1. Lecture 5: Interaction and Navigation Dr. Xiangyu WANG Acknowledge the notes from Dr. Doug Bowman

2. Universal interaction tasks –Navigation Travel – motor component Wayfinding – cognitive component –Selection –Manipulation –System control

3. Selection & Manipulation –Selection: specifying one or more objects from a set –Manipulation: modifying object properties (position, orientation, scale, shape, color, texture, behavior, etc.)

4. Selection performance –Variables affecting user performance Object distance from user Object size Density of objects in area Occluders

6. Manipulation enhancements –Constraints –2-handed manipulation –Haptic feedback –Multi-modal manipulation

7. Travel –the motor component of navigation –movement between 2 locations, setting the position (and orientation) of the user’s viewpoint –the most basic and common VE interaction technique, used in almost any large-scale VE

8. You can travel techniques which do not address wayfinding, but the best travel techniques will integrate aids to wayfinding.

9. Travel tasks –Exploration: thoughtless travel techniques –Search Naïve Primed –Maneuvering: short and precise movement, usually explicit travel techniques.

10. “Natural” travel metaphors “Natural” travel metaphors: useful for training –Walking techniques –Treadmills –Bicycles –Other physical motion VMC / Magic carpet Disney’s river raft ride Simulation of flying

11. Walking techniques

12. Bicycles as Travel Technique Tang et al. 2007 (Virtual Bicycling Simulator project)

13. Bicycles as Travel Technique Images from Virtual Environments Laboratory

14. Treadmill as Travel Technique Mohler et al. 2004

15. Magic Carpet as Travel Technique Magic carpet project

16. Steering metaphor Target-based metaphor Route-planning metaphor Travel Techniques

17. Steering metaphor: continuous specification of direction of motion –gaze-directed –pointing –physical device (steering wheel, flight stick)

18. Travel Techniques Target-based metaphor –discrete specification of goal –point at object –choose from list –enter coordinates

19. Map-based travel technique (a type of Target-based metaphor) –User represented by icon on 2D map – Drag icon with stylus to new location on map –When released, viewpoint animated smoothly to new location Travel Techniques

20. Route-planning metaphor –one-time specification of path –place markers in world –move icon on map Travel Techniques

21. Steering metaphor Target-based metaphor Route-planning metaphor Steering metaphor Target-based metaphor Route-planning metaphor the relative amount of control by the user increases the relative amount of control by the system increases

22. Manipulation metaphor –manual manipulation of viewpoint –“camera in hand” Travel Techniques

23. Design guidelines –Make simple travel tasks simple (target-based techniques for motion to an object, steering techniques for search). Provide multiple travel techniques to support different travel tasks in the same application. Travel Techniques

24. Implementation issues for travel techniques –Velocity / acceleration control: Gestures, sliders, and speech control –World rotation –Constrained motion Constant height Terrain-following Travel Techniques