Optimizing the Reading and Interpretation of Topographical Maps by the Implementation of Augmented Reality Technology

Optimizing the reading and interpretation of topographical maps by the implementation of Augmented Reality technology

CLGE students’ contest 2014 Category: GIS, Mapping and Cadastre

Submited by: Sandra Uceda Queirós

Bachelor’s Degree Thesis

carried out in order to obtain the “Bachelor’s Degree in Geomatics and Topography Engineering” under the supervision of Dr. José Manuel Valle Melón and Dr. Álvaro Rodríguez Miranda at the Laboratory for the Geometric Documentation of Heritage (LDGP), University of the Basque Country (UPV-EHU), Spain, 2014.

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CLGE students’ contest 2014 Sandra Uceda Queirós

ABSTRACT

In this paper the possibility of implementing a new actor in the areas of geomatics and archaeology is considered; Augmented Reality (AR). It is not meant to be an alternative, but rather a complement to the methods that are currently being used, emphasizing the representation, visualization and divulgation phases.

It is based on the idea that this technology could contribute to simplify and universalize the interpretation of paper maps (real environment), supposing that it could be used as a bridge between them and their corresponding digital 3D representations (virtual environment). Thus, the current study aims to obtain an augmented environment in which a virtual object seems to coexist with the real world. It is analyzed how due to this connection, results are more attractive, intuitive and useful, optimizing reading and interpretation of complex maps.

Several tests have been carried out using different types of maps and models (wireframes and meshes). Based on these data, some applications have been developed, executable in various devices and platforms, with free software packages (AR-media, Vuforia SDK and Metaio Creator). Through an essentially qualitative approach, and focusing on appearance, stability, geometry or distortion of the results, an overview of the possibilities that this technology currently offers is provided.

Finally, on the one side, a comparative summary of the performance has been included, involving the initial data and the software used. On the other side, a general methodology for the integration of Augmented Reality in the printed maps is proposed.

Key words: Augmented Reality, augmented maps, heritage, 3D models, visualization, tracking.

1. INTRODUCTION

Augmented Reality (AR) can be considered as the digital version of the conventional physical miniatures, characterized by its flexibility, possibility of adjusting and interaction (Fernández Álvarez, A. J., 2010). The concept itself has developed over time, mainly influenced by technological advances.

This project has been carried out, pretending to avoid limiting AR to specific technologies, considering the term as a system that combines real and virtual worlds, allows interaction in real time and is registered in three dimensions (Azuma, 1997). It consists of the integration of 3D virtual objects into the real world as observed by the users, augmenting this reality with additional information.

CLGE students’ contest 2014 Sandra Uceda Queirós

Augmented Reality is an intermediate state between the limits of the Reality – Virtuality (RV) Continuum (Figure 1) (Milgram, P. & Kishino, F., 1994). Based on the amount of virtual environment, a classification is established, starting from the completely real world, through the so-called mixed reality (MR) until the virtual world. The main mixed reality states are augmented reality (AR), where reality is augmented with virtual objects, and augmented virtuality (AV), where virtuality is augmented with real objects.

Figure 1. Reality – Virtuality (RV) Continuum with explanatory images (Milgram, P. & Kishino, F., 1994; Gerd Bruder, et al., 2009).

Knowing that AR integrates and fusions the reality of the moment with some virtuality, using a software which is able to recognize different shapes and allows global positioning, it is intended to register the position of a point of view and the location of the viewer in the real world, with the aim of superimposing the desired virtual element over a concrete and known position. In this project, the real objects, where the virtual element will be added, are the architectural or topographical printed maps. It is considered that being able to visualize, manage and somehow interact in real time with a virtual 3-D model that grows on a paper map would represent great progress in the areas of representation, interpretation, visualization and diffusion.

Three-dimensional representations have always been the key to reproduction and understanding of significant elements and, as a result of the digital era, they started to be virtual. Thanks to technological advances, its development and visual appearance continues to be optimized, so they are becoming more precise and apparently real. These kinds of representations are the most tangible and evocative ones, and the level of training needed for their interpretation is the lowest, which is the reason why they are an excellent method of diffusion (Valle Melón, J. M., 2007).

