Desenvolvimento de imagens 3D com o Google SketchUp para visualização no Google Earth®

Há poucos dias atrás entrei em contato com William Cartwright, Presidente da Associação Internacional de Cartografia,
para comunicar a criação do fórum e convidá-lo a postar e conhecer um pouco do meio cartográfico brasileiro.
Ele me respondeu com um email que continha um anexo relacionado a imagens 3D no SketchUp para visualizacao no
Google Earth.
É um artigo muito interessante, postarei aqui para que possamos compartilhá-lo entre nós cartógrafos:



Abstract

Since its launch in 2004, Google Earth has grown to become one of the most popular portals for spatial content on the web.
The intuitive and interactive nature of the application makes it ideal for use as a learning tool for students, particularly those in
the Spatial Sciences. As well as being a medium through which to deliver virtual field trips and media-rich presentations, Google Earth
also presents itself as a blank canvas onto which students can add and edit their own content. Keyhole Markup Language (KML), the
scripting behind Google Earth overlays and placemarks, is an easy language for students to learn and use, and can be introduced as
a follow up to HTML and XML training. With training, Geospatial Science students at RMIT have been able to create packages of information,
navigable in a similar way to which users navigate through Weplb pages. With both Google Earth and its associated 3D modelling software,
Google SketchUp, available for free download, students have been given the opportunity to create their own 3D content that can be uploaded
to the web and viewed remotely. Students are able to use the same software at home as they are at the University, providing opportunities to
develop online courses and, in turn, opening the creation of web based Geo-Visualization products up to a broader audience at university level.
This paper outlines how Google SketchUp has been used in a University context to develop 3D landscape visualisations and looks at the ways
in which Multimedia Cartography students are using Google Earth to visualise project data in ways not previously possible using traditional methods.


Introduction

The aim of a virtual world display is to provide realistic and truthful sensory cues about the real world by replaying stored information or by generating
information. Laurel (1995) has said that the important thing about VR is what it does rather than how its effects are achieved - it permits people to
behave as if they were somewhere they are not. VR transports users to some other place and enhances their perceptions about what they are experiencing
by appealing to several senses at once - sight, hearing and touch. These senses are stimulated by the sensations of force, resistance and texture and it
is predicted by Laurel that smell will eventually become available, and, that as virtual spaces begin taking on a richer, more complex texture, VR will be
the foundation of a major transformation in the ethos of computing. Laurel also sees artists using VR to represent the complexities of experience from
‘synthesthesia’ to emotional experiences, leading to a situation where: “VR may function as a link from the technological manifestations of humanity back
to the world that technology has ostensibly replaced” (Laurel, 1995, p. 70).
One of the key issues for building effective landscape visualizations concerns the sensory realism that is necessary in virtual world displays. How best to
facilitate this has demanded access to and the use of various tools and software packages. These were once expensive and, sometimes, difficult to use
without extensive training and practice. Now, commercial enterprises like Google actively engage users with their visualization software like Google Earth
and provide not just the application to deliver product, but also free, or relatively inexpensive software with which to develop content.


