Virtual Reality: Stereoscopic Imaging for Educational Institutions


Published on

Virtual reality (VR) in education is a markedly present subject in research institutions in many countries. This paper will discuss the application of VR techniques, including the use of computer graphics and three-dimensional (3D) video production. Stereoscopy is a key point for the visualization of these applications. The system developed uses a 3D lens, a home camera, common video edition software, two low cost projectors, light polarized filters and cheap 3D eyeglasses. During the 3D video production, the aim was to evaluate all the involved process, since the elaboration of scripts, video capture and projection until the costs to build the system. This is important to demonstrate for educational institutions the advantages in adopting resources of VR for the improvement of learning.
Artigo completo em:

Published in: Education, Technology
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Virtual Reality: Stereoscopic Imaging for Educational Institutions

  1. 1. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, BrazilVirtual Reality: Stereoscopic Imaging for Educational InstitutionsAntonio C. Amorim 1, Rodrigo D. Arnaut 2, Sérgio T. Kofuji 1, Anna H. R. Costa2 1 2 Laboratory of Integrated Systems (LSI) , Laboratory of Intelligent Techniques (LTI) University of Sao Paulo (USP) – Sao Paulo – SP – BrazilKey Words: Virtual reality, education, stereoscopy, 3D video, stereo visionAbstract Virtual reality (VR) in education is a markedly present subject in research institutions in many countries. This paper will discuss the application of VR techniques, including the use of computer graphics and three-dimensional (3D) video production. Stereoscopy is a key point for the visualization of these applications. The system developed uses a 3D lens, a home camera, common video edition software, two low cost projectors, light polarized filters and cheap 3D eyeglasses. During the 3D video production, the aim was to evaluate all the involved process, since the elaboration of scripts, video capture and projection until the costs to build the system. This is important to demonstrate for educational institutions the advantages in adopting resources of VR for the improvement of learning.1 IntroductionThe two largest obstacles for adopting resources of Virtual Reality (VR) in educationalinstitutions are the high costs of equipment and the cultural barrier. The cultural barrier is anobstacle because it is essential to have specific knowledge both for installing and operatingthe equipment, as well as producing applications and contents.Some large institutions – public or private – have technological apparatuses that makepossible to do experiments in this area. However, the lack of applications available for thelearning process makes difficult to use such systems in teaching. The applications and thesystems must be as simple as possible so that it is viable its popularization. There are somecommercial solutions, not so expensive, that offer support and specialized training foradopting VR systems. However, they are still expensive enough to exclude the systemadoption by the great majority of the institutions that have limited budgets. Therefore, thesecommercial solutions are restricted to small groups of private schools or isolated projects ofpublic institutions.The largest difficulty for the popularization of VR in education consists in eliminating thehigh costs and the cultural barrier simultaneously.This study will explore the stereoscopy concepts, as well as its different techniques which hasthe aim of improving the teaching and learning process in classrooms or laboratories. It is anexcellent VR tool to be used in education.This paper also shows, through a case study, that it is possible to have a low cost system,overcoming cultural barriers. Stereoscopy enables the students to experience a feeling ofimmersion into real environments. In the case study discussed herein real videos were usedwith three-dimensional (3D) projection, but it is possible to produce 3D virtual environmentswith computer graphics tools, like simulations and games. 1(11)
