4.5 A VIRTUAL REALITY LEARNING ENVIRONMENT

Noah Nigg*, Mohan Ramamurthy, Robert Wilhelmson, Joel Plutchak,David Wojtowicz, Daniel Bramer

University of Illinois at Urbana-Champaign, Department of Atmospheric Sciences

1. Introduction

Three-dimensional models allow students tostep away from the two-dimensionalcharacter of conventional diagrams, andstart visualizing scientific phenomena asthey might appear in the “real world.”Furthermore, if the three-dimensional modelcould be made interactive, students couldexplore the model from any perspective in 3-d space, creating the basis for a VirtualReality Learning Environment. The scientificresearch community already has 3-dvisualization tools at their disposal, such asCAVE1, ImmersaDesk2, or Vis5d3, but thesetools would not be deployed in a classroomsetting due to their high cost, and highcomplexity. In addition, these complex toolscannot be operated from the Internet.

With rapid improvements in desktopcomputers, and the increased use of theInternet, new inexpensive multimediatechnologies for three-dimensionalvisualization have been developed. Onesuch technology is Virtual Reality ModelingLanguage (VRML). VRML runs on adesktop computer, and can be operatedfrom the Internet. We have utilized VRML tomake a Virtual Reality Learning Tool (VRLT)for scientific data. This tool could be used ina constructivist setting, where studentscould learn the material through “hands-on”exploration rather than just passivelyviewing slides or videos.

2. What is VRML?

VRML is a scripting language developed by

__________________________________*Corresponding Author Address:Noah Nigg, Dept. of Atmospheric SciencesUniversity of Illinois at Urbana-Champaign105 S. Gregory St, Urbana, IL 61801E-mail: nnigg@atmos.uiuc.edu

1,2 http://www.ncsa.uiuc.edu/Vis/Facilities/3http://hpux.cict.fr/hppd/hpux/Maths/Misc/vis5d-4.3/

Silicon Graphics, Inc. which allows aprogrammer to render three-dimensionalscenes in a Web browser. A scene includesthe model and the three-dimensional spacewhere the model resides. With the use of afreeware browser plug-in, such as CosmoPlayer4 , a VRML scene can be viewed viathe Internet, CD-ROM, hard disk, or floppydisk. When a user accesses a VRML filethrough a Web browser, the plug-inautomatically launches, giving the userinteractive control over the three-dimensional VRML scene through the use ofa mouse or keyboard commands. Thescenes load and render quickly, even thosethat are downloaded from the Internet, andthe interactive controls are simple tooperate. With these controls, the user canmove the model on any axis, allowing themodel to be viewed from all angles, or “fly

through” the model as if he or she were “in”the model itself. Although the renderingquality of VRML may be somewhat less thanthat of the expensive software packages, formost desktop computers, VRML canproduce high-quality renderings ofphenomena such as thunderstorms andhurricanes, showing cloud structure, verticalor horizontal cross sections, wind flow,temperature, rainwater, pressure, or any

__________________________________4 http://cosmosoftware.com

Figure 1: An example of the VRLT displayinga “virtual tour” of Hurricane Opal.

other applicable variable. VRML allows for3-d model visualizations to be readilyaccessed in homes and schools from just adesktop computer with a Web browser.

The latest specification of VRML is VRML97(ISO/IEC 14772), which we used in ourVirtual Reality Learning Tool. VRML97contains many interactive features such asanimation, touch sensing and proximitysensing. Virtually any parameter within aVRML97 scene can be altered by the userby including separate functions within theVRML script to recognize when a user hasinteracted with the scene.

3. Why Virtual Reality?

With the interactive capabilities of VRML,the student becomes an active participant inthe material he or she is viewing.Multimedia presentations in the classroomare nothing new— but until now, thesepresentations consisted of videos,transparencies and slide shows— all passivelearning tools, where the student wouldsimply watch what is presented, and askquestions later. In the Virtual RealityLearning Environment, the student cannavigate through a “virtual world,” as if he orshe were flying, walking, or hovering throughthe scene. A student can see the scenefrom all angles and distances, and canchoose a destination or trajectory at will.Using a three-dimensional movable scene,the question “what is behind the diagram?”will no longer need to be asked. Studentsare likely to be more intrigued by the subjectof the scene if they can interact and “travel”through the scene. This is a clear advantageto students who learn better with the “hands-on” learning style.

The user can also “peel away” areas of themodel to see obscured areas using theinteractive controls within the scene. Thisautomatically takes the place of severalimmovable diagrams, which only displayvisualization from one perspective. It is theunlimited control over perspective, whichcan allow a thoroughly three-dimensionalvirtual reality view of a scientificphenomenon. This paves the way for astand-alone virtual realty tool which containsthe scene, interactive controls, and textualexplanations of the scene. This would allow

the student to visualize a scientificphenomena (in the form of a numericalmodel simulation) at his or her own pace.

The real value in using VRML and virtualreality for learning is not simply the fact thata student may liken the VRML controls to avideo game. Otherwise, the Virtual RealityLearning Tool may be considered merely atoy. The value comes in when the VRMLscene is linked to activities relating to thatscene.

The instructor may give out assignmentsasking students to identify key featureswithin a VRML scene, and through a seriesof questions or activities, ask students torelate what they have explored to the lectureor textbook material. Interactive controlsmay be provided within the VRML scene toguide the student to key features through aparticular trajectory. Also, destinations to allthe major features may be pre-programmedwithin the controls so students can seethese features close-up, far away, above,below, or from any angle. The student couldthen do their own exploration of that featurein order to answer the questions provided.