Maps are the graphic representation of a project, describing it exhaustively, in detail and scale, pretending to make it visually understandable as a whole. These documents are and have traditionally been considered to be the result of the geometric documentation. They were designed to be a database

CLGE students’ contest 2014 Sandra Uceda Queirós

as well as a way of representation (MacEachren & Kraak, 2000). Nevertheless, it is known that visualizing and analyzing technical information from two-dimensional drawings requires the performance of complex cognitive processes, including perception, orientation, spatial rotation and size transformation of the different elements. Due to these cognitive processes, reading and interpreting maps often becomes a slow and tiresome job.

Consequently, why is it not taken advantage of the AR technology as a possible way of fusion? Connecting different ways of expressing information, such as texts, plans or maps, 3D models, animations or structured data, will surely allow to obtain more complex, realistic, dynamic and intuitive visualizations. Creating an augmented environment by the combination of 2D drawings (real environment) and corresponding 3D representations (virtual environment) could contribute to improve the interpretation of the information that intends to be transmitted.

2. OBJECTIVES

By making several tests, it is expected to obtain an overview of the possibilities that the variety of free software solutions available on the market provides, establishing also a specific operating methodology for each one of them. For this purpose, information from different projects was gathered, including different types of three-dimensional digital elements (Table 1) and their corresponding maps.

PALEONTOLOGICAL STONE DOOR BASILICA DOLMEN SITE

Mesh with photographic Simple wireframe model Complex wireframe model Coloured mesh texture Table 1. Type and visual appearance of the projects that have been used. (LDGP, 2004, 2011, 2008)

CLGE students’ contest 2014 Sandra Uceda Queirós

3. IMPLEMENTING AUGMENTED REALITY (AR) IN MAPS

3. 1. VISUALIZATION TECHNIQUES

As defined above, combining real and virtual images is fundamental, and in this task the device plays an important role. When an AR system is developed, unlike the VR, it is not intended to replace reality with the virtual element, but that both coexist in a same environment.

Devices that allow viewing the real world and a virtual object or computer-generated graphics overlapped are necessary for visualizing an augmented reality scene, with all the difficulties involved. Depending on the kind of application that is attempted to be created, the generation of AR environments requires some of the next hardware components and elements (Torres, D. R., 2013):

- Visualization system, generally through a screen or display. - Tracking system. Outdoors via GPS and indoors with ultrasound, magnetic and optical technologies. - Recording or registration unit (camera). - Processor capable to carry out analysis, mix and rendering of the video image in real time. - Virtual element (3D model) (Table 1) and the real element where the virtual should be visualized (printed maps).

Even though the most common devices used for AR are visual, they are currently starting to be complemented with sound, smell, taste and touch experiences. When more than one display is combined, the system is called multimodal. The range of displays increases parallel to the progress in the fields of optic and computer science. At present, it is possible to use from the traditional computer with its screen and webcam, to the newest devices, such as tablets, smartphones or video game consoles. Among others, the most commonly used systems are optical see-through (OST), video see- through (VST), monitor based AR, spatial AR o projective AR (Fernández Álvarez, A. J., 2010).

3. 2. SOFTWARE

In the past decade, a variety of specific software for creating AR applications has been launched, for both developers and non-expert users, including also some under GPL (General Public License). This has led to a growth in involvement and participation of people with this technology in many fields of knowledge.

ARToolKit is the first known software or specific library for AR, released by the University of Washington HIT Lab and presented at SIGGRAPH. It solves two key problems: tracking and interaction with the virtual object (Kato, H. & Billinghurst, M., 1999). After that, new platforms like

CLGE students’ contest 2014 Sandra Uceda Queirós

MXRToolKit, FLARManager, ARTag, Studierstube, etc. appeared. Libraries where real environment recognition is possible also exist, for example BazAR. Finally, the recent APIs (Application Programming Interfaces) and SDKs (Software Development Kits) came up, as a package or software component for various platforms like Wikitude, Layar, Qualcomm Vuforia, Metaio, Total Immersion D’fusion y String. All of them work in a different way; some are based on the real image or object recognition, some others on geopositioning systems and the best ones can create both cases (Torres, R. D., 2013).