  2. 2. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, Brazil2 Virtual Reality: devices and toolsThe interest in using VR in education has grown in the last decades due to the technologiesimprovement and its popularization, which allow research and development of many systemsfocused in teaching and learning process [1, 3].The VR term may have several meanings. It can be defined as a software interface that usesvirtual environment generated by a computer, in real time, providing the user with a feeling ofimmersion into an artificial environment, allowing navigation in the virtual world and themanipulation of virtual object in an intuitive way. In another meaning, a VR system canprovide images of real environments to be used with stereoscopy techniques, increasing thespatial sensation of the user when watching with total or partial immersion. Some VR systemsuse a visualization and control helmets (HMD – Head Mounted Devices), data gloves,electronic controls (joysticks), real size projections and rooms with projection screens all overthe walls. Another possible feature is the inclusion of floor and ceiling, named Digital Cave orIPT – Immersive Projection Theater [1]. In Brazil, the first digital cave was built in theUniversity of Sao Paulo (USP), by the Laboratory of Integrated Systems (LSI) of thePolytechnic School (EPUSP). USP digital cave has five projection faces (four walls and thefloor) [4].The VR is based on Immersion, Interaction and Involvement [2]. Immersion is the feeling ofdigital presence in the virtual environment. Interaction is guaranteed by the availability of 3Dinput devices to allow the user handling of virtual objects. Involvement is related to thedegree of motivation that a person shows while doing a certain activity. It may be both inpassive terms, like reading or watching a video, and active, where interaction andmanipulation of objects in the virtual environment occurs. A good example of this use is thetools for education available in the areas of biology and geography based on interactive 3Dvirtual projection systems [5].The biggest obstacles for adopting VR have not been the technological limits, but the highcosts of developing and implementing the systems. Generally, the cost of building VRsystems is high, which limits them to institutions with large budgets. The HMDs are not soexpensive, (with costs ranging from USD 1,000.00 to USD 4,000.00, at 2004 prices) [6].However, purchasing many of them so that a large group can interact in the same applicationcan be impracticable. The active digital caves allow an interaction of many users. But besidesscreens and projectors, each user needs to wear an active stereo shutter glasses that consist oftwo Liquid Crystal Displays (LCDs). These shutter glasses work in a frequency between 120Hz and 150 Hz in an alternate way to get the 3D effect.The sum of all the necessary material for making a good cave exceed USD 1 million, at 2004prices [6], restricting its acquisition to few institutions.The recent technical advances in IT (Information Technology) equipments available in themarket – specially regarding to the performance of processors, graphics cards, high storagecapacity, projector technology, which offers reduced size equipment, low energy consumptionand bright increase – allow low cost VR systems to be used in many institutions, even in thoseones with restricted budgets for investments.Low cost systems use PCs on free platform (Linux), public domain tools and open sourceapplications. They use the stereo passive technique (see description in sections 3.2 and 3.3) toget 3D visualization. This allows not only the cost reduction and increasing of teaching andlearning concepts, but also the technological diffusion in society [3]. The estimated cost ofsuch systems ranges from USD 10,000.00 to USD 60,000.00, at 2004 prices [6].An important example of this system is the Geowall project [7], which is used for thescientific visualization of geological data. Another interesting project is the AnatomI 3D [8]:an anatomy atlas based on VR that interactively presents 3D structures of the human body 2(11)