Digital earth and Digital Globes

In an address in 1998, then US Vice-President Al Gore (1998) said: “Now we have an insatiable hunger for knowledge. Yet a great deal of data remains
unused. … part of the problem has to do with the way information is displayed.” “The tools we have most commonly used to interact with data, such as
the “desktop metaphor” employed by the Macintosh and Windows operating systems, are not really suited to this new challenge. I believe we need a
“Digital Earth”. A multi-resolution, three-dimensional representation of the planet, into which we can embed vast quantities of geo-referenced data”.
“A Digital Earth could provide a mechanism for users to navigate and search for geospatial information - and for producers to publish it. The Digital
Earth would be composed of both the "user interface" - a browsable [sic], 3D version of the planet available at various levels of resolution, a rapidly
growing universe of networked geospatial information, and the mechanisms for integrating and displaying information from multiple sources”.
Al Gore’s address on the Digital Earth (Gore 1998) provided information about how this concept might be initially applied: …“In the first stage, we should
focus on integrating the data from multiple sources that we already have. We should also connect our leading children’s museums and science museums
to high-speed networks such as the Next Generation Internet so that children can explore our planet. University researchers would be encouraged to
partner with local schools and museums to enrich the Digital Earth project — possibly by concentrating on local geospatial information.” Gore’s idea
about using the metaphor of ‘Digital Earth’ is now being realised with readily-available products from both governmental and commercial enterprises.
‘Digital Globes’ are being employed to facilitate access to and visualization of geographical information.
According to Riedl (2007), there are three types of Digital Globes:
- Virtual hyperglobes: Visualization of the digital image on a virtual globe body in virtual space;
- Tactile hyperglobes (material hyperglobes): Visualization of the digital image on a physical (touch-sensitive) globe body in real space; and
- Hologlobes: Visualization of the digital image on a virtual globe body in real space.
It is the first type of Digital Globe that this paper focuses on – Virtual hyperglobes.
Products on the market include World Wind, an open-source product from NASA (worldwind.arc.nasa.gov), Virtual Earth from Microsoft (based on
Microsoft’s MapPoint technology) (virtualearth.msn.com) and Google Earth, the focus of this paper. The paper focuses particularly on how education
programs in cartography include elements that look particularly at Digital Globes and provide practical applications that allow students to explore the
potential that Digital Globes offer.


Virtual landscapes, digital globes and educational programs

Cartwright et al. (1998) addressed what should comprise a contemporary programme in cartography. They saw that a programme should have at its
core a number of key courses that provided ‘overview’ content – the ‘Holistic Thinking’ elements that were built around foundation knowledge and
professional aspects. To this were added courses in management, location and positioning, ‘production’ aspects of quality, data acquisition,
management and planning, presentational techniques and theory and practice relating to the implementation of mapping programmes. The aspect
discussed in this paper focuses on the practical elements of a contemporary program – the Multimedia Cartography program at RMIT – and how
students undertake the development of contemporary landscape visualizations
The Multimedia Cartography program in the School of Mathematical and Geospatial Sciences at RMIT University has, over the last 5-10 years, seen
students learning and experimenting with Virtual Reality Modelling Language (VRML). Studying the basics of VRML has given students an introduction
to the possibilities of 3D Geographical Visualisation. Whilst VRML did give students a solid introduction to the concept of modelling in three dimensional
space, the ‘hard coding’ nature of the practical exercises resulted in students investing a lot of time into models that, whilst fulfilling the submission
requirements fully, were often not as impressive or detailed as the students had hoped to produce.

Throughout their studies, students were exposed to comprehensive, near-photo realistic examples of VRML created by research teams at RMIT.
Inspired by such models, students often proposed to include visualisations with a similar level of realism into their major projects. A typical project
is that completed by former student Dane McGreevy (Figure 1). Upon recognising the time involved in creating models with such high levels of detail,
these students often felt discouraged to continue with the 3D component of their product, or were resigned to the fact that, in order to complete all
the components of their project on time, they would need to focus on building a much simpler VRML model.





In 2000, @Last Software launched a 3D modelling application called SketchUp. Primarily designed for the architectural industry, the program developed
through several iterations, gaining a strong following of professionals and students in the construction, landscape design, urban planning, game
development and product design fields. Unlike other 3D modelling software, SketchUp uses a patented (Google Sketch-up, 2003) metaphor of creating
a flat, 2D shape and ‘pushing’ or ‘pulling’ it into the third dimension to create 3D objects (see Figure 2). This concept was designed to make SketchUp
far more intuitive than traditional 3D Computer Aided Design applications and to encourage users to experiment more with their designs, toying with
‘what if’ scenarios with much more freedom.





In March of 2006, the company was acquired by Google and a free version, Google SketchUp, with slightly limited functionality, was released to the
public for download. The software was designed to interact directly with Google Earth, allowing users to create their own geographically referenced
3D models, that they can then share with others via the Google Earth Community (Google Earth, 2007).