The platforms chosen in the current study for the implementation of augmented reality on the previously described data are the AR-mediaTM plugin for Trimble SketchUpTM, the Qualcomm® VuforiaTM SDK extension for Unity 3D and Metaio Creator.

3. 3. TRACKING

Another key aspect of the technology of augmented reality concerns the proper tracking, which includes recognition, positioning, recording and monitoring process of a given virtual element in the real environment. With the aim of obtaining a realistic augmented environment, the objects from the real and virtual worlds must be accurately combined, requiring the correct identification of various marks or patterns, the position of the involved objects and tracking of the user’s field of vision. Based on the nature of various algorithms used in the different programs, different type of markers can be differentiated and recognized for optical tracking (Koch, C., Neges, M., König, M., Abramovici, M., 2014):

Figure 2. ID marker, QR code marker, barcode marker, picture marker, markerless 2D (borderless) and markerless 3D (borderless) (http://dev.metaio.com/sdk/tracking-config/optical-tracking/ accessed May 2014)

In order to obtain a better knowledge on this topic, it was decided to start testing the functionality of one of the available models in the easiest way, i.e., by growing a simple wireframe model over the default AR-media marker. However, its original size seemed quite big for this project’s goal (7,5cm x 7,5cm), so it was reduced several times before testing its functionality.

CLGE students’ contest 2014 Sandra Uceda Queirós

Figure 3. Default marker (7,5cm x 7,5cm), first reduction (4cm x 4cm) y second reduction (3cm x 3cm).

It was proved that, under similar conditions (brightness, speed of movement, etc.), the tracking and stability was acceptable and similar in all cases.

After checking that the virtual element doesn’t need to grow exactly over the marker, the first map composition was created (Figure 4 (left)). Before making the superposition in any free area of the map, factors like suitable size, strategic position and number of markers need to be established.

Unfortunately, the first obtained result was not appropriate (Figure 4 (right)). When the camera was rotated around the map or the map was moved while keeping the camera still, depending on the angle or distance between the marker and the camera, the virtual model became unstable, not accurate, vibrated, raised on the remote corners and did not stay stuck on the paper map, as intended.

Figure 4. Floor plan of the Basilica with one marker (left) and execution of the app. (right)

Specific values of these errors have not been measured, as it was noticed that they vary depending on the camera perspective, distance, speed of movement or environmental brightness. Nevertheless, in order to improve the obtained results, the use of two different markers linked to the same object and located in opposite corners of the plan was tested. It could be verified that the two main problems were solved: first, the camera’s freedom of movement increases, allowing a complete rotation around the building while keeping at least one marker in view, and second, the stability of the virtual model augments when both markers are detected and tracked simultaneously. These avoid having any kind of perspective problems and permit increasing the distance between the printed map and the camera objective.

CLGE students’ contest 2014 Sandra Uceda Queirós

Even though the described approach delivers good results, it requires printing some markers on the original map. In order to arrive at a more agile and flexible practical application, it is proposed to use a transparent sheet with printable rough surface superimposed on the plan, where relevant markers would appear (Figure 5 (left)). This solution, on the one hand, avoids needing to modify original and finished maps, keeping them intact, especially because the user will not always be able to modify the original version or the digital one might not be available. On the other hand, preparing a template ready to use in several and similar projects could reduce both costs and time involved in the development.

Figure 5. Floor plan of the Basilica with two markers on the transparent sheet (left) and execution of the app. (right)

To take the process a step forward, the idea of using any kind of image or customized marker as part of the real environment became attractive and viable in some other platforms (Vuforia SDK and Metaio Creator), aiming to get rid of the inconvenience of needing to use and depend on a predefined marker, as it has been done until now. Specifically, it is considered to use the drawing of the map as a marker, avoiding the need of modifying it by adding any specific pattern.

Vuforia SDK offers an online tool (Target Manager) that allows creating personalized markers and rating their effectiveness (detection and tracking of the image), providing the user an estimation of the performance by the assignation of a number of stars (0 min. quality and 5 máx.). Besides, the location of the features found can be visualized (yellow crosses).

