Human Interaction World in miniature papers

INTERACTIVE W orlds I n M iniature WIM 1.Introduction 2.System Description 3.Findings from Previous Work 4.WIM Interaction Techniques 5.WIM Interaction Techniques 6.Visualisation & Multiple WIMS 7.Manipulating the WIM 8.Future Work Implementation Issues

Introduction World In Miniature (WIM) is a user interface What is a WIM?: –a Hand Held 3D Miniature Version of the Virtual Environment within the Virtual Environment. –addresses Real World Constraints –places the world into the users immediate reach –has the ability to allow interaction as a user interface: –Allows the selection & manipulation of objects –allows Navigation, Path Planning, Visulisation and multiple points of view

System Description A head mounted display (HMD) provides the user with an immersive point of view, with 6 degrees of freedom. A clipboard is placed in the users non dominant hand. The clip board acts as the floor and provides an aerial view. Clipboard graphics are miniature The users other hand holds a tennis ball with two buttons and a sensor built in, this is used for object selection in the WIM

Findings from Previous Work Object manipulation 1:1 mapping translations and rotations easily understood. User hands were not submersed in same physical space as graphics. 3DM only provided 1 point of view, scaling by user was disorientating Navigation (movement through 3D Space) Darken explored 2D WIM maps which since have been extended into 3D WIM Maps using a scene in hand metaphor. The NASA view took the concept and used 2D viewports to jump from one virtual environment to another. Object Selection Techniques such as Ray Casting and selection cones have been tried. The main problem with this is object occlusion.

WIM Interaction Techniques The WIM can change its point of view of the scene rapidly, this benefits the interaction allowing a quick response to occlusions. WIM fly by does not destroy point of view established. Object Selection overcoming Range and Occlusion. The object can be manipulated at different scales. Using a 3D magnifying glass the objects can be displayed at greater than 1:1 scale.

WIM Interaction Techniques Current implementation of rotating the WIM by ratcheting. Flying is the most common technique for Navigation. The ability to represent the user in the WIM. Updating after Manipulation: 1.Immediate 2.Post-Facto 3.Batch

Visualisation & Multiple WIMS Visualisation 1.Spatially locating and orientating the user 2.Path Planning 3.History 4.Measuring Distances 5.Viewing Alternative Representations Multiple WIMS Demonstrate widely Separated regions of the same environment.

Manipulating the WIM Initially didn’t use props –No haptic feedback –Users ‘contorted into uncomfortable positions’ Separately tracked clipboard and tennis ball –Easy two handed rotation –Got haptic feedback –Tennis ball allows easy 3D rotation of selected objects –Problems: Fatigue, Props get in the way.

Future Work & Implementation Issues WIM is faster at Implementation than virtual hand. Scrolling Clipping Zooming Multiple Participants 3D design for architects 2D Widgets in VR still plausible. Does not translate to CAVE system.

Paper 2 – Hands Free Multi-Scale Navigation in Virtual Environments LaViola, Feliz, Keefe, Zeleznick Presents three hands free interaction techniques in detail Discusses previous work related to navigation in Virtual Environments Translates the WIM concept from a HMD to a ‘CAVE like’ system Incorporates feet and torso movements

Other work in this area SmartScene™ Uniport & Omni-Directional Treadmill Head Directed Navigation SICS - Par Hansson / Anders Wallberg

SmartScene™ Two handed interface Using SpaceGrips™ Novices learn quickly Experts more productive than with keyboard and mouse Comfortable/Ergonomic Not wireless

Darken - Uniport (1994) Similar to Unicycle Maps physical exertion to movement Small movements difficult Direction of motion difficult to control

Darken – OmniDirectional Treadmill Mechanical Two layers of rollers interact to give motion in all directions on the floor plane Servo motors return user to centre of plane Difficult to master due to feedback problems – quick movements should be avoided Potential negative learning effect – doesn’t accurately reflect real walking

Treadmill 2

Fuhrmann (1997) – Head directed motion

Cyber Monkey! Tracker on head and hand Microphone in ear Speaker in mouth Virtual ‘guide’

The Step WIM Overview Invoking and Dismissing Scaling Locomotion by Leaning Auto Rotation Summary and future work

The Step WIM - Overview Miniature world map on the floor Use for overview or navigation Scale can be changed

The Step WIM – Invoking and Dismissing Controlled using foot gestures for invoking, scaling, dismissing Desired action indicated by current state and direction of user gaze Most natural and recognizable foot gesture: heel taps Detected using "Interaction Slippers"

The Step WIM – Invoking and Dismissing 2 Alternative interface: upward bounce Detected using a waist tracker (tethered) Monitor changes in waist height by more than 1.5" and time held for ΔhΔh

The Step WIM - Scaling Foot-based method: heel click to enter/leave scaling mode Head position projected onto Step WIM stored as centre of scale Walking changes centre of scale and WIM size Alternative interface: tip-toes/crouching

The Step WIM – Locomotion by Leaning Navigate smaller distances (in the virtual world) by leaning in desired direction Can also lean to move a larger Step WIM around Waist and head tracked, project vector between them to the floor.

The Step WIM – Locomotion by Leaning 2 More sensitive near the walls Modify speed according to head orientation: people generally focus on where they want to go => decrease speed as head tilts downwards to maintain focus

The Step WIM – Auto Rotation Allows full 360 degrees of environment to be viewed on three walls Use amplified rotation - but without causing cybersickness! Prototypes:  linear mapping counter-rotating world to head movement so that 120- >180 - caused some sickness  use torso rotation - eliminates unnatural rotation when just moving head, but still felt unnatural  non-linear mapping, used only when user has rotated beyond a threshold Combine with leaning to travel in directions originally behind the user

Razzaque – Redirecting Walking Similar to auto-rotation - but better! Takes advantage of the fact that a blindfolded person walks in an arc Subtle increases in rotations allow the environment to be imperceptibly reoriented Does not cause motion sickness!

The Step WIM – Summary Advantages:  completely hands-free, allowing easier manipulation etc.  can navigate large distances easily using the Step WIM, which can be scaled as desired  can navigate smaller distances by leaning, independent of head orientation Disadvantages:  requires belt and possibly slippers to be worn as well as headset  auto-rotation can be disorienting

The Step WIM – Possible Developments Modify to use only head tracking (and perhaps slippers) Improve leaning detection by putting pressure sensors in slippers Additional hands-free controls Include walking in place technique, speech recognition

WIM Overall Conclusions Multiple points of view Multiple scales Easy selection at a distance Easy to learn Easy to travel long distances Not suitable for all applications (medical)