SketchUp in the classroom

With the developments in 3D landscape visualisation being so highly publicised in our industry and beyond, giving Multimedia Cartography students
the opportunity to create detailed 3D content is something that is considered of quite high importance. One of the major advantages of the VRML
scripting language, over traditional modelling software packages, was the fact that students could work on their projects outside of class time, as
the only software required to write the code is a text editor, such as Notepad. The VRML plug-in is also available for free, meaning students can
work at home without having to purchase expensive software.
Shortly after Google’s acquisition of SketchUp and the release of the free version, several students proposed using the software as part of their major
projects. Uses included detailed modelling of geographic terrain features, representations of land development proposals and the placement of 3D
‘signposts’ and graphic objects in Google Earth (See Figure 3).




With Google Earth becoming such a widely used application, both in our industry and beyond, it was decided that the software should become
an official part of the program curriculum. After being invited to contribute to the 2007 National Youth Science Forum (2007) program in February ,
it was decided that this would be an ideal opportunity to implement an amended version of the Google SketchUp practical exercises being developed.
Year 11 students participating in the program were guided through the fundamentals of the application and then asked to build a 3D model of
their house, or another building they knew well, before exporting the finished product into Google Earth. Watching the enthusiastic and excited
reactions of these non-geospatial students gave some indication that such exercises would be extremely beneficial to, and be well received by, our own students.
In the weeks since, Google SketchUp and KML (Keyhole Markup Language) practical exercises have been introduced into several Multimedia
Cartography courses. Students have participated well and are showing high levels of experimentation with both the software and scripting language.
Students in their second and third years of the program have used KML to construct self-contained packages of information for display in Google Earth.
These packages have contained individual placemarks, containing location information, descriptions, photos, 360 degree panoramic images and links to
external information; lines and polygons showing various geographic features along with their own image overlays. Students have been encouraged to
customise their KML projects by creating customised icons and placemark styles to reflect the theme of their projects (See Figure 4). Many students have
then created landmark buildings and detailed signposts in SketchUp and added these to their projects, before exporting all the elements as one KMZ file.
A number of third year students have taken the extra step of incorporating these KMZ information packages into their major multimedia projects
(primarily built in Flash), recognising the highly distributable nature of the file format (as opposed to an authored multimedia DVD product, for example).




Whilst agreeing that the KMZ files cannot convey all the information contained in their full major projects, the students said that, with such simple,
straightforward creation and editing it made sense to include the files in their project, as it is one of the easiest ways to geographically link their work to
such a complete, worldwide dataset.


Conclusion

Although the SketchUp and KML practicals, as described, have only recently been introduced into the curriculum, the reception by students has been
extremely positive. The ability to create customised, geographically referenced data for such a globally accessible medium has been embraced by
students, as they incorporate data from their own research projects into the mass of information already available on Google Earth. In an effort to
raise awareness of the geospatial sciences at RMIT, plans are being discussed to introduce a general elective subject, open to all students in the
university, focussing on the production of KML placemarks and associated 3D content to be viewed and assessed using Google Earth. With the application
seemingly as popular with those outside the geospatial sciences as it is with those working in the industry, exposing RMIT Multimedia Cartography
students to the possibilities of the application is a vital step in preparing them for the advances in web based Geo-Visualization they may encounter
upon entering the professional world.


References

Cartwright, W.E., Fraser,D., Ormeling,F. and Pupedis, G, 1998, "Hypereducation:W E, Fraser, D, Gore, A., 1998, The Digital Earth: Understanding
our planet in the 21st Century, Speech given at the California Science Center, Los Angeles, California, January 31, http://www.digitalearth.gov/VP19980131.html
Google Earth, 2007, Google Earth Community. http://bbs.keyhole.com/entrance.php?Cat=0.
Google Sketch-up, 2003, @Last Software Awarded Patent for SketchUp Software Program. http://www.sketchup.com/?id=4&recordid=18.
National Youth Science Forum, 2007, National Youth Science Forum Home page. http://www.nysf.edu.au/.
Ormeling, F and Pupedis, G (1998) Hypereducation: prospects for delivering region-wide cartographic science courses on the Web
",Web. Cartography, vol.27, no.2, pp. 27-40.
Laurel, B., 1995, “Virtual Reality”, Scientific American, September, p. 70.
Riedl, A.., 2007, "Digital Globes", Multimedia Cartography Edition 2, Cartwright, W. E., Peterson, M. P. and Gartner, G.(eds), Heidelberg: Springer-Verlag, pp. 255 – 266.