VIRTUAL REALITY TECHNOLOGY IN MUSEUMS: AN IMMERSIVE EXHIBIT IN

THE “MUSEO LEONARDIANO”

Paolo Fiamma a and Nicoletta Adamo-Villani b a Department of Civil Engineering, University of Pisa, Pisa, Italy - paolo.fiamma@ing.unipi.it

b Department of Computer Graphics Technology, Purdue University, West Lafayette, IN USA -

nadamovi@purdue.edu

KEY WORDS: Virtual Reality, 3D animation, VR museum exhibits, Leonardo da Vinci

ABSTRACT:

In this paper we describe the design and development of an interactive, immersive installation created for the Museo Leonardiano

(Leonardo’s museum) in Vinci, Italy. The exhibit was part of a series of events aimed at celebrating Leonardo da Vinci’s Genius

and its specific purpose was to let the viewers visualize and experience Leonardo’s visionary concept of an infinite, heliocentric

universe (anticipatory of the Copernican System) as opposed to Ptolemy’s model of a finite, geocentric world. The viewers were

first immersed in a 3D synthesized geocentric universe and taken through a virtual journey across the eight spheres of Ptolemy’s

cosmological model. Then they travelled through Leonardo’s heliocentric world and explored it from unique points of view. In the

first journey the visitors perceived the cosmos as a closed, static entity, whereas in the second voyage they experienced Leonardo’s

revolutionary concept of an open, dynamic universe part of an infinite space. The interactive exhibit was based on the use of Virtual

Reality (VR) and 3D Animation technologies. The hardware setup consisted of a single-screen portable immersive system with head

and hand tracking technology and passive stereo. The visual content included 3D renderings of Ptolemy’s and Leonardo’s universes

designed, modeled and animated by the authors in Autodesk Maya software. The audience reactions and comments demonstrated the

effectiveness of the technology for visualizing the two systems and for conveying the contrast between the two cosmological

models. The project described in the paper had two higher objectives. The first goal was to investigate the potential of VR

technology as an educational/entertainment tool and as an instrument of historic research, simulation, reconstruction and

dissemination in museums. The second objective was to initiate research toward the design of a novel museum space and

technological infrastructure to support the development and display of VR immersive exhibits in the Da Vinci museum.

1. INTRODUCTION

In this paper we describe the design and development of an

interactive exhibit created for the Museum Leonardo da Vinci

in Vinci, Italy. The exhibit was part of a series of events called

“Celebrazioni Leonardiane” (May 2008 - July 2008) that took

place in various locations in Leonardo’s home town. The events

included cultural, scientific, educational, artistic, and

entertainment activities which aimed at celebrating Leonardo’s

visionary ideas in a variety of fields spanning engineering,

science, art, anatomy, mathematics, and astronomy. The

emphasis of the “Celebrazioni Leonardiane” was on the

dissemination of many aspects of Leonardo’s work that are still

under study and exploration and, therefore, not fully known to

the general public. The specific objective of the exhibit

described in the paper was to visualize Leonardo’s intuition of a

heliocentric, infinite universe in opposition to Ptolemy’s theory

of a geocentric system.

The interactive installation made use of 3D animation and VR

technologies because of their advantages over traditional media

and 2D multimedia. VR-based museum exhibits have gained

popularity in recent years and a few examples have been

reported in the literature (Hirose, 2007) (Roussou, 1999).

Researchers argue that VR installations offer several benefits

over more traditional museum exhibitions (Roussou, 2007)

(Youngblut, 1997). These advantages, discussed in detail in

section 3, include: a more effective way of communicating the

scientific results of historical investigations through

photorealistic reconstructions of places and people that no

longer exist or may not be easily experienced; intuitive visual

representation of abstract concepts, systems and theories that

would be difficult to communicate with diagrams, textual

descriptions and static images; and enhanced viewer’s

engagement and motivation through high level of interactivity

and “immersion”. Immersion is defined as “the illusion of being

in the projected world.. surrounded by images and sound in a

way which makes the participants believe that they are really

there” (Roussou, 2001).

