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 occlu
sion 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 misalignmen
ts can be reduced. Our method is based on simulating the occlusion of virtu
al objects by a representation of the user modeled as kinematic chains of a
rticulated solids. Smoothing the border between virtual world and occluding
real reduces registration and modeling errors of this model. Finally, an i
mplementation in our augmented environment and the resulting improvements a
re presented. (C) 1999 Elsevier Science Ltd. All rights reserved.