a Virtual Environment
PasiVälkkynen,JuhaniHeinilä,SariLainio,SamiLakaniemi, andAntti
Väätänen
VTTInformationTechnology
Sinitaival6
P.O.Box1206
FIN-33101Tampere
Finland
Pasi.Valkkynen@vtt.fi,
WWWhomepage:http://www.vtt.fi/tte
Abstract. Virku(VirtualFitnessCentre)isastudy,inwhichanexer-
cisecycleisusedfornavigatinginavirtualenvironment.Thecycleacts
as ahapticbodilyuserinterface between the userand the simulation.
Thesimulationtakestheterrainofthevirtualenvironmentintoaccount
inordertoprovidebetterfeedbackoftheenvironmentfortheuser.We
havefoundoutinusabilityteststhatthiskindofinterfaceenhancesthe
user'sfeelingofimmersioninthevirtualenvironment.
1 Introduction
Virku(VirtualFitnessCentre, seeFigure1)isaresearchanddevelopmentpro-
gram in which aprototypeofatnessgameplayedwithanexercisecycle ina
virtualenvironmenthasbeenproduced[10].VirkuincludesalsoaFitnessMoni-
toringProgram fortestingtheuser'stnessleveland forsupporting longterm
tnessmonitoringandtraining.
Thepurpose of ourresearch is to study bodily user interfacesand the use
of a computer game to enhance motivation to keep t. In this paper, we will
concentrateonthebodilyuserinterfaceandespeciallyonhowtouseanexercise
cycleasahapticinputdevice inavirtualenvironment.
2 Background
2.1 Bodilyuser interface
With the bodily user interface we mean an interface, which allows the user
to interact with the interface using other methods than the traditional input
devices, such as a mouse or a keyboard. The user can also react with other
sensesalongwithhis visualorauralperception.
Bodily user interface is not a very dened term and there are sometimes
tnesscomputergameisagoodexampleforillustratingthesediculties.Wedo
notusuallyconsiderabicycleracingsimulationplayedwithmousetobeusinga
bodilyuserinterface.Wecould,however,replacethemousewithahandle-bar.
Does thismakethe interfaceabodily one?What ifwemake theusersit ona
bicycle seat and give him pedals for controllingthe speed of the cycle in the
game?
Inourresearch, wehaveused (somewhatvaguely)theterm bodily userin-
terfaceforaninterfaceinwhichtheuseruseshiswholebodyforcontrollingthe
system.InVirku,theusermovesthepedalswithhis legmusclesandsteersthe
bicycle with his hands. Wholebody weightcanbe used forexamplefor riding
uphillin ordertogainmorepowerforthepedaling.
Bodily userinterfacesare clearlyusefulfortnesspurposessincetheyforce
theusertomove,insteadofonlysittinginfrontofthecomputer.Wealsoshowin
thispaperthatahapticbodilyuserinterfacehelpstheuserfeelmoreimmersed
We usually get information from the computer systems by seeing and hear-
ing,andinputinformationbymanipulatingamouseand/orkeyboardwithour
hands.Thesemodesofcommunicationneglectourothersenses,touch,tasteand
smell. Of these three, smell and tasteare moredicult to include in human-
computerinteraction,butthisdoesnotnecessarilyhavetoapplytotouch.
AccordingtoTan[8],theterm"haptics"referstosensingandmanipulating
through the sense of touch. He divides haptic sensations into two categories:
senseoftouchandsenseofposture,bothofwhichareimportantinabodilyuser
interface.Thesenseofposturecanbeespeciallyeectiveinatnessapplication,
likeVirku,in whichwhole bodyisusedforcontrollingtheinterface.
Ina virtual environment, hapticsare an important partof theimmersion,
thefeelingof "beingthere".Inourterms,hapticsareapartofthebodily user
interface. Its purpose is to enhance the virtual environment's resemblance to
naturalenvironmentandthusmakethewhole experiencemorevivid,enjoyable
andcaptivating.
2.3 Other bicycle simulators
Usingabicycleasaninputdevicehasbeenstudied,forexample,withthePeloton
simulator[1],whichwasdevelopedasavirtualenvironmentforathletictraining
and competition. There arealso virtualrealitysystems,which use abicycle as
theirinputdevice,suchasJereyShaw'sLegibleCity[7]andtheDiamondPark
[11].LegibleCitycanbeconsideredasanartinstallationandDiamondParkas
astudyofsocialvirtualreality.
Otherbicycleinterfaceswithsimulatorsarecommerciallyavailableandtheir
purpose is usually to improve the users' tness. These include RealBitz.com,
WebRacing and CompuTrainer. RealBitz [6] uses a movement sensor, which
is attached to the user to sense the speed of his movements. WebRacing [12]
supports the use of VR helmet and it has a multiplayer game, which can be
played via theInternet. CompuTrainer[2] adds thepossibilityto design one's
owntrainingcourses.
Virkudiersfromthesesystemsbytakingtheterrainofthevirtualenviron-
ment into accountin itshaptic response and by allowing theuser to navigate
anywhereinitsvirtualworld.Intheuser'spointofview,thepurposeofVirku
istohelp himimprovehistness[5].
InVirku,itispossible,butnotrequired,fortheusers,tocompetewitheach
other or againstaclock.Instead, theycanalsoenjoythe gamejust by cycling
around the generated landscape and enjoying the nature and the views. This
is an importantdierence betweenthe commercial,more competition-oriented
gamesplayedwithexerciseequipment,and Virku.
