1. 3DUI – Submission #120
LOP-cursor Fast and Precise Interaction with Tiled Displays Using One Hand and Levels of Precision
Henrique Debarba, Luciana Nedel,Anderson Maciel
Federal University of Rio Grande do Sul (UFRGS)
Institute of Informatics (INF)

2. Contributions Levels of Precision Cursor (LOP-cursor)
Technique for high precision and fast pointing
Two-legged cursor metaphor
Simultaneous control over 2 cursors

3. Introduction LOP-cursor Evaluation Conclusion -Motivation
-Related Work
LOP-cursor
-LOP-cursor technique
-two-legged cursor
Evaluation
-Comparative
-In depth LOP
Conclusion
-Conclusions
-Future works

4. Motivation Large and very high resolution displays Mobile Devices
Usefull
Are becomming cheaper
Ordinary interaction techniques may not be adequate
Mobile Devices
First computational device really pervasive (Ballagas 2006)
Equiped with a wide range of sensors and displays
Very popular

5. Motivation
at&t

6. Motivation
Operations Centre of Rio de Janeiro

7. Motivation Large and very high resolution displays Mobile Devices
Usefull
Are becomming cheaper
Ordinary interaction techniques may not be adequate
Mobile Devices
First computational device really pervasive (Ballagas 2006)
Equiped with a wide range of sensors and displays
Very popular

8. Motivation
BIG TV AMD eyefinity

9. Motivation Large and very high resolution displays Mobile Devices
Usefull
Are becomming cheaper
Ordinary interaction techniques may not be adequate
Mobile Devices
First computational device really pervasive (Ballagas 2006)
Equiped with a wide range of sensors and displays
Very popular

10. Motivation Large and very high resolution displays Mobile Devices
Usefull
Are becomming cheaper
Ordinary interaction techniques may not be adequate
Mobile Devices
First computational device really pervasive (Ballagas 2006)
Equiped with a wide range of sensors and displays
Very popular

11. Motivation Large and very high resolution displays Mobile Devices
Usefull
Are becomming cheaper
Ordinary interaction techniques may not be adequate
Mobile Devices
First computational device really pervasive (Ballagas 2006)
Equiped with a wide range of sensors and displays
Very popular

12. Motivation Large and very high resolution displays Mobile Devices
Usefull
Are becomming cheaper
Ordinary interaction techniques may not be adequate
Mobile Devices
First computational device really pervasive (Ballagas 2006)
Equiped with a wide range of sensors and displays
Very popular

13. Motivation
There are more registered cellphone lines than inhabitants in Brazil (over 200 Million)

14. Related Work Pointing using optical flow
Sweep (Ballagas et al, 2005)
Interaction techniques in large display environments using hand-held devices (Jeon et al, 2006)
Pointing using pattern recognition
Point & Shoot (Ballagas et al, 2005)
Touch projector (Boring et al, 2010 and 2011)
Pointing using external tracking of the device
Lightsense (Olwal, 2006)

15. Related Work Pointing with levels of precision
Hybridpointing (Forlines et al, 2006)
ARC-pad (McCallum and Irani, 2009)

16. LOP-cursor shapes Rectangle/Control canvas Mobile Device Touchscreen
Ring
Leg 2 Cursor
Arrow
Leg 1 Cursor
Line
Connects Rectangle and Ring

17. LOP-cursor shapes

18. Overview Levels of Precision Cursor (LOP-cursor) 2-Leg cursor metaphor
First Level
Rough pointing
RayCasting
Second Level
Precise pointing
Touchscreen

19. Overview Levels of Precision Cursor (LOP-cursor) 2-Leg cursor metaphor
First Level
Rough pointing
RayCasting
Second Level
Precise pointing
Touchscreen

20. Overview Levels of Precision Cursor (LOP-cursor) 2 Leg cursor metaphor
First Level
Rough pointing
RayCasting
Second Level
Precise pointing
Touchscreen

21. Overview Levels of Precision Cursor (LOP-cursor) 2-Leg cursor metaphor
First Level
Rough pointing
RayCasting
Second Level
Precise pointing
Touchscreen

22. Overview Levels of Precision Cursor (LOP-cursor) 2 Leg cursor metaphor
First Level
Rough pointing
RayCasting
Second Level
Precise pointing
Touchscreen

23. 3 STATES 1 Free-pointing 2 3 Hold-control-canvas + Free-pointing
Pin-control-canvas + Free-pointing

24. 3 STATES - Free-pointing1
Free-pointing

25. 3 STATES - Hold-control-canvas2
Hold-control-canvas + Free-pointing

26. 3 STATES - Pin-control-canvas
Pin-control-canvas + Free-pointing

27. Pinch/Stretch to rescale
reduce size
Stretch
Increase size

28. Selection
But, how can I trigger a selection if touch screen is being used for pointing?

29. Selection Method
Click on the back of the device

30. Device orientation
Obtained using Gyroscope, Accelerometer and Magnetometer.
Gyro – rate of change in three axis
Acc. – corrects drift around X and Z
Mag. – corrects drift around Y
Sensors fusion (Madgwick et al, 2011)
Magnetometer correction z y x
ADD slide - redundancia

