Group Interaction	this work originated from the general notion that people should experience the sense of presence in a virtual space through movements as much as through visual or acoustic impressions. As social beings people are necessarily aware of their (local) position in group situations and they experience the physical space and the social climate of a group situation by simultaneously watching and moving around. In two projects we explored the modalities of group interaction between real and virtual groups or crowds. We explored the interaction patterns that are applicable in mixed-reality scenarios. project1> "Group Interaction in a Sourround Screen Environment" project2> "Responsive Body Tracking"