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1. INTRODUCTIONVisualisation is becoming a more andm o re important component of anyengineering or science-related pro j e c t .Advanced visualisation tools allow thesimulation and viewing of increasinglycomplex models which in turn allowresearchers and scientists to manipulatethem in ways never imagined before.

Virtual Reality (VR) is a visualisationmedium composed of interactivecomputer simulations that combine 3-Dcomputer graphics and diverse technicalsystems that provide a large field of viewand a stereo effect to the user, resulting ina feeling of being immersed or beingp resent in the simulation. Using theVirtual Reality Modeling Language(VRML), the entire 3-D virtual world willbe created where one can “walk” through(or around) the objects and manipulatethem. The term “Virtual Reality” wasinitially coined by Jaron Lanier of VPLResearch [1]. Other related terms include“Artificial Reality” [2], “Cyberspace” [3],and, more recently, “Virtual Worlds” and“Virtual Environments” [4].

The purpose of this paper is to sharethe knowledge and experience in settingup a Virtual Reality laboratory atUniversiti Industri Selangor (UNISEL)City Campus in Shah Alam, Selangor. Anoverview of VR applications is firstgiven, followed by a description of theVirtual Reality lab at UNISEL and ourexperience in setting up the lab until itsfull operations.

2. VIRTUAL REALITYAPPLICATIONSVirtual reality is used in many differentapplications, ranging from architectureand engineering to bio-informatics,medical science and entertainment.

P e rhaps the most obvious applicationsof VR are in the fields of arc h i t e c t u re ,engineering and manufacturing, asillustrated in Figure 1. Virtual Realityhelps to improve quality of designincluding its ergonomics by allowingmany diff e rent design alternatives to besimulated, evaluated and selected in a

very short time. It also offers the user a“ w a l k - t h rough” view of the simulation sothat problems can be found and designi m p rovements can be made earlier andf a s t e r. “Virtual Prototyping” as this iscalled, significantly aids in testing andperfecting products (automobiles, airc r a f t ,buildings, etc.) before actual constru c t i o n .By simulating motions too, VR has foundvery useful application in the study ofdynamic effects and fluid flow.

The medical field is anotherpromising field of application for VR.Many medical applications useaugmented virtual reality systems thathelp doctors in, for example, studyingblood circulation inside the body, orvisualising certain parts or organs of thebody in virtual re a l i t y. In thepharmaceutical and biotechnology

industries, scientists use Virtual Realityto visualise and manipulate complexD N A molecules in formulating new drugs.

VR technology has also beenextensively used in education andtraining in all the fields described above.With VR, students can learn moreeffectively as the 3-D representation and“walk-through” view of the simulationcan ease visualisation and understandingof complex objects and stru c t u re s .Besides, they can also have a hands-onexperience in manipulating the objectssuch as by removing or swapping theircomponents.

3. THE VR-LAB AT UNISEL’SRESEARCH ANDCONSULTANCY UNIT (UPPU)3.1. Choice of Set Up and OverallSystem IntegrationThere are two types of screens in a VR setup: a flat screen or a curved screen. Flats c reens can be in a single wallconfiguration (i.e. single pro j e c t i o nchannel), or in a “powerwall’configuration (ie. more than onep rojection channel but still only onescreen in front of the user). Flat screenscan also be in a “cube” configuration (e.g.CAVE TM ) with screens also on the leftand right of the user. Flat screens providehigher accuracies and are used in mostengineering and architectural set ups.The curved screen is more useful forsimulation works (e.g. pilot simulations)and for entertainment (e.g. 3-D games,cartoon productions) since with such aset up, the user feels more immersed inthe environment.

Appropriate for its intended use,U N I S E L’s VR Lab employs a 2-channelP o w e r Wall set up. The overall network andsystem integration more is shown in Figure2. The PowerWall set up is powered byLinux-based clusters running ICIDO (“Isee I do”) virtual reality software. Theimage, created from various modeling andCAD/CAM/CAE applications, isp rojected on a large flexible flat scre e n .Together with its hard w a re and software ,

The Setting Up of a Vir tual Reality Lab: The Unisel Experience ......................................................................................................................................................................................................................................................................