  3. 3. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, Braziloffering monoscopic and stereoscopic visualization. Monoscopic means that the same imageis shown to both eyes. Stereoscopic visualization has three ways: anaglyphs, polarized light orlight shutter. These stereoscopy techniques are further explained in the following topic. TheAnatomI 3D is a free platform based on public domain tools, which can integrate structuresand descriptive texts for anatomy studies. It is structured on a VirtWall [9] platform, which isa stereoscopic projection system of simulated environments built with computer equipment.VirtWall’s philosophy is the adoption of low cost tools and devices, which allows theimmediate use of advanced technologies by smaller institutions.A good concept of VR applications with the aim of allowing portability between platforms iscalled overlapped abstraction layers concept [10]. It includes layers for graphic hardware,operational system, graphic library, VR packages and VR applications. Many libraries andopen source tools can be used in this application development, such as OpenGL, Open SceneGraph (OSG), VR Juggler, Blender, VRML and ImageJ. Table 1 illustrates the concept ofoverlapped abstraction layers, with the classification of some examples for each layer. Table 1: Description of the overlapped abstraction layers with some examples of the systems available in the market (taken from [10], modified by the inclusion of examples) Layer Examples USP Digital Cave, Geowall, AnatomI VR Applications 3D, VirtWall, Construct 3D 3D design, animation and ImageJ, Blender, 3DS Max, Shout 3D, modeling Software Poser, Canoma, Spazz 3D, VRML C, C++, Java, VB.NET, ASP.NET, VR Packages Development Languages Shockwave, Flex, Delphi, ECMAScript Quick Development Alice 3D, World Up, Internet Space Packages Builder and EON Studio Graphic Library OpenGL, DirectX Operational System Linux, Windows Graphic Hardware Graphics Cards, VGA Cards, GPUs3 Stereoscopy in VR3D images visualization in VR is obtained by stereoscopy. This is a human active effect,because it is not present in an isolated image. It is interpreted through binocular vision,directly by the human brain [11, 12]. To recover this effect, two different images must begenerated, one for the left eye and another one for the right eye. Each image must be obtainedwith slightly different capture points, causing the parallax effect. The difference betweenthese capture points must be similar to the one obtained with the human eyes separation.The studied techniques of stereoscopy are: active stereo technique, obtained with the use ofLCD shutter glasses, and the passive stereo technique, obtained by anaglyphs or with lightpolarization eyeglasses. These techniques are described bellow.3.1 Active Stereo with Shutter GlassesThe active stereo technique is commonly used in digital caves. Transparent LCD eyeglassesare used, which work as a shutter, called shutter glasses (see figure 1). The systemsynchronizes the image seen by each eye with the projected image, in order to separate leftand right eye images. 3(11)
  4. 4. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, BrazilUSP digital cave has 24 computers in a cluster to generate 3D images in real time. Five 3m ×3m walls were built, as shown in figure 2 [13]. Figure 1: LCD shutter glasses for the active stereo technique (taken from [2])Image refresh rate must be at least 120 times per second (120 Hz) so that the user does notnotice the scintillation effect, alternating 60 times per second (60 Hz) for each eye [13]. Theprice of each shutter glasses is USD 500.00 and each high-speed projector start prices fromUSD 10.000,00 [6]. The active stereo technique presents the best results, but it is the mostexpensive. Figure 2: Images from the USP digital cave with the active stereo technique (taken from [13])3.2 Passive Stereo with AnaglyphsAnaglyphs are scenes obtained by double image – each one from a different point, printed intwo contrasting colors that produce depth illusion. It is necessary to use simple plasticeyeglasses and the appropriate color lens for each eye (red and blue). It uses only oneprojector, since the images can be overlapped by software such as ImageJ [14], free and opensource public domain software. It is the simplest and the most economic of all the VRstereoscopy techniques, but the results are reasonable, because color loss will occur. Observean image created with the anaglyphic technique, in figure 3. 4(11)