3 Virtual Fitness Centre and Research Objects
InVirku,thebodilyuserinterfaceisanessentialpartoftheinteractionbetween
asynchronousRSinterfacetomovedatainandoutofthecycle.Itiscapableof
increasing its resistanceaccordingto commands sent from acomputer viathe
serialline,anditcantellthecomputeritsresistance,torqueandtheheartrate
of the user. We canuse this information for modifying the trainingsession so
thatthetrainingwillbeoptimal.Theusernavigatesinthevirtualworldentirely
with theexercisecycle.Thecycle hastwobuttons forsteering,and thetorque
ofthepedalsaectsthemovementspeed.
Thevisualpartofthevirtualenvironmentispresentedonacomputermon-
itor orit can be projected with a data projector onto a largescreen. We use
SimCore[3],acommercial3Dengine,torenderthescenery.Thescenerydepicts
aruralenvironmentfromthenorthern Finlandgenerated from digitalmapin-
formation.Virku usesamultichannelsoundsystem,whichcreatesanillusionof
threedimensionalsound.Theusergetsfeedbackfromthegamealsointheform
of resistance.Theresistanceis increasedwhen the userrideshis bicycle uphill
anddecreasedwhenriding downhill.
Virkuis designedto beusableinatnesscentre oragym.Typically, these
areenvironmentsin whichhead-mounteddisplayscannotbecomfortablyused,
becauseof sweat, humidity and heat. With the traditional tness devices, VR
equipmentisnotneeded,sotheuserswouldalsohavetoputthemonorremove
themeverytimetheywantedtousesomeothertrainingdeviceinthegym.This
iswhywedidnotwanttouseintrusiveequipment.Therefore,wecouldnotuse,
for example, stereo images of the landscape. So, the bodily user interface has
to enhancetheimmersionin ordertocompensateforthepossiblelossofvisual
realism.
The Virtual Fitness Centre also includes a tness monitoring program to
assisttheuserin longtermexercising.Itgathersinformationfrom theexercise
sessionsandusesittogivetrainingrecommendationsfortheuser.Thepurpose
ofthetnessmonitoringprogramistosupporttheoverallconceptofenhancing
theusers'motivationforadheringtoacertaintrainingprogramme,whereasthe
purposeofthegameistohelp theuserswithshorttermmotivation.
4 Evaluation and results
WeappliedtheHuman-CentredDesign(HCD)approachinthedevelopmentof
oursystem.TheHuman-CentredDesignisaniterativeapproachtodesignwhere
anactiveinvolvementoftheusersandaclearunderstandingoftheuserandthe
taskrequirementsareemphasised[4].
We tested the tness game with nine people, seven women and two men.
Theywereespeciallyfamiliarwithcomputergamesorvirtualenvironments.All
of them trainedat leastsomewhat actively(minimum onceaweek). Thetests
were conducted in the Usability Laboratory of VTT Information Technology.
Wearrangedanenvironment,whichconsistedoftheexercisecycle,acomputer
andalargescreenontowhichthescenerywasprojectedwith adataprojector.
datawasgatheredbyobservingtheusersandinterviewingthem.
Theusersfeltthattheywereexercisingratherthanplayingacomputergame.
Theylikedthegameandfeltthetitwasmoreentertainingthanusinganexercise
cyclewithoutagame.Theinterfacewasnaturalandintuitivetouse;theusers
knewimmediatelyhowto navigateinthevirtualenvironmentwiththeexercise
cycle.Theyalsotoldthattheyhadafeelingofimmersion.Attimes,someusers'
behaviour suggested that there was a feeling of riding a bicycle in a natural
environment. Some users, for example, were afraid to ride down a ridge (see
Figure 2), or they stood up on the exercise cycle to see better over obstacles
in theterrain. In theinterviews, they toldthat the immersion wasdue to the
combination of a large, impressive and realistic visual system and the bodily
userinterface.Theexperience ofthebodily interfacewasachievedby boththe
hapticresponseandusingthewholebodytocontrolthenavigation.
Fig.2.Aviewdownaridge
Oneproblemwiththehapticinterfaceisthat theresistancedoesnotadjust
accordingtootherterrainfeaturesthantheslope.Usefulbasesforadjustingthe
resistancewouldbeatleastsurfaceandvegetation.Thisisanimportantfeature
toimproveinacross-countrybicyclesimulation,anditwillbedealtwithinthe
fore, we can not expect to gain long term results until we have conducted a
prolonged eldtest study. Therstimpressionsof theusers,however,suggest,
thatthiskindofsystemmotivatestheminadheringtoatrainingprogram.The
reasonisthatatnesscomputergameaddsentertainmentvalueandnaturality
totheexercisesession comparedtotraditionalexercisecycling.
5 Conclusions
In conclusion, we found out that the bodily user interface was a tremendous
addition to thevirtual environmentand thegame. Userscan feelimmersed in
the environment without any intrusive VR equipment and stereo imagery. It
seemstous,that inthiskindofapplication, ahapticbodilyinterfaceisatleast
aseectiveasthetraditionalapproachwiththehead-mounteddisplays.
6 Future work
We will continue to develop the interface and the game during this year and
thenext;atthetimeofthiswritingweareabouthalfwaythroughourresearch
andhaveanotherfteenmonthsahead.Theimprovementswillinclude atleast
developingamultiplayergameinalocalareanetwork,inwhichmanyuserscan
train together in acommon session. The hapticresponse will be improved by
takingintoaccountotherterrainfeaturessuchasthesurfaceandvegetation.We
will also consider other extensions to the bodily user interfaceand implement
them if they seem appropriate. The Human-Centred Design approach will be
usedin thiswork;designsolutionswillbetestedwiththeusers.
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