Virtual Campus

Alexei Sourin,
Nanyang Technological University, Singapore
assourin@ntu.edu.sg

---

Contents

• 1. NTU story

• 2. Now you can fly

• 3. Shared Virtual World

• 4. Collaborative Shape Modeling

•  5. Where do we go tomorrow?

• References

---

Abstracts: Virtual Campus is a shared virtual model of Nanyang Technological University. It is a great place for electronic education and fun, research and games, meeting new friends, and immersion in campus life. It can be accessed from any Internet connected computer running MS Windows. In this place you can be anything: choose a fancy look, or turn yourself into a sports car, spooky creature, insect, or sparkling cloud. Everything is possible in this cyberworld. You may wander around or fly, go to offices or student hostels, attend electronic lectures, or just chat with other visitors or robots. One of the places of the Virtual Campus is Collaborative Shape Modeling Hands-On Experience. Being a part of the computer graphics course, it teaches students how 3D shapes and their colors can be easily defined with parametric and implicit functions.

Key words: VRML, shared virtual worlds, electronic education, shape modeling.

 

1. NTU Story

"Nanyang" in Chinese means "south of the ocean" or "south seas"—a reference to the Southeast Asian region. Back in the 1940s and 50s, many Chinese from mainland China ventured south to seek their fortunes in new lands. Malaya—Singapore and Malaysia—was then known as "Nanyang" to the Chinese. After World War II, it was decided to start a university in Singapore, a university that would provide tertiary education in Chinese in the region. On 23 March 1953, 523 acres of land was donated to the new Nanyang University, which was affectionately known as "Nan Tah" in Chinese. The modern Nanyang Technological University (NTU) [1], which originated from Nanyang University, also adopted the name "Nan Tah" for its Chinese name in the mid 1990s. It occupies a large beautiful Jurong Campus with very hilly terrain, located in the western part of Singapore. The campus has many buildings with quite sophisticated futuristic architecture, some of them designed by the famous Japanese architect Kenzo Tange (Figure 1).

Fig. 1. Nanyang Technological University

 

2. Now you can fly

Can students fly? Can they touch the sky? They certainly can in the Virtual Campus of NTU.

The idea to build a virtual reality model of the NTU campus came about six years ago when we purchased a powerful SGI Onyx RE² graphics workstation with advanced modeling software systems MultiGen and Vega [2]. There was also a very impressive demo of Performer Town [3]—a small virtual town surrounded by mountains (Figure 2).

 

Fig. 2. Performer Town modeled by Wes Hoffman of Paradigm Simulation
using the MultiGen database modeling tool and explored using Perfly.

 

This Performer Town inspired us to think about making our very own virtual campus. But we had only tools, no methods and solutions. On top of this, the very hilly ground of the campus complicated the task very much. No existing virtual reality projects dealt with anything like this. We had to be first and we wanted to make an accurate model with a precision of about 0.3 m. Upon examining the available resources, we decided to make the virtual land based on information extracted from contour maps. Roads, lampposts, trees, and traffic signs were measured by computer engineering students who had to turn themselves into surveyors. Next came geometric modeling. Roads, created first, hung in the void before adjoining pieces of land were attached to them one by one. The author personally checked each road by “jogging” around the virtual land. The next steps were planting all those gorgeous tropical trees and bushes, inserting lampposts and signs, and, finally, constructing the buildings. Projecting the geometric complexity of the buildings in a photo-realistic way required a lot of time and imagination as well as experience in photography and interactive graphics modeling. Many digital photos were taken and converted to texture images. The author even had to climb to the roof of one of the tallest building to take a panoramic shot of the surrounding area to turn it onto a backdrop image.

Finally, it was done: we made a digital copy of the real campus stored in the computer. Just for fun, we put it in a virtual “water globe” (Figure 3). We could shake it, we could turn it over, and of course we could go inside it to the virtual campus, and there we could walk, drive and even fly!

 

Fig. 3. Virtual campus … which is kept in a water globe.

 

It was a lot of fun. It was shown to many VIP visitors and featured on television. But only a very special computer could be used for running the virtual campus.

 

3. Shared Virtual World

3D web visualization developed rapidly. Personal computers became capable of making VR walk-through even in shared virtual worlds. Cybertown [4], built with Virtual Reality Modeling Language (VRML) [5] under Blaxxun Platform [6], inspired us to putting the Virtual Campus on the web. It was not a straightforward solution since a lot of polygon reductions had to be made to find a compromise between realism and the size of the model. We also had to build many new models since the real campus of NTU is always changing. The whole model had to be designed in such a way that it would allow for a smooth walk-through in any part of the campus despite the polygonal complexity. It was achieved by careful spatial organization with a hierarchy of bounding boxes, as well as by using level-of-detail, view distance and other technical tricks used in VRML worlds. Eventually it was completed and published on the web. The whole campus including textures is now stored in about 8 Mb of files and can be accessed from any Internet connected personal computer [7]. Once you enter this world, you can turn yourself into virtually anything—from a human-like avatar to something really weird. Some visitors choose to look like fancy-dressed people, some turn themselves into sports cars, and some appear as sparkling clouds or fire-balls (Figure 4).

 

Fig. 4. Scenes of the Virtual Campus.

