (C) 1999 Elsevier Science Ltd. All rights reserved.