1. Perspectives, Frame Rates and Resolutions: It's all in the Game Mark Claypool Kajal Claypool Worcester Polytechnic Institute Worcester, MA, USA http://www.cs.wpi.edu/~claypool/papers/perspective/ MIT Lincoln Labs Lexington, MA, USA

2. Computer Games and Performance Latest computer games push capabilities of hardware in “quest” for more detailed, realistic graphics Single game runs on varied hardware –PC : Old (600 MHz P3, 32 MB Video) or New (4 GHz P4, 512 MB Vid) –Platform: PC, Console (i.e. Xbox), Hand-held (i.e. PSP) –Result: Uneven hardware capabilities, opportunities for performance tuning Key factors for game performance are: –Frame Rate – higher frame look smoother, provide more temporally precise feedback –Frame Resolution – higher resolutions look better, provide more visually precise feedback 2FDG, Orlando, FL, USA

3. Motivation Unfortunately, often cannot have both high Frame Rate and high Frame Resolution –Ex: Hand-held devices have constrained resources (small screens, limited power) –Ex: Older computers (often, only 1 year!) cannot run latest games at maximum frame rate or resolution Tradeoff between Frame Rate and Frame Resolution –Higher resolutions mean lower frame rates and vice versa How are frame rates and resolutions chosen? –Game console designers and hand-held designers choose resolution for user Frame rate may depend upon processing load –PC gamers choose it by “feel” –Can we guide by science? 3FDG, Orlando, FL, USA

4. Related Studies Passive Users [1,10,12,20,22,24,25] –Users assess video with various frame rates and resolutions –Generally, decrease resolution decreases perceived quality, but decrease in frame rate less so Active Users [14,15,16,18,23] –Users perform tasks under various frame rates and frame resolutions –Generally, extremely low frame rates impact performance, but frame rates of 5+ acceptable Games [3,5] –Different than video: frame rate matters, not resolution –But First Person Shooters only Our goal – Effects of Frame Rate and Frame Resolution on User Performance for Games 4FDG, Orlando, FL, USA

5. Effects of Frame Rate and Resolution Impact of frame rate and resolution depends upon action in the game –Consider fundamental actions: shooting and navigating Hypotheses 1.Shooting greatly impacted by frame rate 2.Navigating less impacted by frame rate 3.Resolution has little impact on player performance 4.1-3 hold across game genres based on camera perspectives FDG, Orlando, FL, USA5

6. Outline Introduction(done) Game Perspectives(next) Approach Results Conclusions FDG, Orlando, FL, USA6

7. Game Perspectives Based on: –placement of camera with respect to the avatar –visual change in object sizes relative to camera FDG, Orlando, FL, USA7 First Person Linear Third Person Linear Third Person Isometric

8. Methodology Develop games Build test harness Setup environment Solicit users Analyze results Disseminate (this talk ) FDG, Orlando, FL, USA8

9. Game Development Implementation using Game Maker w/stock art Three games (1 st, 3 rd linear, 3 rd isometric) Two levels (navigating and shooting) for each game Normalized so rates of shooting and navigating same across genres FDG, Orlando, FL, USA9 Third Person Isometric Third Person Linear First Person Linear

10. Test Harness In Visual Basic Tutorials on navigation level, shooting level 36 game sessions (3 perspectives, 4 frame rates, 3 resolutions) –15 seconds each session –Took ~15 minutes total Questionnaire at end of each session FDG, Orlando, FL, USA10

11. Experiment Environment Campus computer lab Dell Precision 380 Computers –Pentium D 3.0 GHz Dual Core –Dell 1907 Flat Panel displays –2 GB of RAM –Monitor resolution 1280x1024 pixels Users kept at least one computer apart –Reduce distraction from adjacent people. FDG, Orlando, FL, USA11

12. User Solicitation Flyers posted around campus Oral announcements in courses Email to various student groups Enticed with: –Raffles for $25 Best Buy gift certificates –Extra credit for select academic courses FDG, Orlando, FL, USA12

13. Outline Introduction(done) Game Perspectives(done) Approach(done) Results(next) –Demographics –Navigating –Shooting –Perception Conclusions FDG, Orlando, FL, USA13

14. User Demographics 27 users Most CS undergraduates 89% male 74% 16-25 years 60% played 6+ hours of games per week –Time correlated with user performance 25% casual gamers 50% hardcore or almost hardcore FDG, Orlando, FL, USA14

15. Navigating versus Frame Rate Distinct trendlines  suggests 3 rd isometric easiest Slight increase with frame rate for 1 st and 3 rd linear FDG, Orlando, FL, USA15

16. Navigating versus Resolution Distinct trendlines FDG, Orlando, FL, USA16 Flat with resolution

17. Shooting versus Frame Rate 3 rd isometric highest, easiest to locate target 1 st and 3 rd linear overlap “Knee” at 15 f/s (7 f/s unplayable for 1 st and 3 rd linear) FDG, Orlando, FL, USA17

18. Shooting versus Resolution FDG, Orlando, FL, USA18 Distinct 3 rd iso Flat with resolution

19. Playability and Quality FDG, Orlando, FL, USA19

20. Conclusions Frame Rate larger impact on performance than Resolution –Frame Rate critical for adequate game performance Marked drop in performance below 15 fps –Resolution has little effect on user performance Users as effective from 800x600 to 1280x1024 –Holds across all perspectives and actions Frame Rate and Resolution both important for user perception –Playability mirrors frame rate –Quality slight upward trend with resolution Dramatically different previous research on video –Showed converse, that Resolution mattered more –Suggests challenges in designing devices for games and video FDG, Orlando, FL, USA20

21. Perspectives, Frame Rates and Resolutions: It's all in the Game Mark Claypool Kajal Claypool Worcester Polytechnic Institute Worcester, MA, USA http://www.cs.wpi.edu/~claypool/papers/perspective/ MIT Lincoln Labs Lexington, MA, USA