ve input devices(i) doug bowman virginia tech edited by chang song

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VE Input Devices(I) Doug Bowman Virginia Tech Edited by Chang Song

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VE Input Devices(I)

Doug Bowman

Virginia Tech

Edited by Chang Song

(C) 2005 Doug Bowman, Virginia Tech 2

Goals and Motivation

Provide practical introduction to the input devices used in VEs

Examine common and state of the art input devices look for general trends spark creativity

Advantages and disadvantages

Discuss how different input devices affect interface design

(C) 2005 Doug Bowman, Virginia Tech 3

Input devices

Hardware that allows the user to communicate with the system

Input device vs. interaction technique

Single device can implement many ITs

(C) 2005 Doug Bowman, Virginia Tech 4

Human-computer interface

SystemSoftware

Use

r in

terf

ace

soft

war

e

User

Inputdevices

Outputdevices

ITs

(C) 2005 Doug Bowman, Virginia Tech 5

Human-VE interface

Tracking system

Env. modelSimulation loop:-render-check for events-respond to events-iterate simulation-get new tracker data

Display(s)

Input device(s)

(C) 2005 Doug Bowman, Virginia Tech 6

Input device characteristics

Degrees of Freedom (DOFs) & DOF composition (integral vs. separable)

Range of reported values: discrete/continuous/hybrid

User action required: active/passive/hybrid Intended use: locator, valuator, choice, … Frame of reference: relative vs. absolute Properties sensed: position, motion, force, …

(C) 2005 Doug Bowman, Virginia Tech 7

Practical classification system

Desktop devices Keyboards, 2D mice and trackballs, pen-based tables, joysticks, 6DOF devices for the desktop

Tracking devices 3D mice Special-purpose devices Direct human input

(C) 2005 Doug Bowman, Virginia Tech 8

Desktop devices: keyboards

Chord keyboards1

Arm-mounted keyboards2

“Soft” keyboards (logical devices)

(C) 2005 Doug Bowman, Virginia Tech 9

Desktop devices: 6-DOF devices

6 DOFs without tracking

Often isometricExs: Fig. 4.4

SpaceBall 5000, SpaceMouse Plus, SpaceOrb

(C) 2005 Doug Bowman, Virginia Tech 10

Tracking Devices

Motion tracking

Eye tracking

Data Gloves

(C) 2005 Doug Bowman, Virginia Tech 14

Motion Tracking

Critical characteristics Range, latency, jitter (noise or instability), and

accuracy Different motion trackers

Magnetic Mechanical Acoustic Inertial Optical Hybrid

(C) 2005 Doug Bowman, Virginia Tech 15

Electromagnetic trackers

Exs: Polhemus Fastrak, Ascension Flock of Birds

Most common Used with conventional

monitors (for fishtank VR) Small workbench displays

Transmitter

Receiver(s)

Noisy

Affected by metal objects -> distort the magnetic field

(C) 2005 Doug Bowman, Virginia Tech 16

Inertial trackers

Inertial measurement devices : angular gyroscopes & linear accelerometer

Exs: Intersense IS-300, Intertrax2

Less noise, lag

Only 3 DOFs (orientation)

(C) 2005 Doug Bowman, Virginia Tech 17

Optical/vision-based trackers

Reflected or emitted light Exs: Vicon, HiBall, ARToolkit Advantages

accurate can capture a large volume allow for untethered tracking

Disadvantages may require light emitting

diodes(LEDs) image processing techniques occlusion problem

(C) 2005 Doug Bowman, Virginia Tech 18

Optical/vision-based trackers

Outside-in or inside-out system Sensors/landmarks – tracked

objects/environment

Setting up vision-based tracking system can be difficult

(C) 2005 Doug Bowman, Virginia Tech 19

Hybrid tracking

Ex: IS-600 / 900

inertial (orient.)

acoustic (pos.)

additional complexity, cost

(C) 2005 Doug Bowman, Virginia Tech 20

Tracking devices: eye tracking

(C) 2005 Doug Bowman, Virginia Tech 21

Tracking devices: eye tracking

User controlling a mouse pointer strictly with his eyes.

Gazed direction based

- Head-tracker as an approximation to where the user is looking. Problem can occur.

- Improve these gaze-directed techniques

(C) 2005 Doug Bowman, Virginia Tech 22

Tracking devices: bend-sensing gloves

CyberGlove7, 5DT

Reports hand posture

Gesture:single postureseries of posturesposture(s) + location or

motion

(C) 2005 Doug Bowman, Virginia Tech 23

Tracking devices: pinch gloves

Conductive cloth at fingertips

Any gesture of 2 to 10 fingers, plus combinations of gestures

> 115,000 gestures

(C) 2005 Doug Bowman, Virginia Tech 24

Case study: Pinch Gloves

Pinch gloves are designed to be a combination device (add a position tracker)

Very little has been done with Pinch Gloves in VEs - usually 1 or 2 gestures for:Object selectionTool selectionTravel

(C) 2005 Doug Bowman, Virginia Tech 25

Characteristics of Pinch Gloves

Relatively low cost

Very light

User’s hand becomes the device

User’s hand posture can change

Allow two-handed interaction

Huge number of possible gestures

(C) 2005 Doug Bowman, Virginia Tech 26

Characteristics of Pinch Gloves II

Much more reliable than data gloves

Support eyes-off input

Can diminish “Heisenberg effect”

Support context-sensitive gesture interpretation

(C) 2005 Doug Bowman, Virginia Tech 27

Pinch Gloves in SmartScene13

Lots of two-handed gesturesScale worldRotate worldTravel by “grabbing

the air”

Menu selection

(C) 2005 Doug Bowman, Virginia Tech 28

Pinch Gloves for menus

TULIP system14

ND hand selects menu, D hand selects item within menu

Limited to comfortable gestures

Visual feedback on virtual hands

(C) 2005 Doug Bowman, Virginia Tech 29

Pinch Gloves for text input

Pinch Keyboard14

Emulate QWERTY

Pinch finger to thumb to type letter under that finger

Move/rotate hands to change active letters

Visual feedback

(C) 2005 Doug Bowman, Virginia Tech 30

Combining Bend-Sensing Data and Pinch Input

Both the Pinch Gloves and bend-sensing gloves have limitations

The Flex and Pinch input system is an example of an input device that combines the functionality of the Pinch Gloves system with the bend-sensing technology of a data glove

Figure 4.15