Figure 6. Features found in three basic shapes (https://developer.vuforia.com accessed June 2014)

Referring to the marker’s quality, not only the number of features is significant, but also their uniform and spread out distribution, allowing the camera to track the image from more angles and distances without loosing the connection. It is important to avoid repetitive patterns and symmetric textures,

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which cannot be recognized by the platform (Simonetti Ibañez, A. & Paredes Figueras, J., 2013). In addition, developers suggest not using markers whose rating is lower than three stars. Most of them can be changed and it is recommended to increase the features by improving feature distribution, increasing local contrast and thickness of lines or eliminating repetitive patterns.

First of all, the reaction of an own text marker was analyzed (Figure 7). This idea came because using text as a marker could allow virtual models grow when pointing the device to the title or legend of the map, loosing the dependence on a marker.

Figure 7. Rating and features of text as a marker.

Furthermore, having observed that the idea of growing a digital 3D model exactly on the drawing of a floor plan begins to be viable, the reaction and rating of the plans is followed in sequence. Starting with the dolmen which, as indicated, corresponds to a coloured mesh:

Figure 8. Rating and features of the floor plan of the dolmen as a marker, original (above) and modified (below).

As it can be seen in the figure above, prior to rejecting the idea of using a floor plan, the first obtained result (Figure 8 (above)) was improved by following the guidelines given by the platform developers, described above. Regarding the dolmen as a valid example (Figure 8 (below)), the quality of an orthophoto of the paleontological site is evaluated below.

CLGE students’ contest 2014 Sandra Uceda Queirós

Figure 9. Rating and features of the paleontological site orthophoto as a marker, original (above) and modified (below).

Due to the quantity of stars given and large number of features or fiducial points recognized (Figure 9 (below)), the tracking works correctly and even allows users to visualize the scene from a wide variety of viewing angles and directions, being able to perceive the scenes with depth in a clear and stable way.

Finally, unlike the applications created with Vuforia SDK, the environments created with Metaio Creator should pass through a platform where the content could be managed and the used markers stored (Metaio Cloud). Beyond this, the software offers an expanded range of possibilities in order to carry out the mentioned tracking: 2D images, 3D objects and three-dimensional environments. Besides, it has the additional advantage that after exporting the created scene, an image with some instructions and a QR code is automatically saved (Figure 10), allowing any user who has Junaio installed (a free AR browser), run the developed application.

Figure 10. Instructions and QR code that will be saved in the developers’ computer.

CLGE students’ contest 2014 Sandra Uceda Queirós

3. 4. USER – WAYS OF INTERACTION

The given Augmented Reality definition is based on three pillars, including the interaction in real time. This means that, apart from mixing reality and virtuality for obtaining a three-dimensional environment, it’s essential to have the possibility of interacting, which means that an interlink between the user and the superimposed digital elements while the application is running should exist.

Types of interaction are classified in various ways. On the one side, handling with virtual/real objects (allows moving real objects which are linked to the virtual ones), interaction based on the navigation (the user is able to take a tour around a concrete AR scene, being able to freely navigate through it) and interaction with other users (a collaborative environment where more than one user can interact at the same time) (Portalés Ricart, C., 2008). On the other side, a classification based on the type of input device used and the way it is employed, differentiating between the use of markers, body motion, low cost devices and multimodal interaction (Garrido, R. & García-Alonso, A., 2008).

Among the many options that the AR-media plugin offers, apart from optimizing the tracking or smoothness, some visual interactions have been tested during the viewer execution on a PC: wireframe mode, object/scene interaction (scaling up and down), layers/sequence management, clipping, sectioning, etc.

Figure 11. Wireframe mode (left.) and scaling (centre and right)

Figure 12. Layers management.

CLGE students’ contest 2014 Sandra Uceda Queirós

Figura 13. Clipping and sectioning (left and centre) and available clipping planes with their numbering (right).

4. RESULTS

After the analysis and research phase, the obtained results are of various kinds. First of all, a series of different applications have been created for each different project, with different software (AR- mediaTM plugin for Trimble SketchUpTM, the Qualcomm® VuforiaTM SDK extension for Unity 3D and Metaio Creator) and for several platforms (Windows, Mac, iOS and Android) (Figures 14, 15 and 16).

