Interaction in Virtual Reality Jesper Kjeldskov CVMT

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Interaction in Virtual Reality Jesper
KjeldskovCVMT
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briefly about myself

• Cand. mag. in humanistisk informatik
• Thesis (99-2000) mixed reality as
  interfaceparadigm for CSCW
• Research assistant for ½ year working with
  interaction in VR
• Ph.D. student 1/9 design and usability of mobile
  interfaces VR on the road?

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This session

• Introduction to the area of VR interaction
• Experienced problems in relation to interaction
  in VR
• Alternative solutions
• Advantages
• Disadvantages

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Myths of interaction i VR

• There exist one optimal interaction technique
  for virtual reality
• Different displaytypes should always use the
  same interaction technique

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Reality
A good interaction technique depends on the
relations between

• Inputdevices
• Display type
• Application context
• Type of application
• Users skills
• Etc.

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Desktopdevices
Spaceball/Spacemouse
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Positiontrackers
Electromagnetic (Polhemus, Assension osv.)
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Positiontrackere
Computervision
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Combined devices
Wanda, TrackMan
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Gloves
CyberGlove, 5dt glove
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Interactiondevices of tomorrow?
brainfingers
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Display types
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Categorizing display types

• Full immersive displays
• 6-sided CAVEs
• Head mounted displays (HMDs)
• BOOMs (HMD mounted on stand)
• 2) Partial immersive displays
• 3-5 sides CAVEs
• Panorama, Powerwalls
• Monitors

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Creating interaction for VR

• Based on a 6-month project during 2000
• Dividing the concept of interaction
• Orientation
• Navigation
• Manipulation
• selection/picking
• systemcontrol

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Orientation in VR

• being able to look around in a virtuel
  environment developing a sense of presence

• Available field of view
• Full immersive displays
• Display concepts has build-in support for
  orientation
• Partial immersive displays
• Display concepts has build-in limits for
  orientation

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Creating orientation

• 3 examples (Panorama)

• Joystick/trackball
• Headtracking (hypersensitive)
• Headtracking (with zones)

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Joystick/trackball

• The user rotates in the virtual world by moving
  the joystick/trackball from side to side

• Advantages easy to use gets the job done
• Disdvantages having to use an extra device
• Joystick best for fast/continuous movements
• Trackball best for precise/absolute movements
• Trackball greater feeling of control

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Headtracking (hypersensitive)

• The users rotation is enhanced, making it
  possible to view 360º within rotation of 160º

• Advantages
• No extra device, easy to use, makes it posible to
  do very fast movements (useful in eg. Quake)
• Disadvantages
• Hard to gain a feeling of pressence, easy to
  loose ones orientation in the virtuel world ?

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Headtracking (with zones)

• When the user looks towards the edge of the
  screen the virtual world rotates in that direction

• Advantages
• No extra device, easy to use, preserves ones
  feeling of orientation
• Disadvantages
• Limits the freedom of movement creates a
  conflict between orientation in the physical and
  the virtual world

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Navigation i VR

• being able to move/find ones way through a
  virtual world

• To a large extend a question of app. context
• Virtuel worlds (inside-out) vs. virtuel objects
  (outside-in)
• Visualizations/simulations vs. eg. art, games,
  etc.

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Creating navigation

• 3 examples (CAVE/Panorama)

• Joystick with 6DOF tracking
• Trackball with 6DOF tracking
• Navigation zones

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Joystick with 6DOF tracking

• The user flyes in the direction he moves the
  joystick.

• Advantages
• Easy to learn, easy to use. Large freedom of
  movement
• Disadvantages
• The joystick is not suited for both fast and
  precise movements has a need of more gears
• The implementation uses both directions on
  joystick
• the joystick is best suited for continuous
  movements

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Trackball with 6DOF tracking

• The user flyes in the direction he moves the
  trackball

• Advantages
• Easy to learn, easy to use. Large freedom of
  movement
• Small movements greater feeling of control
• Disadvantages
• The trackball is not suited for flying long
  distances
• The implementation uses both directions on
  trackball
• the trackball is best suited for absolute
  movements

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Navigation zones

• The user is surrounded by a number of virtual
  zones. By pointing with his hand the user
  activates different navigation modes

• Advantages
• No extra devices, no need for buttonpresses
• Easy to combine with manipulation
• Disadvantages
• Limits freedom of movement
• Can be hard to comprehend

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Manipulation i VR

• Two primary approaches
• Simple virtual hand
• Ray-casting (virtuel laserbeam)

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The virtual hand approach

• The users hand is represented in VR using
  positiontracking

• Advantages
• Very natural and easy to learn
• Easy to rotate and position objects
• Disadvantages
• Limited area of manipulation

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The ray casting approach

• The user interacts using a virtual laserbeam
  pointing from the inputdevice or physical hand

• Advantages
• Objects at a distance can be selected/picked
• (also) very natural and easy to learn
• Disadvantages
• Ineffective for selecting small objects at a long
  distance
• Not good for rotating and positioning objects

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An in between solution?

• The go-go hand (Poupyrev et al.) The virtual
  hand is not liniar, but lets user stretch his
  virtual arm for selection/manipulation of objects
  far away

• Advantages
• Allows manipulation in a large range of distances
• Disadvantages
• Range is still limited, interaction is not natural

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Creating manipulation

• 3 examples (CAVE/Panorama)

• Selecting/picking by touching
• Selecting/picking using buttonpresses
• Using gloves

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Picking by touching

• The user selects objects for manipulation by
  touching them

• Advantages
• No need for buttons (works with eg.
  computervision)
• Disadvantages
• Question how to drop selected objects?
• Constrained objects (handles, levers etc.)
• Not constrained objects (torches, tools etc.)

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Picking using buttonpresses

• The user selects objects for manipulation by
  touching them AND pressing a button

• Advantages
• Clear indication of intended interaction
• Easy to use (also for the ray casting approach)
• Disadvantages
• None but having to use a physical device

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Using gloves

• The user selects objects for manipulation using
  gestures (eg. touching closing hand)

• Advantages
• Perhaps more natural ? (but is that always
  better?)
• Gloves are (can be) comfortable and easy to use
• Disadvantages
• No clear distinction between interacting in
  physical or virtual world

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Combining interaction modes

• Optimize combinations
• Devices, display, context
• Implementation of devices
• Orientation
• Navitagion
• Manipulation

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Conclusions

• There is NOT one optimal way to design
  interaction for virtual reality
• Optimal interaction techniques is dependant of
  the type of display used
• Solution not trivial
• Hard work
• Creativity
• Usability tests