  5. 5. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, Brazil Figure 3: Image with the anaglyphic technique and eyeglasses (taken from [12])3.3 Passive Stereo with Light PolarizedIn the passive stereo technique with light polarization, two common projectors are used tocreate different images for the left and the right eyes. Filters with light polarization (verticaland horizontal polarization) are placed over each projector’s lens. Every user must weareyeglasses with polarized lens, so that each eye can see only the corresponding image.A polished metal projection screen (aluminized) is necessary to preserve the lightpolarization, since normal screens are opaque and spread the light in different directions,destroying the light polarization. Figure 4: 3D projection device with light polarization (taken from [6])The most difficult part in configuring the system is the projector alignment. It is importantthat the images corners in each projector meet. However, to overlap the two images on onescreen, it is generally necessary to pile the projectors (see figure 4) and then incline them untilthe projections are aligned. This results in an image with keystone effect, projecting atrapezoidal format image instead of a rectangular one. Some projectors allow imageadjustment that can correct this effect. Without the correction the image is still acceptable, butit loses quality and can strain the eyes of the most sensitive people after a few minutes. It isalso important to balance the intensity and the colors of both projectors, which, preferentially,must have the same model. Difference in intensity and colors can cause a disturbing effect on 5(11)
  6. 6. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, Brazilthe eyes. If the adjustment is not aligned, the user can suffer collateral effects, such asheadache and nausea, causing even faints.The passive stereo technique with light polarization is not the less expensive, but it presentsthe best cost-benefit rate when compared to the anaglyphic and active stereo techniques. Eachprojector costs around USD 500.00, the aluminized screen costs about USD 50.00, thepolarized filters for the projectors is USD 25.00 and the eyeglasses cost around USD 3.00.Considering a system for at least 50 users, two projectors are necessary, one screen, twofilters and 50 eyeglasses, totalizing an investment, only for the projection part, around USD1,250.00 [6], 2004 prices.4 VR in EducationThe use of VR in education has drawn much attention. In 1998, Cristine Youngblut producedfor IDA (Institute for Defense Analysis) a report with over 70 projects of VR application ineducation [1]. Electronic journals appeared, such as “VR in Schools”, and special editions injournals, as Presence, from June 1999. The developed prototypes and applications were builtto specific groups (children, university students, adults, students with physical or cognitiveincapacities), covering a wide range of didactical content (science, arts and others) andpedagogical aims (impulse to learning, instructions, training, rehabilitation and skillsdevelopment).An experiment was conducted by Cliburn [6] with a VR system based on light polarization.Two groups of eight students had a lecture about astronomy. One group had an interactivetour of the solar system using a VR system. The other group had lessons in the same subjectin a lecture format. Right after, a questionnaire was given to the groups. The group that hadused the VR system got an average of 9.8, while the other got 8.9. The group that had only thelecture got an average of ten after watching the content in VR system. Cliburn did notconsider the result as conclusive, due to the reduced number of students, but he considered it asample of results that can be obtained in larger studies.VR applications in education can be used in many areas [15], like medicine, training ofanatomic structures and distance surgeries. Another area of great interest is the industry,where applications in oil and gas exploration are studied by many professionals using 3Dmodels projected in VR, such as geologists, geophysicists, and reservoir engineers. Petrobras,the biggest oil exploration and production Brazilian company, has about thirteen VR centersspread around its units. Embraer, an important aircraft manufacturer Brazilian company, usesa great VR room for trainings in some airplanes. Another example is in the science andmathematics field, where students have access to 3D models for learning in physicsexperiment (Newton World), chemistry (Maxwell World) and geometry (Construct3D [16])[15].5 Case StudyThis case study assessed the stages and processes of a 3D video production since the imagesacquisition, edition and projection in the classroom. For doing so, low cost equipment wasused. It is important to emphasize that some of the equipment were provided by LSI/USP.Even with so many sources of research, it is difficult to collect detailed material about 3Dvideos production. The commonly approached aspects refer to the 3D photography. Thewebsites, and show this typeof domain in the photography field. However, at, it is possible to findsome software examples and videos on 3D video production. 6(11)