By: Cik Rahayu binti Abdul Rashid, Engr. Yusliza binti Yussof and Engr. Assoc. Prof. Dr Arazi bin Idrus, M.I.E.M., P.Eng.

Figure 1a, b, c: Example VR Applications in Engineering

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the UNISEL set up is said to be the mosttechnically advanced in the country.Similar set ups have also been used bymany large automotive companies such asB M W, Volkswagen and Daimler- C h r y s l e rin Germany.

3.2. H a r d w a reH a rd w a re for the UNISEL VR labbasically consists of 4 Linux-basedclusters, 4 sets of Christie “Vivid Blue”p rojectors (including filters), a Cyvix“xed.1” blending pro c e s s o r, a Stewart“Silver wall” screen, Ascension “Flockof Birds” motion tracking system, a setof input device and polarised 3-Dg l a s s e s .

The 4-node Linux clusters (Figure3a) drives each of the 4 projectors andalso powers the 2-channel PowerWa l l .All four Linux nodes in the cluster mustrun concurrently to produce two imagesat each channel. The Master Linux nodealso houses the graphic system and ru n sthe IDO virtual reality software as wellas various modeling and CAD/CAM/CAE applications. As for thegraphic system in the clusters,“ Q u a d roFx” was chosen in view of itssuperior performance and cheaperinitial and maintenance cost compare dto its competitors.

The projection system (Figure 3b) isone of the most important components

of a VR set up. Each of the 2 channels inthe PowerWall set up re q u i res 2separate projectors to produce passive3-D stereo images to the user (one forthe left and one for the right eye). Thus,for a 2-channel set up, a total of 4p rojectors were needed. The “Vi v i dBlue” high quality multimediap rojectors have full SXGA resolution of1280x1024, capable of giving very sharpand clear images.

The Cyviz xed.1 Soft Edge blendingp ro c e s s o r, (Figure 3c) is located betweenthe clusters and projectors. It pro c e s s e sdisplay signals from the clusters andintegrates the whole VR system.

The projection screen, 6m wide and2.6m high, is a custom-designed flexiblerear projection screen made by StewartF i l m s c reen Corporation. This scre e nuses Techplex150 materials, which has adark tint for additional contrast and isexcellent in rooms with wide viewingangles and where high ambient light is aconcern. This screen is fixed in aretractable frame.

Interface between the user and theVR software module is provided by theinput device in the form of a joy stickand a head tracker. The device contro l sand perform manipulations within theimmersive environment and is linkedto the Ascension “Flock of Bird s ”tracking system.

The Ascension Flock of Birds (Figure3d) is a 6 degre e s - o f - f reedom trackingsystem which can track the position andorientation of the user withoutrestrictions, delay or lag. There is also noneed for a clear line-of-sight betweensensors and transmitter as blocking isnever an issue.

The polarised 3D glasses enable thedisplay of passive stereo generated bythe Linux clusters for the left and righte y e s .

Figure 2: Overall network and system integration diagram

Figure 3: Among the hardwae installed (a) Linux-basedcluster (b) Vivid Blue Projectors (c) Cyvix blendingprocessors (d) Flock of Birds tracking system

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3.3. SoftwareThe three basic VR software which arec u r rently installed in the system are“IDO:Review”, “IDO:Connect Standard”and “IDO:Cooperate”. The IDO:Review allows the user toimport 3D objects from compatiblesoftware and view or manipulate themwithin the VR environment. Among thefiles that are readily supported by thiss o f t w a re include .wrl (VRML), .iv(Inventor), .obj (Wavefront Object), .stf(Stereolithography) and .model files. TheIDO: Connect Standard is a 3D dataadapter which directly converts other 3-D data files into VRML and connectsthem to the IDO:Review. Among thepopular CAD/CAM/CAE and modelingapplication that can be converted areC ATIA, NASRAN, AutoCAD 3D,MIKE21, ProENGINEER, IDEAS FEAand NASRAN FEA. The IDO:Cooperates o f t w a re allows diff e rent teams ofengineers and scientists with similar VRh a rd w a re / s o f t w a re set up but indifferent locations to work together onthe same project .

