Tethering and Reattachment in Collaborative Virtual Environments

Our purpose is to explore a family of specific dynamical methods that support the contrasting goals of presence and independence in collaborative virtual environments. We pose for ourselves the basic tasks of “tethering” — keeping a collaborator close to a group or leader, and of “reattachment” — returning to a collaborative virtual activity after a period of independent exploration. We first present a taxonomy of parameters covering a wide variety of basic, physically-motivated, “look-and-feel” actions associated with tethering and reattachment; these range from elasticity functions and distance ranges to variations of ease-in/ease-out styles of interpolative movements. Exploiting our previous research on constrained navigation, we contrast reattachment methods based on free flight with structured motion along a detailed constraint surface, and with comparable motion on smoother overview constraint surfaces. The system is implemented with full head tracking and pointer tracking using the Performer and pfCAVE libraries, and is realized via simulation in four different environments: fully immersive, head mount, desk, and workstation.