4. The Audience

The Virtual Reality Learning Environmentmay be beneficial to all grade levels--gradeschool through graduate school. Thevariable would certainly be the difficulty anddetail of the activities relating to the virtualreality VRML scene.

In addition, scientists may find the virtualreality environment of VRML to be a quick,and effective way to visualize numericalmodel data on the desktop, or over theInternet.

5. The Virtual Reality Learning Tool

Using VRML97, we have developed aVirtual Reality Learning Tool (VRLT)prototype in order to visualize scientific dataover the Internet or from disk, on desktopcomputers. The prototype makes use of anumerical model simulation of HurricaneOpal. The data comes from the MM-5 model

at 5km resolution, inner grid5. For details ofthe MM5 simulation of Hurricane Opal, seeRamamurthy & Jewett (1999). The data wasfed into vtk6 Software programs andconverted to VRML2.0 (VRML2.0 was theprevious version to VRML97). The VRML2.0files in ASCII format were edited to includethe interactive controls such as the “tour”feature. Many of the edits to the files usedthe VRML97 Standard, and thus the VRMLfiles became VRML97 files. These files werereduced in size by compression (gz) andother methods. The files were thendisplayed using the freeware Cosmo Player1

plug-in and the Netscape 4.0 browser on anIBM PC Compatible running Windows 95 orNT.

Figure 1 shows an example of the VRLTprototype in action. The variable displayedis rainwater with an isosurface value of0.01g/kg. The time of the simulation is 84hours, just before the hurricane madelandfall. The VRML scenes are produced bysurface rendering, which means that eachisosurface is hollow, and additionalisosurfaces would have to be included in thescene to produce more of a volumerendering, or more “real” interpretation of theobject in the scene. This can beaccomplished, but the more isosurfaces thatare added, the larger the VRML file, and theslower the download and render time.Therefore, the VRLT prototype uses thefewest isosurfaces possible to convey thegeneral structure of the features beingrendered. Figure 1 also displays the “tour”feature, where clicking on one of the “tour”buttons in the navigation menubar on theright of the window will take the user on avirtual tour of the Opal simulation. A pop-upbox describes the tour trajectory. Also,other controls may be included in thenavigation menubar to display crosssections or other variables (Figure 1 has“box on”, “box off” controls). The navigationmenubar can be minimized to broaden thefield of view. In addition, the VRLT prototypehas pre-programmed destinations within theCosmo Player controls. The mouse cancontrol the Cosmo Player controls for further_______________________________________________________________

5 provided by Crystal Shaw, Brian Jewett, NCSA,Urbana, IL 618016 http://www.kitware.com

navigation using the self-described buttonsbelow the scene. The file size of thisparticular scene in Figure 1 is 390 kilobytes.

6. Adaptability

At the time of this article, the VRLTprototype ran best using Cosmo Player inNetscape 4.0 in a Windows environment.There is currently a version of Cosmo Playerdesigned for Macintosh, but it has not yetbeen thoroughly tested with the VRLTprototype.

7. Future Work

Advanced Multimedia Educational Websites:These would be a new generation ofscientific educational modules which wouldinclude VRML, streaming video andanimations. Key frames of the streamingvideo of an actual weather phenomenon,such as a hurricane, would be hyperlinked toVRML simulations (using the VRLT) of thephenomenon for a virtual reality study.Textual information would supplement theVRML and streaming video content. TheVRML scene itself could contain hyperlinksto pages describing the content of the scenein more detail using text and diagrams.

Additional interactive controls utilizing Javaor JavaScript could be added to retrievenumerical data from the VRML scene as it isbeing explored. This would allow a studentto see, for instance, how the temeperaturechanges through a hurricane as if thestudent were “holding a thermometer” while“flying” through the scene.

Use in the Classroom: The virtual realitylearning environment would be introducedinto Atmospheric Science survey courses atthe University of Illinois to supplement thetraditional multimedia presentations. Theeffectiveness of the virtual reality tools couldbe observed first-hand, and improvementsor additions to the tools could beimplemented.

Activities could be designed to explore thestructure of an atmospheric phenomenonsuch as a hurricane. Students could beasked to comment on the eyewall structure,spiral rainbands, airflow, and thermalstructure, and then relate what they see in

the VRLT to what is presented in lecture.The real difference between 2-d and 3-dwould clearly become evident.

8. Additional Information

Additional information on VRML97 can befound at the Website:

http://vrml.miningco.com

The vtk Software Website:

http://www.kitware.com

9. Acknowledgements

Others who helped with the development ofthe VRLT prototype: Paul Rajlich and JohnShalf (NCSA) for their help with the vtk hdfreader, and Crystal Shaw and Brian Jewett(NCSA) for preparing the MM-5 hdf data.

References:

Bramer, et al., 1999: Integrating Real-TimeWeather Into An Internet LearningEnvironment: WW2010 Current WeatherProducts. Proceedings of the 8th

Symposium on Education. Dallas, Texas,American Meteorological Society.

Plutchak, et al., 1999: Advanced Multimediafor Education on the Internet. Proceedingsof the 15th IIPS Symposium. Dallas, Texas,American Meteorological Society.

Ramamurthy, M.K. & B.F. Jewett; 1999:Ensemble Prediction of Hurricane Opal’sTrack and Intensity. Preprints, 23rd

Conference on Hurricanes and TropicalMeteorology. Dallas, Texas, AmericanMeteorological Society.