1. The Effects of Frame Rate and Resolution on Users Playing First Person Shooter Games Mark Claypool CS Department Worcester Polytechnic Institute http://www.cs.wpi.edu/~claypool/papers/fr-rez/ Kajal Claypool Feissal Dama CS Department University of Massachusetts, Lowell

2. January 2006 MMCN, San Jose, California2 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 (3 GHz P4, 256 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

3. January 2006 MMCN, San Jose, California3 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” –Not guided by science

4. January 2006 MMCN, San Jose, California4 Related Studies Passive Users [1,2,3,4,5,6,7] –Users assess video with various frame rates and resolutions –Generally, decrease resolution then decrease quality, but decrease in frame rate less so Active Users [8,9,10,11] –Users perform tasks under various frame rates and frame resolutions –Generally, extremely low frame rates impact performance, but frame rates of 4+ can be acceptable Overall - more passive than most games and tradeoffs not compared Our goal – Effects of Frame Rate and Frame Resolution on User Performance for Games

5. January 2006 MMCN, San Jose, California5 Outline Introduction(done) Methodology(next) Results What’s Going On? Conclusions

6. January 2006 MMCN, San Jose, California6 Methodology Outline Select game Build custom map Select parameters Build test harness Solicit users Analyze results

7. January 2006 MMCN, San Jose, California7 Methodology – Select Game First Person Shooter (FPS) –Popular genre, especially for online play –Requires intense player interaction with time-critical decisions Impairment to the display quality can cost virtual lives Quake III Arena –Still fairly popular (~700 active servers via GameSpy) –Representative of current FPS games in terms of perspective, weapon choices and gameplay –Allows control of frame rate and resolution at startup

8. January 2006 MMCN, San Jose, California8 Methodology – Custom Map = spawn point Opponent Platform (Chasm) User Platform Minimize effects of other players –Use Bot (Xaero) Minimize movement –Chasm cannot be jumped –Wall behind player so doesn’t fall off accidentally Maximize aiming and shooting –No cover (save wall to protect spawn point) –Use of railgun that cannot be rapidly fired –One shot per kill

9. January 2006 MMCN, San Jose, California9 Frame rate: 30, Resolution: 640x480 Example

10. January 2006 MMCN, San Jose, California10 Methodology – Demographics Demographics provided once, before maps started

11. January 2006 MMCN, San Jose, California11 Methodology – User Perception User perception provided after each map played

12. January 2006 MMCN, San Jose, California12 Methodology – Parameters 5 frame rates: 3, 7, 15, 30 and 60 fps –Ranges previously studied –May appear during normal game play 3 frame resolutions: 320×240, 512×384, 640×480 –Hand-held devices to low-end PCs –Observed trend may interpolate to higher resolutions

13. January 2006 MMCN, San Jose, California13 Methodology –Test Harness For each player … Gather demographics Play Quake III –Very high frame rate (80 fps) –Very high frame resolution (1024×768 pixels) Shuffle (Frame Rate, Frame Resolution) combos For each combo … –Play Quake III with (Frame rate X, Resolution Y) –Gather user perception

14. January 2006 MMCN, San Jose, California14 Methodology – User Solicitation Two-week period Game played on isolated PC in lab Range of enticements: –Enter raffle for three $50 gift certificates –Extra credit for courses –Refreshments for participants

15. January 2006 MMCN, San Jose, California15 Outline Introduction(done) Methodology(done) Results(next) What’s Going On? Conclusions

16. January 2006 MMCN, San Jose, California16 Aggregate Statistics 60 users provided “clean data” –64 participated, but 4 removed because ended early Age: –Most (~75%) 16-25 years old (ugrad CS students) –Almost 25% over 25 years old (grad CS students) Gaming: –Over 65% played games over 1 hour per week –25% played 6+ hours per week –50% casual gamers, moderate at shooters Gender: –About 20% female Only one more than casual gamer, compared to about 65% for males

17. January 2006 MMCN, San Jose, California17 Performance and Frame Rate (Resolution: 512x384 pixels)

18. January 2006 MMCN, San Jose, California18 Performance and Frame Resolution (Frame Rate: 15 fps)

19. January 2006 MMCN, San Jose, California19 Perception and Frame Rate (Resolution: 512x384 pixels)

20. January 2006 MMCN, San Jose, California20 Perception and Frame Resolution (Frame Rate: 15 fps)

21. January 2006 MMCN, San Jose, California21 Outline Introduction(done) Methodology(next) Results(done) What’s Going On?(next) Conclusions

22. January 2006 MMCN, San Jose, California22 60 fps15 fps 7 fps3 fps Effects of Frame Rate on User Performance

23. January 2006 MMCN, San Jose, California23 Example – 15 Frames per Second

24. January 2006 MMCN, San Jose, California24 Example – 7 Frames per Second

25. January 2006 MMCN, San Jose, California25 Example – 3 Frames per Second

26. January 2006 MMCN, San Jose, California26 Effects of Frame Resolution on User Performance 640 x 480320 x 240

27. January 2006 MMCN, San Jose, California27 Example – Resolution 320x240 Frame rate: 30

28. January 2006 MMCN, San Jose, California28 Conclusions Frame Rate larger impact on performance than Frame Resolution –Frame Rate critical for adequate game performance Frame rates of 3 fps and 7 fps not playable 60 fps provides 7-fold increase over 3 fps –Frame Resolution has little effect on user performance Users as effective at 320×240 as at 640×480 Frame Rate and Frame Resolution both important for user perception –Effect of frame resolution similar to effect of frame rate –Top frame rate tested (60 fps) shows limit –Top resolution tested (640x480) not at limit Perceived quality increases linearly with square pixels Dramatically different previous research on video –Showed converse, that Frame Resolution mattered more –Suggests challenges in designing devices for games and video

29. January 2006 MMCN, San Jose, California29 Future Work Other aspects of First Person Shooters –Different map conditions –Movement Other display tradeoffs –“Quality” from graphics effects Anti-aliasing, realistic water/grass … Additional demographics studies –Gender, age, gaming experience … Other computer games –Real-Time Strategy, Sports …

30. The Effects of Frame Rate and Resolution on Users Playing First Person Shooter Games Mark Claypool CS Department Worcester Polytechnic Institute http://www.cs.wpi.edu/~claypool/papers/fr-rez/ Kajal Claypool Feissal Dama CS Department University of Massachusetts, Lowell