4. PROJECT IMPLEMENTATION4.1. Planning and SchedulingRealising the potential and benefits of VRt e c h n o l o g y, UNISEL, through its Researc hand Consultancy Unit (UPPU) embarkedon a project to set up a VR laboratory in

January 2004. Contract for the setting up ofthe lab was given to a local company, OpenS o u rce Systems Sdn Bhd (OSS), withexpertise and equipment pro c u red fro mICIDO GmbH of Stuttgart, Germany.

Based on a previously accepted designp roposal, the scope of the contractincluded detailed design, supply,installation, tuning, optimisation, testingand commissioning of the entire VR

Figure 4: Project implementation programme

Figure 5: Actual floor layout of UNISEL VR Lab (Not to scale)

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h a rd w a re, software and the system. Thepackage also included a 12-monthmaintenance service for the lab. Thecomplete implementation programme forthe project is as shown in Figure 4.

Although the official contract periodgiven was 9 months, the contractor wasable to physically complete the projectahead of schedule. However, due to someadministrative problems, the lab wasonly operational in January 2005.

4.2. Room physical requirementsThe physical re q u i rement for the VRlaboratory room plays an importantpart as minor defects can affect the performance of the virtuale n v i ronment.

4.2.1. Room layoutI d e a l l y, the room should have an “openplan” design with no columns withinthe floor area to avoid obstruction toboth image projection and sight. In theU N I S E L p roject, the laboratory wasbuilt from a converted lecture room onthe ground floor where all thenecessary renovation work was carriedout and completed prior to the actualsetting up of the lab. The actual floorlayout of the lab is shown in Fig. 6 andconsists of a projector and an audiences e c t i o n .

4.2.2. DimensionsThe minimum size of the laboratoryroom depends on the maximum size ofimage intended to be projected on thes c reen as this will dictate the size of thes c reen and exact positions or “stand-o ffs” of the projectors. For the UNISELp roject, it was specified that the scre e nmust be large enough so that a re a l - s i z eimage of the Proton Perdana would fitin. The minimum size of the lab willalso depend on whether projectors arein front or at the back of the screen (see4.2.3). With projectors at the back of thes c reen and with floor dimension of7.3m x 18.3m and ceiling height of3.7m, the size of the UNISEL VR lab inFig. 5 is about the minimum re q u i re dto meet the specification. However, foroptimum projection and users’interaction, a bigger space would bed e s i r a b l e .

4.2.3. Using front or rear pro j e c t i o nFlat screen set ups can have projectorslocated at the back of the screen (rearprojection) or in front (front projection).Rear projection is the one preferred andchosen for the UNISEL lab because therewill not be any equipment blocking theaudience’s view since all of them will beplaced at the back of the scre e n .H o w e v e r, rear projection has adisadvantage as more laboratory space isneeded to house a separate projector andan audience section. In a front projection,all the projectors and equipment areplaced in the same section as theaudience. Although this could meansavings in lab space, problems might notonly be blockage to audience view butalso blockage to image projection by theuser him/herself.

4.2.4. Room interiorThe projector section of the ro o mshould be dark, thus internal walls arealso painted black. Black surfaceabsorbs all the visible lights hitting thesurface so that none will be re f l e c t e d .This will enhance the 3-D effect of thevirtual environment. Besides, allwindows should also be covered withcurtains to keep ambient light fro mentering the room.

4.2.5. Room temperature andhumidityThe laboratory room must be air-conditioned at all times, particularly inthe projector section. The airconditioning system should bemaintained at a temperature of around23°C. The humidity of the room mustalso be kept low.

4.2.6. Power supplyThe electricity supply can be normalsingle–phase electricity but must bestable. Lightning arresters should beinstalled in the building to protect theexpensive equipment from lightning.

4.3. Problems and difficultiesencounteredA number of problems or difficulties weree n c o u n t e red during project implementationbut most were considered minor and didnot seriously hinder work pro g ress. Thesea re as follows.