These reported strengths have motivated the choice of VR

technology as the base for our exhibit which is the first example

of VR installation in the museo Leonardiano. The visitors’

comments have confirmed the effectiveness of VR and 3D

animation technologies for communicating Leonardo’s vision.

The full paper is organized as follows: In section 2 we describe

Leonardo’s visionary concept of a heliocentric infinite universe.

In section 3 we give an overview of virtual reality technology,

we report examples of VR museum exhibitions, and we discuss

the potential of VR as a tool for research, visualization and

education in informal settings. Detailed descriptions of the

installation including the immersive system, the animated

models, the architectural setting, and the viewer’s interaction

experience are presented in section 4. Discussion and

conclusive remarks are included in section 5.

2. LEONARDO’S UNIVERSE

Ptolemy’s geocentric model of the universe was the accepted

cosmological system during Leonardo’s times. It was based on

the theory that the earth is at the center of the universe and the

sun and other objects go around it. Belief in this system was

common in ancient Greece and was embraced by many

medieval astronomers and philosophers. In the first book of the

Almagest (Encyclopedia Britannica, 1952), Ptolemy described

his geocentric model and gave various arguments to prove that,

in its position at the center of the universe, the spherical earth

must be immovable. Ptolemy’s system consisted of a series of

concentric spheres containing the celestial objects positioned in

the following order: earth, moon, mercury, venus, sun, mars,

jupiter, and saturn. The heavenly bodies moved along deferents,

large circles centered on the earth, and epicycles, small circles

whose centers moved around the deferents. The sun, moon and

planets moved along the circumference of their own epicycles;

the universe ended in the sphere of the “fixed stars”. Beyond

were two crystalline spheres and an outer sphere named the

“primum mobile” or first motion, which was circumscribed by

the “coelum empyreum”, of a cubic shape, wherein happy souls

found their abode (Polaris Project,

http://www.polaris.iastate.edu/EveningStar/Unit2/unit2_sub1.ht

m). Ptolemy’s theory, which was able to justify the presence of

the celestial bodies and their apparent motion around the earth,

resulted in the conception of a finite, limited universe defined

by a very rigid sequence of concentric vaults.

Leonardo was interested in astronomy and anticipated several

fundamental concepts which are reported in: “Studies on the

dimensions of the Earth and Moon in relation to the Sun” (see

figure 1), in his drawings of the moon, in “Notes on the

illumination of the moon”, and in his studies on the heat of the

sun and scintillation of the stars (Leonardo da Vinci, Codex

Hammer). Of all his intuitions, the most revolutionary was the

one related to the centrality of the sun. While Leonardo’s early

reflections of 1482-1500, contained in the Codex Atlanticus

(Leonardo da Vinci, Codex Atlanticus), Arundel (Leonardo da

Vinci, Codex Arundel), Hammer (Leonardo da Vinci, Codex

Hammer), and F (Leonardo da Vinci, Codex F) show adherence

to Ptolemy’s theory: “il Sole che scalda tanto mondo quant’è

vede, e che in 24 ore fa si gran corso” (Codex Atlanticus, f.

30v), his later writings demonstrate his rejection of the

geocentric system: “Come la Terra non è nel mezzo del cerchio

del Sole, né nel mezzo del mondo, ma è ben nel mezzo de” suoi

elementi, compagni e uniti con lei, e chi stesse nella Luna,

quand”ella insieme col Sole è sotto a noi, questa nostra Terra

coll”elemento dell”acqua parrebbe e farebbe ofizio tal qual fa

la Luna a noi” (Codex F, f. 41v) (Calanca, 2007).