Wireframe model of the Basilica, growing on its floor plan:

Figure 14. Environment of the execution with PC (left) and screenshot of the obtained result (right).

Colored mesh of the Dolmen, growing on its floor plan:

Figure 15. Environment of the execution with a smartphone (1) and screenshots of the obtained results: Smarphone (Android) with Vuforia SDK (2), iPad (iOS) with Metaio Creator (3) and PC (Mac) with AR-media plugin (4).

CLGE students’ contest 2014 Sandra Uceda Queirós

Mesh with photographic texture of the paleontological site, growing on its orthophoto:

Figure 16. Environment of the execution with a smartphone (left) and sreenshot of the obtained result (right).

In addition to the shown applications, a methodology for the implementation of AR in plans has been developed. Following the initial available data (type of paper maps, 3D models, need for representation, class of device where the application will be executed, etc.), the steps to be taken and the required software have been described.

Moreover, in order to provide a fair idea of which software could generally be more adequate for each case, some attributes have been evaluated: the reduction of the original file size comparing to the created application, parameters involved in the development (import formats, user-friendliness, time and equipment needed, software price, etc.) and involved in the runtime (export formats, required brightness, simplicity, editable result, time and equipment needed, appearance, interaction possibilities, editable logo, motion-sensitive, etc.). Based on these characteristics and after making a comparative summary of the performance appreciated on each used software, Vuforia SDK has been the best rated, followed by Metaio Creator and AR-media. This was a simple basis used as guidance, but it has been regarded as effective in this first approximation.

5. CONCLUSIONS

The existence of several technical and economic possibilities available to integrate or fusion classical cartographic representations with virtual models has been clarified. In addition, the possibility to create personalized markers using the mentioned cartographic representations has also been proved. Looking forward, new features like three-dimensional markers or markerless environments should also be taken into account.

However, we are dealing with a very promising new dynamic geovisualization method that has a great development potential for heritage items and GIS data. This technology came to light about 20 years ago and it is developing and changing very quickly, which means that due to the scientific

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advancement and the significant amount of research that are being conducted, the current limitations will be sooner or later solved.

Augmented Reality is still an area of ongoing research and exploration, so watching the technology running still attracts our attention, but that does not mean that raising awareness and convincing the society, different authorities, clients or even teachers about its utility and potential should be easy.

Lastly, by way of example, some possible and relevant applications of the AR technology in areas near heritage or geomatics should be mentioned, being almost impossible to deny that they will give way to new lines of research: archaeological excavations, allowing to visualize hidden structures and make studies and interpretations in-situ; classic topography, making survey stakeouts easier by the virtual superposition of bases or geographically referenced landmarks; architecture, helping to develop, asses the feasibility and visualize results of particular projects; public organizations (city council, town hall, etc.), facilitating the localization of underground storage facilities or supply and sanitation networks, and of course for museology, tourism, education, etc.

It is interesting for future work, however, to carry out an economic evaluation together with some kind of statistical approach considering opinions and personal assessments of different groups of people and professionals, aiming to determine to what extent AR will satisfy users and its degree of implementation and efficiency in the short to medium term. We should be aware that in the world of geomatics its usefulness and functionality could be such as to affect the current procedure in various works, and not only in the representation, visualization and divulgation phases.

6. ACKNOWLEDGMENTS

The author would like express her great appreciation to Dr. José Manuel Valle Melón and Dr. Álvaro Rodríguez Miranda, the research supervisors, members of the Laboratory for the Geometric Documentation of Heritage (LDGP) of the University of the Basque Country (UPV-EHU), Spain, for the trust placed in her and her proposal, in addition to the enthusiasm and support shown right from the beginning.