  7. 7. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, BrazilAmong the possible ways of producing 3D video, one that uses a stereoscopic special lenswill be focused here. It eliminates the necessity of using two cameras for generating thestereoscopic images, that is, one image for the right eye and another for the left one [17].In this process, a second special lens is used, which is composed of two LCD shutter glasses,a prismatic beam splitter and an adjustable mirror that is connected to the camera lens. Thesespecial lenses are synchronized by a cable to the camera, under the same frequency of theequipment according to figure 5.This way, when the even field of the interlaced image is being generated, the shutter hindersthe light coming from the mirror entrance and when the odd field is being generated, only thismirror light is recorded into the tape by the camera.The equipment also provides a convergence of the distance adjustment between the cameraand the objects through its mirrors, called parallax effect. The mirrors are placed at 2.2” (56mm) far from each other, a slight lesser distance than the mean distance between humanpupils, which is 2.6 (66 mm)[17].It was possible to make the stereoscopic images capture with this system, allowing a simpleprocess of video production, because the images remain recorded on a tape. It was used ahome video camera, with digital recording system (mini-DV) and digital output video(firewire). For the videos editing, it was used a laptop computer with firewire interface,enabling the capture of tape images directly from the camera to the hard disk, without qualityloss. After the scenes selection, the edited material was copied back to the tape, using thesame camera.For the 3D video projection were used: two low cost projectors, one aluminized screen, twopolarized light filters, one 3D video decoder, and the camera for the video player.Two 3D videos were produced on traffic education. The first one was a video, about threeminutes, showing to new drivers a sequence of activities and tools needed for a car tireexchange. In the second production, it was used a moving car whose objective was todemonstrate to future drivers (children) how to deal with the city traffic flow (to deviate fromother vehicles, to turn around squares, to pass obstacles and turnouts). Figure 5: System for the production of low cost 3D videos (extracted from [19])The first video produced could not be used for exhibition, because the convergence of thedistance adjustment between the camera and the objects adjustment was greater than needed.It caused the excessive increasing of parallaxes effect, resulting in images too separated to get 7(11)
  8. 8. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, Brazilthe stereoscopic effect. This made difficult the 3D images visualization, causing visualdiscomfort to the viewers when they tried to see the images superposed by the projectors.The second video was exhibited for two groups of 15 students. In the first class, 12 from 15students reported some immersion feeling. In the second group, 14 students visualized 3Dscenes, as well as objects being projected outside the screen.The fact that some students do not achieve the visualization of 3D scenes is related tophysiologic and psychological factors of each one, which will not be approached in this study.The conclusion is that the gotten result was quite satisfactory and promising.5.1 Investment Amounts for 3D Videos ProductionTable 2 lists the materials used in this case study, investment amounts, and detaileddescription of equipment and materials needed for a video with low cost stereoscopyproduction to be implemented in learning institutions. In this budget neither the services northe place where the exhibition will take place (classroom or auditorium) were considered. Table 2: List of equipment used