Combining Passive Haptics Combining Passive Haptics with Redirected Walkingwith Redirected Walking

Luv KohliLuv Kohli

Final ProjectFinal Project

COMP239 – Virtual WorldsCOMP239 – Virtual Worlds

May 25, 2005May 25, 2005

Problem 1

• Notable lack of touch feedback (haptics) in VR

• Interaction without haptics is difficult

Solutions

• Passive haptics• Active haptics• Avatar redirection

Solutions

• Passive haptics• Active haptics• Avatar redirection

Problem 2

• Size of virtual world limited by size of physical tracker space

Solutions

• Flying• Treadmills• Virtual

walkways/escalators• Redirected walking• Lots of others

Solutions

• Flying• Treadmills• Virtual

walkways/escalators• Redirected walking• Lots of others

Redirected Walking + Passive Haptics…

The idea of using passive haptics with redirected walking seemingly goes out the window

Real

VirtualPhysical prop

…with our powers combined…

With careful environment design, is it possible to incorporate passive haptics into a virtual environment that uses redirected walking?

Some thoughts

Redirected walking not possible if within arm’s reach of physical prop

Physical prop

Region whereuser is withinarm’s reachof prop

More thoughts

• Much less area available for redirecting the user

• Virtual objects must align with physical objects by the time the user reaches them

Environments to Ponder

Real Virtual

Environments to Ponder

Real Virtual

Environments to Ponder

Real Virtual

Ideal rotation point

Simplifying assumption

• Physical prop is rotationally symmetric• Allows user to approach from any

direction

Distance issue still remains

rr

d

v r

Real Virtual

d gets you everything else

• Choose d such that amount of redirection is minimized

• Can be tough to solve analytically, but might be easy numerically

Take a step back

• Find line that is equidistant from real and virtual object

• Select a point along that line to guide the user to (e.g. point closest to user)

Redirection

• When user is at point of rotation, force them to turn by using a distractor (as in Dorian Miller’s COMP239 project in Fall 2002)

• Repeat as necessary

(show Matlab)

Thieves!

• Evil flying robots have stolen several precious gems

Well…

• Okay, so they’re actually spheres.

Your goal

• Vanquish the evil flaming spheres and collect the gems for safekeeping

Teleporters

• The spheres come in through teleporters

• When a teleporter appears (and makes a sound), you must enter its beam to engage a sphere – it will appear in front of you

Hitting the spheres

• When your hand/raygun intersects a sphere, the sphere’s force field is weakened

Gems

• Hitting the spheres enough times will cause them to fade away

• Afterwards, a gem will be placed on one of five colored pedestals in the environment

• Pick up the gem by moving your hand onto it

The trick

• Spheres rotate around you while you try to vanquish them

• This forces the user to turn, and allows the system to redirect

(show log playback)

Lessons learned

• It works for a contrived case – can it be generalized at all?

• A fair amount of error is tolerable• Need a good way to plan user routes

Future work

• Make the system more robust• Do some redirection while user is

walking• Explore using a small amount of

translation to correct error

Acknowledgements

Thank you to Eric Burns, Henry Fuchs, Dorian Miller, and Sharif Razzaque for brainstorming ideas and spending a great deal of time discussing this project with me.