4.3.1. Finding suitable room for theVR LabIt was difficult to find a suitable ro o mfor the VR lab since the fro n t - p ro j e c t i o nsetup is unique while the re q u i re ds c reen size (6m wide and 2.6m high) isc o n s i d e red large. The room must also beable to accommodate the projectors andat the same time be spacious enough tofit in a typical classroom-size audienceof about 30 persons. Allowing for thes t ructural framing around the fourperimeters of the screen, this means theroom must have at least a width of 6.6m,a clear ceiling height (with no cro s s -beams pro t ruding below the ceiling) of3.2m and a length of 20m. A room ofsuch dimension and layout was notavailable at the City Campus at thattime. The nearest to this was of thatshown in Figure 5 but with two existingand non-removable features inside it,the fire-fighting water tank room (T)and the staircase stru c t u re (S). Thes t a i rcase only affected audience capacityand so was not a big problem. Thewatertank room, however, did affect thepositioning ad stand-offs of the 4p rojectors as its walls obstructed the“line of sight” of the projectors. Too v e rcome this, the projectors had to beplaced nearer to the screen, resulting ina slightly smaller projected image.Despite this reduced image and perh a p s“ u n d e r-utilisation” of the screen size,fortunately with some adjustments, areal-size image of the Proton Perd a n awas still obtainable with the lab.

4.3.2. Image GhostingC i rcular filters, installed immediately inf ront of the projectors, would allow 3-Dimage to be perceived even when theu s e r’s head is tilted. However, the natureof these filters also allows some “imageghosting” (shadows on bright-coloure dand high-contrast images) to appear whichcan badly affect the 3-D effects. To avoidthis, the circular filters were replaced withlinear ones to achieve greater imagesharpness and accuracy.

4.3.3. Filter standThe original filter stands were built-in(fixed) in front of the projectors, and did notallow fixing of the linear filters in place ofthe circular filters without also re m o v i n g

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the stand. To overcome this, a re t r a c t a b l estand was built that will allow only thefilters to be replaced whenever necessary.

4.3.4. Network connectionDuring testing and commissioning of thelab, the internet service from theuniversity’s wireless network wasf requently interrupted and slowed downthe process of downloading the IDOs o f t w a re and testing of the IDO:Cooperate.F o r t u n a t e l y, this problem occurred only fora short period and with the help of wire dconnection, testing and commissioningw e re able to be done successfully.

5. CONCLUSIONVirtual Reality is an emerg i n gvisualisation technology that allowsdesign engineers and scientists to viewand interact with their simulatedmodels as if being really present in thesimulation. There are a number ofconsiderations to take into accountwhen setting up a Virtual Reality (VR)l a b o r a t o r y. The first is to know thepurpose the lab is built for. If it is forp rototype testing and designing

(engineering or scientific applications),then the flat screen set up (such asU N I S E L’s 2-channel PowerWall) is mostsuitable. But if it is only for simulationworks, then the curved screen set upwould be more appropriate. Equallyimportant is the specific room physicalre q u i rements that need to be met withre g a rd to for example, room layout anddimensions, projection type (front orrear), room interior and ro o mt e m p e r a t u re and humidity.

Considering that VR is still new inMalaysia, we are faced with challengesassociated with a small community inR e s e a rch and Development in the field andindustry awareness. UNISEL, being one ofthe first institutions of higher learning in thecountry to have set up a Virtual Reality lab,welcomes interested parties both from thepublic and the private sector to worktogether with UNISEL in developing andharnessing the potential of this technologyt o w a rds mutual benefits. ■

R E F E R E N C E S

[ 1 ] Bernatchez, M. “VRApplications”. Virtual RealityR e s o u rces. December 21st,2 0 0 4 ,h t t p : / / v re s o u rc e s . o rg / a p p l i c a t i o n s /applications.shtml

[ 2 ] F e i n e r, S. “User Interfaces,Interactive Graphics, Vi r t u a land Augmented Reality”.Computer Graphics & UserInterfaces Laboratory,University of Colombia.h t t p : / / w w w 1 . c s . c o l u m b i a . e d u / g r a p h i c s

[ 3 ] Stewart, P. and Buttolo, P.“Putting People Power IntoVirtual Reality”. Pre m i e reissue, Mechanical EngineeringDesign, November 1999.h t t p : / / w w w. m e m a g a z i n e . o rg /supparch/medesign/index.html

[ 4 ] B e i e r, P. “Virtual Reality: AShort Introduction”. Vi r t u a lReality Laboratory, College ofEngineering, University ofMichigan. February 10, 2004.h t t p : / / w w w - v r l . u m i c h . e d u / i n t ro /i n d e x . h t m l