CLGE students’ contest 2014 Sandra Uceda Queirós

7. BIBLIOGRAPHY

AZUMA, R.T. (1997). “A Survey of Augmented Reality” In Presence: Teleoperators and Virtual Environments 6 (4): 355-385. [http://www.cs.unc.edu/~azuma/ARpresence.pdf accessed May 2014]

BITTEL, J. (2013). “Archaeologists use virtual reality to explore long-gone worlds” [http://www.slate.com/articles/technology/future_tense/2013/09/virtual_and_augmented_realit y_in_archaeology_revive_pompeii_atalh_y_k.html accessed June 2014]

BOBRICH, J. & OTTO, S. (2002). “Augmented Maps”. Institute for Cartography and Geoinformatics, University of Hanover, Germany. In: Symposium on Geospatial Theory, Processing and Applications, Ottawa 2002. [http://www.isprs.org/proceedings/xxxiv/part4/pdfpapers/451.pdf accessed April 2014]

BRODESCHI, M., PATIÑO CAMBEIRO, F., GOICOECHEA CASTAÑO, I., PATIÑO BERBEITO, F.(A), PRIETO LÓPEZ, J.I. (B). (2011). “Augmented Reality: an innovative alternative for the collaborative design on construction´s projects” (A) Universidad de Vigo: Departamento de Diseño en la Ingeniería. (B) Universidad de Coruña: Departamento De Proyectos Arquitectónicos. In: Proceedings of the Improbé 2011. International conference on Innovative Methods in Product Design. Venice, Italy. [http://www.improve2011.it/Full_Paper/114.pdf accessed May 2014]

EGGERT, D., HÜCKER, D., VOLKER,P. (2014). “Augmented Reality Visualization of Archeological Data”. Institut für Kartographie und Geoinformatik, Leibniz Universität Hannover, Hanover, Germany. [http://www.ikg.uni- hannover.de/fileadmin/ikg/staff/publications/Begutachtete_Zeitschriftenartikel_und_Buchkapi tel/icc2013_eggert.pdf accessed June 2014]

FERNÁNDEZ ÁLVAREZ, A. J. (2010). ”De las arquitecturas virtuales a la realidad aumentada: un nuevo paradigma de visualización arquitectónica”. Departamento de Tecnología y Ciencia de la Representación Gráfica, Universidad de A Coruña. In: X Congreso Internacional Expresión Gráfica aplicada a la Edificación. APEGA 2010. [http://web.ua.es/es/x-apega-2010/documentos/id-118.pdf accessed June 2014]

KATO, H. & BILLINGHURST, M. (1999). ”Marker Tracking and HMD Calibration for a video- based Augmented Reality Conferencing System”. In: Proceedings of the 2nd International Workshop on Augmented Reality (IWAR 99). October, San Francisco, USA.

[http://www.hitl.washington.edu/artoolkit/papers/iwar99.kato.pdf accessed July 2014]

KOCH, C., NEGES, M., KÖNIG, M., ABRAMOVICI, M. (2014). “Performance Study on Natural Marker Detection for Augmented Reality Supported Facility Maintenance”. Ruhr Universität Bochum, Germany. In: Australasian Journal of Construction Economics and Building Conference Series.

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[http://epress.lib.uts.edu.au/journals/index.php/AJCEB-Conference-Series/article/view/3767 accessed June 2014]

LDGP (2004). “Documentación Geométrica de la Basílica de Armentia (Vitoria- Gasteiz, Álava)”. Laboratorio de Documentación Geométrica del Patrimonio (Universidad del País Vasco- Euskal Herriko Unibertsitatea UPV/EHU) –LDGP-. [https://addi.ehu.es/handle/10810/10380 accessed May 2014]

LDGP (2008). “Levantamiento fotogramétrico del yacimiento paleontológico “Museo in situ” de Ambrona (Soria)”. Laboratorio de Documentación Geométrica del Patrimonio (Universidad del País Vasco-Euskal Herriko Unibertsitatea UPV/EHU) –LDGP-. [https://addi.ehu.es/handle/10810/7353 accessed May 2014]

LDGP (2011). “Documentación Geométrica del dolmen del El Montecillo (Villabuena de Álava, Álava)”. Laboratorio de Documentación Geométrica del Patrimonio (Universidad del País Vasco-Euskal Herriko Unibertsitatea UPV/EHU) –LDGP-. [https://addi.ehu.es/handle/10810/10806 accessed May 2014]

