1. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 1 Redirected Touching Eric Burns Comp 239 Nov. 7, 2002

2. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 2 There is a problem with current Virtual Environments Users are not stopped from moving through virtual objects This creates a break in presence It also creates a problem with physical simulations

3. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 3 I propose a method to reduce these effects We should not allow the user’s avatar hand to penetrate solid objects. (although his or her real hand does)

4. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 4 Come on... hasn’t anybody done that before? Yes

5. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 5 So... what you’re doing is special because.... This method creates another problem. Once a user’s real and virtual hand have become separated, how do we rejoin them? One method is to leave the virtual hand where it is until the real hand is no longer penetrating an object. Then pop them back together.

6. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 6 This method causes a break in presence for two reasons 1.When the user moves his or her real hand, he or she expects to see the virtual hand move. If it is frozen in place, the user is reminded it is not his or her real hand. 2.When the hand pops to its real location the user is reminded he or she is in a virtual world. In the real world my hand doesn’t pop anywhere.

7. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 7 I propose another method for rejoining the hands When the user’s hands become disjoined, still have the virtual hand respond to the actions of the user as much as possible. When we become able to reduce the distance between the real and virtual hands, we do so. However, we do so slowly, in such a way that hopefully the user will not notice the hand behaving oddly

8. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 8 Here are some pictures demonstrating what I just said

9. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 9 What can we take advantage of? While user is still, motion of virtual hand will be imperceptibly slow While user is moving his or her head, we can speed up the motion of the hand While the user is moving his or her hand, we can also speed up the motion

10. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 10 Why can we do this? Proprioception is most sensitive to high frequency movement In other cases, we rely on other cues (for example, visual or tactile). For low frequency motion, if the various cues we receive are in conflict, our visual system dominates Therefore, by controlling the user’s visual input, I propose that we could have the user be unaware that his or her hand is in the wrong place

11. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 11 To summarize everything.... I propose a method for redirecting an avatar’s location in order to reduce breaks in presence and preserve the rules in physical simulations

12. The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL 12 Special Thanks to: Henry Fuchs Sharif Razzaque Ming Lin Harald Schmidl Paul Zimmons Thorsten Scheuerman Dorian Miller Jason Jerald Greg Coomb Chris Oates