31. Device Position Fixed position Calibration rather than tracking
Omitir??

32. Evaluation Comparative evaluation In depth LOP-cursor evaluation
Orientation RayCasting vs ARC pad vs Constrained LOP-cursor
Additional test with unconstrained LOP-cursor
In depth LOP-cursor evaluation
Task 1 – point and select
Task 2 – point, select, drag and dock
Task 3 – 2-legged classification

33. Evaluation Comparative evaluation In depth LOP-cursor evaluation
Orientation RayCasting vs ARC pad vs Constrained LOP-cursor
Additional test with unconstrained LOP-cursor
In depth LOP-cursor evaluation
Task 1 – point and select
Task 2 – point, select, drag and dock
Task 3 – 2-legged classification

34. Evaluation Comparative evaluation In depth LOP-cursor evaluation
Orientation RayCasting vs ARC pad vs Constrained LOP-cursor
Additional test with unconstrained LOP-cursor
In depth LOP-cursor evaluation
Task 1 – point and select
Task 2 – point, select, drag and dock
Task 3 – 2-legged classification

35. Comparative Evaluation
ORayCasting

36. Evaluation Comparative evaluation In depth LOP-cursor evaluation
Orientation RayCasting vs ARC pad vs Constrained LOP-cursor
Additional test with unconstrained LOP-cursor
In depth LOP-cursor evaluation
Task 1 – point and select
Task 2 – point, select, drag and dock
Task 3 – 2-legged classification

37. Comparative Evaluation
ARC pad
Dizer q eh nossa implementacao referenciar
McCallum and Irani, UIST 2009

38. Comparative Evaluation
Our implementation of the ARC pad

39. Evaluation Comparative evaluation In depth LOP-cursor evaluation
Orientation RayCasting vs ARC pad vs Constrained LOP-cursor
Additional test with unconstrained LOP-cursor
In depth LOP-cursor evaluation
Task 1 – point and select
Task 2 – point, select, drag and dock
Task 3 – 2-legged classification

40. Comparative Evaluation
CLOP-cursor
Comentar que eu soh estou mostrando que temq clicar em baixo

41. Evaluation Comparative evaluation In depth LOP-cursor evaluation
Orientation RayCasting vs ARC pad vs Constrained LOP-cursor
Additional test with unconstrained LOP-cursor
In depth LOP-cursor evaluation
Task 1 – point and select
Task 2 – point, select, drag and dock
Task 3 – 2-legged classification

42. Comparative Evaluation
LOP-cursor

43. Comparative Evaluation
Experiment design
Within subject
3 Techniques - Counterbalanced
Orientation RayCasting vs ARC pad vs Constrained LOP-cursor
4 Target sizes – 1 – 2 – 4 – 8 cm
11 participants
Interacting 150 cm away from the display
Asked to favor accuracy over time
LOP-cursor additional evaluation
6 Target sizes – 0.5 – 1 – 2 – 4 – 8 – 16 cm
8 participants

44. Comparative Evaluation
Error rate
Mean time

45. LOP-cursor Aditional Evaluation
LOP-cursor - LOP-First level and LOP-Second level
User preference for each size
Error rate

46. Comparative Evaluation
LOP-cursor
Preferred by 7 users
ARC pad
Preferred by 1 user

47. In depth LOP-cursor evaluation
Design
3 tasks
Task 1 – point and select
Task 2 – point, select, drag and dock
Task 3 – 2-legged classification
4 target sizes – 0.3 – 0.8 – 2 – 4 cm
11 participants
Interacting 150 cm away from the display
Asked to favor accuracy over time

48. Task 1 - Selection

49. Task 2 - Select + Drag + Dock

50. Task 3 - Two-legged classification

51. Results Mean time System Usability Scale (SUS) questionnaire
Scored SD 12.8

52. Conclusions
Ordinary smartphones are valuable gestural input devices to interact with large and high resolution displays
Defining a raw position with raycasting, and than a fine tune with touch input allows fast and precise interaction on selection and docking tasks

53. FUTURE WORKS Control over multiple computers
investigate 2-legged metaphor
Are users able to use cursors simultaneously?
How detrimental to interaction is attention switch between cursors?
Which tasks may benefit from the use of the 2-legged cursor?

54. Screen Replication

55. 3D selection

56. !
Thank you

57. ?
Questions

58. Offset

59. Offset

60. Offset

61. Offset

62. Pinch/Stretch to zoom in/out
zoom out

63. Assess limitations of position calibration
How detrimental to the user experience is the use of a calibrated position?
How much can users move away from calibrated position without significantly affect pointing performance?
Tirar

64. Device Position Fixed position Calibration rather than tracking 2 1
Omitir?? 1

65. Device Orientation Magnetometer correction Projecting on XZ plane
Redundancy control
Magnetometer is updated only when
gyroscope confirms that a rotation change
actually occurred z y x