for 3D videos production Equipment/Materials Manufacturer Model Price (USD)* Recording 3D Lens NuView SX2000 500.00 8mm Camera Sony - 450.00 AC Plugs - - 10.00 2 tapes Sony miniDV 10.00 BNC/RCA cables - - 10.00 2 batteries for the camera Sony - 60.00 Subtotal 1040.00 Edition Laptop computer with firewire Dell Latitude 2500.00 interface Software for video edition Adobe Premiere 6.0 350.00 Subtotal 2850.00 Exhibition 8mm Camera (for Player) Sony - 450.00 3D video decoder NuView - 575.00 BNC/RCA cables - - 15.00 Aluminized projection screen - - 300.00 Two portable projectors InFocus LP120 2500.00 Subtotal 3840.00 TOTAL INVESTMENT 7730.00*Estimated amounts in 2006 Brazilian market.5.2 Amounts of Expenses for 3D Videos ProductionIn order to present a possible reduced budget for the video production, the same service costwith estimated prices is showed in Table 3 for the Brazilian market, which was calculatedwith the experience applied for this production. The production of a 3D video with 15 minutes 8(11)
  9. 9. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, Braziltakes from 4 to 6 men/hours for field images collection, 2 men/hours for elaborating of thescript, 3 men/hours for video edition and 1 men/hour for the exhibition in classroom. Table 3shows the costs for executing a VR project with the estimated prices for the equipments(rents) and the services. Table 3: List of services performed in the case study Service/Location (daily) Price (USD)* Recording costs Lens 3D NuView SX2000 75.00 Camera 8mm with parts and cables 50.00 Cameramen / team per diem 75.00 Material for settings and others 75.00 Subtotal 350.00 Edition costs PC for video edition 100.00 Editor / producer per diem 100.00 Subtotal 200.00 Exhibition costs Projection system (Projectors, screen, 3D decoder) 150.00 Mounting technician per diem 100.00 Subtotal 250.00 TOTAL EXPENSES 800.00 *Estimated amounts in 2006 Brazilian market.6 ConclusionThe feasibility of VR use in education is, at first sight, related to the decreasing of theequipment costs that is occurring every year. Once the costs barrier is surpassed, it remainsthe cultural one, encouraged by the lack of specialized knowledge on VR and by the smalloffering of practical applications that can be used by learning institutions all over the country.The equipment cost decrease and the alternate solutions such as 3D videos production throughthe light polarization technique shall help the dissemination of VR in educational institutionswith limited budgets. In this paper, it was used the technique of passive stereoscopy with lightpolarization. This presents the best cost-benefit rate for the 3D videos production.During the production, a certain difficulty for adjusting the distance was observed, whichinfluences in the parallaxes effect with the 3D lens during the process of images recording.This can cause visual discomfort to the viewer, such as the one occurred during the firstproduction. In the second case, we got a more accurate adjustment, increasing the viewer’simmersion feeling into a 3D environment under total moving.The production of 3D educational contents requires special technique, equipment and care.In this case study, during the first exhibition, 12 of 15 students who watched the projectionrelated an immersion feeling. In the second exhibition, 14 students did it. The productionscarried out in this work allowed the assessment of the technique, the difficulties andproduction costs. Since the results are promising, the use of low cost VR systems in learninginstitutions is considered as a real possibility. 9(11)
  10. 10. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, BrazilReferences:[1] Youngblut, C.: Educational Uses of Virtual Reality Technology. Alexandria – VA – USA: Institute for Defense Analysis, 1998. 114p. IDA Document D-2128. Available at: <>. Accessed on Nov. 14th, 2006.[2] Netto, A. V.; Machado, L. S.; Oliveira, M. C. F.: Realidade Virtual - Definições, dispositivos e aplicações. REIC – Revista Eletrônica de Iniciação Científica, v. 2, n. 1, 2002. Available at: <>. Accessed on Nov. 19th, 2006.[3] Tori, R. O Virtual que marca Presença: Revista Brasileira de Aprendizagem Aberta e a Distância, São Paulo – SP – Brazil, 2003. Available at <>. Accessed on Nov. 8th, 2006.