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Gameplay and Design Issues in Outdoor Augmented Reality Games. SPEAKERS: Assoc. Prof. Bruce Thomas Director of Wearable Computer Lab, UniSA Chief Technical Officer, a_rage pty ltd Dr. Wayne Piekarski, Assoc Director, WCL Director of Research, a_rage pty ltd Benjamin Avery
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Gameplay and Design Issues in Outdoor Augmented Reality Games
SPEAKERS: Assoc. Prof. Bruce Thomas Director of Wearable Computer Lab, UniSA Chief Technical Officer, a_rage pty ltd Dr. Wayne Piekarski, Assoc Director, WCL Director of Research, a_rage pty ltd Benjamin Avery UniSA Computer and Information Science Honours student, WCL Lead Game Programmer, a_rage pty ltd Joe Velikovsky Creative Director & Game Design Lead, a_rage pty ltd
OVERVIEW: 3 AR Game Case Studies ARQuake – Assoc Prof Bruce Thomas 3-D Moon Lander & the ARAGE Hardware – Ben Avery 3-D Sky Invaders – Joe Velikovsky
Gameplay & Design Issues in Outdoor Augmented Reality GamesCase Study:ARQuakeAssoc. Prof. Bruce Thomas, WCL UniSA
What do people like & dislike about ARQuake? • What aspects of the game should be highlighted? • What should be avoided?
ARQuake in a nutshell: • Built in 2000, first `Outdoor AR GPS’ game • Take a desktop pc First-Person-Shooter game and modify it - to be used as an indoor/outdoor AR game. • Track the user’s head orientation and position in an indoor/outdoor setting. • Player, NPCs (Critters, Monsters), & Game Objects (Health, Guns, Armour, Ammo) are all rendered normally. • Model physical buildings - and render the game walls black, co-located with physical walls.
ARQuake in a nutshell: • Black will appear transparent in HMD to the user, but the rendered black graphics will occlude monsters, critters and game objects. • Virtual walls, corridors, pillars, and doors are all still rendered. • As the user walks around the physical world moving their head, the game will update with this orientation and position information.
demon New textures Old textures
ARQuakeIn-Game Footage: Video 1
Field of View (FOV) • FOV of the HMD was 24 degrees horizontal • Necessitated excessive head-turning by the users. • thought to be “extremely narrow”. • FOV of 90 degrees • commented that this felt much better. • Registration problems. • FOV of 120 degrees. • “weird”; difference in parallax: physical virtual - uncomfortable.
Visuals That Worked Well • Floating objects worked well: • “they looked like they belonged in the game world.” • Users simply accepted them as part of the game. • One effect the users liked was flames: • “the fire in ARQuake looked pretty good” and “it looked genuinely like fire.”
Walking Around • Users were able to walk through the virtual walls. • “Walking through walls, while being an interesting idea….. It looked solid, but I wasn't worried about walking through it because I knew that there was a room on the other side. Strangely enough, I didn't want to go out the other side….” • One user noticed at one point, they were physically walking up a hill, but the game depicted flat ground. They stated it seemed to feel, while unexpected, easier to walk up because it looked flat.
Interaction • Users experienced difficulties picking objects up. • Objects “tantalizingly” within arm’s reach, but could not be picked up. • This problem became quite frustrating for some of the users. • Opening and closing doors - not difficult • Flying monsters require the correct weapon and strategy
Conclusion: • Users overall, enjoyed ARQuake • Issues with Field Of View. • Small orientation errors - quite noticeable. • The standard shape of doors & corridors in Quake worlds - not well-suited to ARQuake. • The world feels better to the user, if it is brightly-lit. • Use of skybox/sky colour should be avoided. • Users did not like the use of shadows. • Floating objects work quite well in ARQuake.