 

Many visitors are computer graphics students, who either play virtual “hide-and-seek” with their professor or come to study concepts of virtual reality and shape modeling. There are also virtual strangers from around the world. The place is usually crowded around 4pm GMT, with Singaporeans, French, Germans, Italians, and others meeting together on this hospitable land. While local students easily navigate the familiar 3D environment, the foreign guests usually just wander around and chat, astonished by the size of what is probably the biggest shared world of this kind. Yes, there, you can fly like a bird and walk through walls. You can even safely jump from the roof of Nanyang Heights! However, never attempt to do this after returning to the real world. The author remembers a funny feeling how after several hours of flying in the virtual campus, he tried to “take off and fly” on his way back home from the lab.

Virtual Campus is not only for walking-through and seeing other avatars or robots. You can talk to them! Blaxxun Contact provides the communication platform for it. It even allows for text-to-voice synthesis so that you can hear your computer-simulated voice as well as voices of other visitors. These chats may involve all the visitors or can be organized into private chat groups (Figure 5).

 

Figure 5. It is night in Singapore but not too late for chatting in the Virtual Campus.

 

Virtual Campus is a place of research on crowd simulation and shared cyberspaces. Sometimes you meet an avatar who is in fact a robot, and it will take time before you understand it. Sometimes it may be otherwise.

 

4. Collaborative Shape Modeling

Cyber-learning is one of the applications of the Virtual Campus. NTU professors are able to meet with their students in virtual classrooms, while distant students will get a feeling of really being on the campus. Some of the virtual lecture theatres and other places are linked to streaming multimedia presentations of current and prerecorded lectures and events through the NTU’s e-learning framework edveNTUre [8] (Figure 6).

 

Fig. 6. Streaming media as a part of e-learning in NTU: Lecture on OpenGL.

 

Of course Virtual Campus is a learning tool for computer graphics students illustrating to them theoretical concepts of virtual reality, real time rendering and shape modeling. It is used during lectures, as well as after classes for consultations. It is fun and educational. One of such activities is the Collaborative Shape Modeling Hands-On Experience. The virtual class-room where this virtual lesson is running can be entered both from the Virtual Campus as well as by a direct link [9].

Upon arrival in the virtual class-room, new visitors will be advised to install a small software plug-in, which can be done on the spot. This plug-in is an extension of VRML which allows for defining shapes with analytical formulas. By “formulas” we understand analytical definitions with parametric, implicit and so-called F-Rep formulas, which are explicit functions of three coordinates. In our model, these very different analytical representations can be used concurrently for defining the geometry and appearance of shapes. The theoretical foundations and details of this approach can be found in two project web pages on Function-based Web Visualization [10], and Interactive Function-based Shape Modeling [11].

After the plug-in is installed, besides the regular VRML objects, function-defined shapes will become visible as well. There will be one big shape hovering in the middle of the room, as well as a few smaller fancy shapes displayed in different parts of the room. The big shape is the one, which the visitors interactively create. The smaller function-defined shapes are examples of the best works created in the previous sessions. Participants of the collaborative shape modeling class may discuss the design in the chat box of the browser, type individual shape modeling commands or command scripts in there, and immediately see how the shape changes (Figure 7a). The geometry, color and 3D texture of the shape can be interactively defined with analytical formulas written in C-style syntax. A large library of standard mathematical functions can be used in the formulas. For implicit and F-Rep functions, two set-theoretic operations—union and intersection—are provided for making complex constructive solid geometry shapes. The function-based VRML description of the current shape can be displayed at any time and saved for future use (Figure 7b). The same parametric, implicit or F-Rep formulas can be re-used with little modification for defining both the shapes and their appearances thus illustrating the concepts of shape modeling. Since each shape is in fact defined by only two analytical formulas—one for geometry and one for appearance—these formulas can easily be edited and exchanged when building other cyberworlds (Figure 8).

 

(a)

(b)

Fig. 7. Collaborative Shape Modeling Hand-On Experience in the Virtual Campus of NTU

 

 

Fig. 8. VRML code of the function-defined water-melon.

 

5. Where do we go tomorrow?

The construction of the Virtual Campus never ends, just as it never ends on the real campus. You never know what you’ll find there tomorrow. Since the size of the model cannot be increased above a certain level currently acceptable for web visualization, Virtual Campus is expanding non-linearly. It is in fact a meta-world, which consists of many smaller “parallel” shared virtual worlds. Each university school and student hall of residence has its own model and respective communication space. When you enter or leave these worlds, it looks like you are still in the same virtual environment, however these smaller worlds are different cyberspaces. We are working on further expansion of the model to the surrounding areas and eventually to the whole of Singapore.

 

References

[1] NTU web-site http://www.ntu.edu.sg

[2] MultiGen-Paradigm http://www.multigen.com/

[3] Performer Town: Visual Simulation scene http://www.sgi.com/software/performer/gallery.html

[4] Cybertown http://www.cybertown.com

[5] VRML specification http://www.web3d.org/x3d/specifications/vrml/ISO_IEC_14772-All

[6] Blaxxun Contact http://www.blaxxun.com

[7] Virtual Campus of NTU http://www.ntu.edu.sg/home/assourin/vircampus.html

[8] EdveNTUre http://edventure.ntu.edu.sg

[9] Collaborative Shape Modeling http://www.ntu.edu.sg/home/assourin/vircampus/vircampus/fshapelab/contact_fshapelab.htm

[10] Function-based Web Visualization http://www.ntu.edu.sg/home/assourin/FVRML.htm

[11] Interactive Function-based Shape Modeling http://www.ntu.edu.sg/home/assourin/Intshape.html