[4] Santos, E. T.; Zuffo, M. K.; Netto, M. L.; Lopes, R. D.: Computação Gráfica: Estado da arte e a pesquisa na USP. In: Simpósio Nacional de Geometria Descritiva e Desenho Técnico, 15., 2001, São Paulo – SP – Brazil. Proceedings... São Paulo – SP – Brazil: EDUSP. 2001, p. 3.[5] Prodigy3D: SP, Brazil. Virtual Reality Software for educational institutions with 3d computer graphics images. Available at: <>. Accessed on Nov. 25th, 2006.[6] Cliburn, D. C.: Virtual Reality For Small Colleges. The Journal of Computing Sciences in Colleges, Hanover – IN – USA, v. 19, n. 4, 2004, p. 28-38.[7] Belleman, R.; Stolk, B.; Vries, R.: Immersive Virtual Reality on commodity hardware. In: Lagendijk, R. L.; Heijnsdijk, J. W. J.; Pimentel, A. D.; Wilkinson, M. H. F. (eds.). Proceedings of the 7th annual conference of the Advanced School for Computing and Imaging, 7., 2001. Proceedings... Heijen – Netherlands: ASCI, 2001, p. 297-304, ISBN 90-803086-6-8. Available at: < Accessed on Nov. 14th, 2006.[8] Monteiro, B. S.; Valdek, M. C. O.; Cunha, I. L. L.; Moraes, R. M.; Machado, L. S.: AnatomI 3D: Um Atlas Digital Baseado em Realidade Virtual para Ensino de Medicina. In: SVR - Symposium On Virtual Reality, 8., 2006, Belém – PA – Brazil. Proceedings… Belém – PA – Brazil. 2006.[9] Moraes, R. M.; Machado, L. S. e Souza, A. C. M.;: VirtWall: A Concept of Low-Cost Virtual Wall for Immersion in Virtual Reality. In: SVR - Symposium on Virtual Reality, 6., 2003, Ribeirão Preto – SP – Brazil. Proceedings... Ribeirão Preto – SP – Brazil. 2003. p. 383-385.[10] Calonego Jr. N.; Garcia M. B.; Meiguins B. S.; Netto, A. V.; Cateriano P. S. H.: Modelagem e programação de ambientes virtuais interativos. In: Tori, R.; Kirner, C.; Siscoutto, R. (eds.). Fundamentos e Tecnologia de Realidade Virtual e Aumentada. Preliminar book VIII Symposium on Virtual Reality. Belém – PA – Brazil: SBC, 2006, v. 1, p. 98-108, ISBN 85-7669-068-3.[11] Raposo, A. B.; Szenberg, F.; Gattass, M.; Celes, W.: Visão Estereoscópica, Realidade Virtual, Realidade Aumentada e Colaboração. In: Andrade, A. M. S.; Martins, A. T.; Macêdo, R. J. A.; (eds.). Congresso da Sociedade Brasileira de Computação, 14., 2004, Brazil. Proceedings... Brazil: SBC, 2004, v. 2, XXIII JAI - Book, cap. 7, p. 289 – 331, ISBN 85-88442-95-7.[12] Siscoutto, R. A.; Szenberg, F.; Tori R.; Raposo R.; Celes, W.; Gattass, M.: Estereoscopia. In: Kirner, C.; Tori, R. (eds.). Realidade Virtual: Conceitos e Tendências. Preliminar book SVR 2004. Brazil: SVR, 2004, cap. 11, p.179 – 201, ISBN 85-904873-1-8.[13] Zuffo, M. K.: A convergência da realidade virtual e Internet Avançada em novos paradigmas de TV Digital Interativa. 2001. 91p. Free-teaching thesis, EDUSP, São Paulo, Brazil, 2001.[14] ImageJ - Image Processing and Analysis in Java.: EUA. Software developed by National Institutes of Healt from USA government. Available at: <>. Accessed on Nov. 15th, 2006.[15] Cardoso, A.; Lamounier, Jr. E.: A Realidade Virtual na Educação e Treinamento. In: Tori, R.; Kirner, C.; Siscoutto, R. (eds.). Fundamentos e Tecnologia de Realidade Virtual e Aumentada. Preliminar book VIII Symposium on Virtual Reality. Belém – PA – Brazil: SBC, 2006, v. 1, p. 304- 312, ISBN 85-7669-068-3.[16] Kaufmann, H.; Schmalstieg, D.; Wagner, M.: Construct3D: a Virtual Reality Application for Mathematics and Geometry Education. Education and Information Technologies, London, England, v. 5, n. 4, p. 263-276, 2000.[17] Alves, A. O.; Tommaselli, A. M. G.; Galo, M.: Avaliação do sistema câmara de vídeo + nu-view para reconstrução de superfícies à curta distância. Boletim de Ciências Geodésicas, Curitiba – PR – Brazil. v. 8, n. 2, p. 3-19, 2002, ISSN: 1413-4853. 10(11)
  11. 11. Conference ICBL2007 May 07 - 09, 2007 Florianopolis, BrazilAuthors:Antonio, Carlos O. Amorim, Master in Computer Engineering, PhD Student,EPUSP, LSI/PSI, PAD,158, Prof. Luciano Gualberto Avenue, trav.3, ZIP: 05508-900, São Paulo-SP-Brazilacoamorim@pad.lsi.usp.brRodrigo, Dias Arnaut, Computer Engineer, Master Student,EPUSP, LTI/PCS,158, Prof. Luciano Gualberto Avenue, trav.3, ZIP: 05508-900, São Paulo-SP-Brazilrodrigo.arnaut@poli.usp.brSérgio, Takeo Kofuji, Master and PhD in Electronics Engineering,EPUSP, LSI/PSI, PAD,158, Prof. Luciano Gualberto Avenue, trav.3, ZIP: 05508-900, São Paulo-SP-Brazilsergio.kofuji@poli.usp.brAnna, Helena Reali Costa, Master and PhD in Electronics Engineering,EPUSP, LTI/PCS,158, Prof. Luciano Gualberto Avenue, trav.3, ZIP: 05508-900, São 11(11)