A Study of Performance of Consumer Level HardwareforOutdoor Augmented Reality Gaming by Benjamin Avery Supervisor: Assoc Prof Bruce Thomas Assoc. Supervisor: Dr Wayne Piekarski
This Presentation: • Background • AR On-The-Cheap • Game Technology • Example AR Game: 3D Moon Lander • Conclusion
a-rage • Research for a-rage AR game dev company • a_rage & ITEK provided scholarship for studies
Background: • Augmented Reality is: the overlay of computer-generated images onto the real world, using a Head Mounted Display
Other Indoor AR Games Examples of Indoor AR games: • AquaGauntlet • AR2Hockey • MIND-WARPING • TouchSpace • etc
Indoor is Easy: • Trackers can be tethered • Very accurate trackers available • Controlled environment Image courtesy polhemus.com
Outdoor is Harder: • Unpredictable environments • Lower-accuracy trackers • Limited computer power • Limited power • Mobility and reliability • OST vs VST HMDs
Outdoor AR Games Only two real examples: • ARQuake • Human Pacman
…I want one at home? • Expensive systems exist • Accurate tracking(50cm), high-resolution, compact • Cost: AU$20,000 • Too expensive for kids to play games on! • Need a consumer- level alternative
The Question: Can AR games be designed and implemented, in such a way as to make them playable on low-performance level hardware?
AR `On-The-Cheap’ Our consumer-level hardware system: Possible cost: ~$500
What problems does this cause? • Cheap GPS is only accurate to 5 meters • Trackers ‘drift’ • PAL/NTSC resolution • Limited input so: • in your backyard is not yet possible…
Game Design vs AR Technology! • Make the game fit the hardware limitations • eg. OST - ‘ghosts’ in Ghosts of Sweet Auburn • GPS ‘snap-to’ grid system, with hysteresis • Picking the correct tracker • Avoid registration with the real world
3-D Moon Lander • Example AR game - demonstrating the concepts • Based on 1979 Atari game Lunar Lander - and pc clones
GPS Snap-To: Video
Conclusion • Many games can be designed to work on this hardware platform • Problems do exist, but careful Game Design can work around these • We have tested the system outdoors and the GPS snapping and tracker work well • Further play-testing by a_rage will reveal any other problems this system may offer, which we can then improve on.
AR Game Design • joe velikovsky [Game Design Lead]game designer former national games market analyst, InformBACS, AFTRS JOETEEVEE.COM10 years in the games industry
Design Elements • 3-D AR `port’ of Space Invaders • 5 m GPS = • 2 locations 5m apart • (Turret & Bunker) • Immersive game space = N,W,E, • Flames & floating objects = UFO FPS! Set in 1950’s • UI = intuitive = HMV is pointing device as per ARQuake • Content = TV set! • Directional sound • Dev cycle = short
5m GPS TURRET 5m BUNKER
"I hope that peripheral companies start to look at opportunities for getting the joystick out of peoples’ hands and doing something different, - or getting us away from the TV screen with something like Head-Mounted Displays. I would love to see someone take on this challenge of establishing a real virtual environment with the power that the new consoles should provide." Ted Price, CEO, Insomniac Games Spyro, Ratchet & Clank from IDG 2003 Games Industry White Paper p. 94-95 IDG 2003 GAMES INDUSTRY WHITE PAPER
DESIGN PHILOSOPHY 1) Port `hit’ games over to AR [Space Invaders: Old Games, New Platform] 2) K.I.S. - Keep It Simple! [Games low on Graphics / high on Gameplay] 3) Play-Balance/Flow Theory - `Challenge & Reward’ 4) 10 Mini-games (like EyeToy bundle) 5) Risk management - Shorter Dev Cycle! Later: bigger budgets, and longer games
GAME DESIGN 1) USER-FOCUSED GAMES (`Plug & Play’) 2) SIMPLE ADDICTIVE GAMEPLAY = FUN FACTOR 3) HIGH REPLAY VALUE 4) Age: 15+ - for physical co-ordination 5) SAFETY - in goggle view is never `off’