MACKAY, W. E. (1998). “Augmented reality: linking real and virtual worlds. A new paradigm for interacting with computers.” Department of Computer Science. Université de Paris- Sud, France. [https://www.lri.fr/~mackay/pdffiles/AVI98.AugmentedReality.pdf accessed June 2014]

MARTÍN RAMALLAL, P.N. (2010-11). Tesina de Master. “Aproximación a la evolución de la interactividad e inmersión aplicado al discurso publicitario: desde el advergaming a la realidad aumentada”. Universidad de Sevilla. Máster en Comunicación y Cultura. [http://fama2.us.es/fco/tmaster/tmaster10.pdf accessed May 2014]

MECATE, E. V. T., GERHARDT, E. M. B., ABREU, M. V. S. (2011). “Realidade Aumentada aplicada à Visualizaçâo Cartográfica auxiliando o Mapeamento Participativo”. Universidade Federal De Viçosa- MG, Brasil. In: Simpósio Brasileiro de Sensoriamento Remoto, 15 (SBSR), 2302-2307. [http://marte.sid.inpe.br/col/dpi.inpe.br/marte/2011/07.15.12.34/doc/p1419.pdf accessed May 2014]

MILGRAM, P. & KISHINO, F. (1994) “A taxonomy of mixed reality visual displays” In: IEICE TRANSACTIONS on Information and Systems, 77 (12), 1321-1329. [http://etclab.mie.utoronto.ca/people/paul_dir/IEICE94/ieice.html accessed May 2014]

OH. Y.-J. & KIM. E.-K. (2014). “Efficient 3D Model Visualization System of Design Drawing Base

on Mobile Augmented Reality”. Department of Computer Engineering, Sunchon National University. Republic of Korea.

PORTALÉS RICART, C. (2008). Tesis Doctoral. “Entornos multimedia de realidad aumentada en el campo del arte”. Facultad de Bellas Artes de San Carlos. Departamento de Pintura. Universitat Politècnica de València. [http://riunet.upv.es/bitstream/handle/10251/3402/tesisUPV2829.pdf accessed May 2014]

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SIMONETTI IBAÑEZ, A. & PAREDES FIGUERAS, J. (2013). Tesina de Master. “Vuforia v1.5

SDK: Analysis and evaluation of capabilities”. Universitat Politécnica de Catalunya. [http://upcommons.upc.edu/pfc/bitstream/2099.1/17769/4/memoria.pdf accessed June 2014]

TORRES, D. R. (2013). Tesis Doctoral. “El papel de la realidad aumentada en el ámbito artístico- cultural: la virtualidad al servicio de la exhibición y la difusión”. Departamento Historia del Arte, Universidad de Granada. [http://hdl.handle.net/10481/30333 accessed May 2014]

VALLE MELÓN, J.M. (2007). Tesis Doctoral. “Documentación Geométrica del Patrimonio: Propuesta conceptual y metodológica”. Logroño, Junio de 2007. [http://hdl.handle.net/10810/7052 accessed June 2014]

WANG, X. TRUIJENS, M., HOU, L., WANG, Y., ZHOU, Y. (2014). “Interacting Augmented Reality with Building Information Modeling: Onsite construction process controlling for liquefied natural gas industry”. Curtin-Woodside Chair Professor for Oil Gas & LNG Construction and Project Management & Co-Director of Australasia Joint Research Centre for BIM, Curtin University, Australia. In: Automation in Construction 40. 96- 105. [http://dx.doi.org/10.1016/j.autcon.2013.12.003 accessed May 2014]

ZLATANOVA, S. (2002). Tesis Doctoral. “Augmented reality technology”. TU Delft. Section GIS technology, Faculty of Civil Engineering and Geosciences. Holanda. [http://www.gdmc.nl/zlatanova/thesis/html/refer/ps/GIST17.pdf accessed May 2014]

WEBSITES

AR-mediaTM. [http://www.armedia.it]

Trimble SketchUpTM. [http://www.sketchup.com/es]

The Metaio Creator. [http://www.metaio.com/creator/]

Qualcomm® VuforiaTM Developer Portal. [https://developer.vuforia.com]

Unity 3D. [http://unity3d.com/es]