1. Regis Kopper Mara G. Silva Ryan P. McMahan Doug A. Bowman

2. Large high resolution displays are becoming cheap and common New interaction styles are needed Traditional mouse isnt enough Enhanced mouse techniques Enhance target size and activation area E.g. Bubble cursor Mouse acceleration

3. New interaction styles are needed Even with enhancements, mouse may not be enough Slow (clutching) Single user Affords to sit at a fixed position, rather than walking Distant pointing as alternative Laser pointer metaphor Affords to stand and physically move across the display Absolute (rapid) target acquisition, no clutching But it still has problems…

4. One of the fundamental classes of 3D Interaction Ray-casting as a common and simple implementation User points with a virtual ray extending from the input device For large displays, intersection of ray with display determines cursor position Freedom to move around Rapid movements to any point in the display Lack of precision makes it impractical (small targets)

5. Precision issues Natural hand tremor Heisenberg effect Mapping varies with distance No Parkability No supporting surface

6. Basic Enhancements Increased cursor size Visible to the user from greater distances Low-pass filter Dynamic recursive filter to eliminate low frequency tracking jitter and hand tremor Framing Movement of virtual ray when click occurs is ignored and position at beginning of click is used

7. Absolute and Relative Mapping (ARM) Ray- casting Bimanual technique Dominant hand controls cursor Non-dominant hand controls mapping mode

8. Absolute and Relative Mapping (ARM) Ray- casting Scale factor determines relative area mapped from absolute pointing Offers increased precision In this study, S=0.1 was used Most effective when relative mode is not overused Only needed when high precision is desired Offers high-precision pointing, but does not improve visual perception

9. Zoom for Enhanced Large Display Acuity (ZELDA) Bimanual technique Dominant hand controls the cursor Non-dominant hand controls a zoom window Main idea: Magnified view which not only improves precision, but enhances visual acuity

10. Zoom for Enhanced Large Display Acuity (ZELDA) Zoom window When moving, small rectangle indicates zoomable area When frozen, area underneath its center is zoomed in by a zoom factor Zoom factor controlled by a scroll wheel When pointing to the sides or up/down, zoom window can be resized Many strategies possible Selection Placement

11. Video

12. Conducted to evaluate two aspects Do ARM and ZELDA increase precision compared to basic ray-casting, when strategy does not play a role? Strategy controlled by application Atomic tasks How do ARM and ZELDA afford strategies that improve performance in realistic tasks? Users freely used the techniques Complex tasks Selection Placement

13. Experimental design Atomic tasks Selection and placement subtasks Independent variables Icon radius (selection) Effective target size (placement) Amplitude Distance to display Technique

14. Experimental design Atomic tasks Dependent variables Number of errors Time 3 (I) x 2 (A) x 2 (D) x 3 (T) within subjects design T varying between subjects for ZELDA and ARM conditions 5 measures per subject per condition Average used in the analysis

15. Experimental design Complex tasks Independent variable: Technique ARM Ray-casting and ZELDA, compared to basic Ray- casting Selection and placement tasks Dependent variables Time to complete the task Strategies used

16. Gigapixel Display Vicon tracking system Wireless mice with markers

17. Atomic tasks ZELDA: zoom window was placed over the icon or the target ARM Ray-casting: threshold indicating the beginning of relative mode placed under the icon or target Guided practice

18. Complex tasks Desktop-like interaction metaphor Subjects performed either ZELDA or ARM and basic ray-casting Guided tutorial Learn basic ray-casting and technique Think different strategies Two types of tasks Selection (easy, medium and difficult) Placement (easy, medium and difficult)

19. Complex selection task Complex placement task

20. Atomic tasks

21. ARM and ZELDA contained significantly less errors than basic ray-casting Findings provide evidence that both ZELDA and ARM are indeed more precise than basic ray-casting and are most helpful for the hardest tasks Comparing ARM with ZELDA it was found that ARM was significantly more precise for the hardest placement tasks ARM scale factor of ARM was bigger than ZELDA zoom factors

22. Results Complex tasks Variance was too large to result in any statistically significant results

23. Complex tasks Video analysis of strategies Most subjects preferred to maintain a distance to the display 11 out of 16 subjects walked less using ARM or ZELDA than using basic raycasting The high-precision techniques improved performance among all the walking strategies employed by the subjects ZELDA resulted in a larger zoom window set up time, thus increasing overall performance time Subjects used relative mode for almost all interactions using ARM Direct and simple to activate

24. In realistic tasks, using a good strategy is as important as using a high-precision technique Basic raycasting may be enough for not very precise tasks ARM raycasting provides little overhead, and could be used in most tasks without hurting performance Due to its complexity, users who performed better with ZELDA were the ones who minimized zoom window operations

25. ZELDA and ARM are complementary and could be combined into a single technique Naïve way: Provide one more button in the zoom window controlled Too complex More intelligent ways should be sought For example, popping up a zoom window every time relative mode is activated Overall, ZELDA and ARM allow users to be lazy both in terms of pointing accuracy and physical navigation, while maintaining precision and efficiency; basic raycasting can be as precise in most cases, but require users to work harder

26. Its feasible to have 3D interaction with 2D data and it is possible to increase precision For future work, a combined technique should be sought We believe that there are models of human motor behavior that allow the prediction of performance according to different strategies Such models could offer guidelines for effective distant pointing techniques for large high-resolution displays