Fig 1: Leonardo’s drawing: “Annotazioni non organiche sulla

Terra e sulla Luna, con particolare riferimento alla loro

dimensione ed al rapporto col Sole” (Leonardo da Vinci, Codex

Hammer)

Leonardo realized that the earth is a planet which reflects light,

moves around its own axis, and is subject to a continuous cycle

of geological transformations. Further, in the W.L. manuscript

(f. 132r) (Calanca, 2007) Leonardo wrote: “El sol no si move”

(the sun does not move). These words and other observations

contained in the same manuscript lead to think that Leonardo

elaborated an early heliocentric theory several decades before

Nicolaus Copernicus wrote the De Revolutionibus (Copernicus,

1543). Although Leonardo did not possess any scientific

instrumentation able to plumb the depths of the skies and

therefore prove his intuitions, he believed in the possible

existence of a cosmological model in which the earth was not

an immobile entity at the center of the universe.

Leonardo’s intuition is of enormous importance and

significance, especially if we consider the historical context in

which it was formulated. The need not only to document and

visualize Leonardo’s vision, but also to convey the sharp

contrast between the conception of a finite geocentric world and

the vision of a heliocentric infinite space are the main reasons

for the realization of the exhibit described in the paper.

3. VR TECHNOLOGY IN MUSEUMS

VR is a technology that allows users to explore and manipulate

computer-generated, three dimensional, interactive

environments in real time (Sherman, 2003). VR is based on the

theory that people do not experience reality directly, they

receive a series of external stimuli which are interpreted by the

brain as reality. “If a computer application can send the same

external stimuli that the brain can interpret, then the simulated

reality is potentially undistinguishable from reality” (Akins,

1992). Two types of VR environments exist: desktop and total

immersion. The installation described in the paper is an

example of immersive, interactive VR environment. Immersive

VR applications are usually presented on single or multiple,

room-size screens, or through a stereoscopic head-mounted

display unit. The user interacts with the 3D environment with

specialized equipment such as a data glove, a wand or a 3D

mouse. Sensors on the head unit and/or data glove track the

user’s movements/gestures and provide feedback that is used to

revise the display, thus enabling smooth, real time interactivity.

The use of immersive VR technology is a relatively recent trend

originally limited to academic, military, and industrial research

and development centers. Until recently, the high cost of VR

displays and interaction devices coupled with difficulties in

usability, operation and system maintenance have posed major

barriers to the widespread use of the technology in schools and

public spaces such as museums and cultural centers.

Nevertheless, as the technology matures, VR applications are

entering multidisciplinary areas such as education, art, history,

and the humanities in general. Youngblut reports over forty

VR-based learning applications (Youngblut, 1997) and Roussou

describes about ten Virtual Environments designed for informal

settings (Roussou, 2006).

As representative institutions involved in research and

presentation of a variety of disciplines, museums are in an ideal

position to make use of VR technology in order to “investigate

its research, educational and entertainment potential while

effectively shaping how it can be used to deliver education and

recreation to the broad public” (Roussou, 2001).

To date, a few VR-based exhibitions have been produced in

museums worldwide. The first exhibit that made use of VR

technology is “The Virtual Ancient Egypt” installation funded

by Intel’s Design Education and Arts (IDEA) program. The

application presented users with a virtual recreation of the

Temple of Horus, constructed at Edfu during the New Kingdom

era in ancient Egypt. It was exhibited in networked form at the

Guggenheim Museum in New York and at the Machine Culture

exhibit of SIGGRAPH ‘93 (Interacting with “Machine Culture”,

1993).

Another early example is the “Virtual Endeavour” exhibit held

at the Natural History Museum in London, UK in 1997. The

installation included a 3D digital replica of Captain Cook’s HM

Bark Endeavour (The Natural History Museum,

http://www.nhm.ac.uk/ ).

More recent applications are the immersive installations at the

Foundation of the Hellenic World (FHW) in Greece (Roussou,

2000) (Gaitatzes, 2000). The VR exhibit “A Journey through

Ancient Miletus” allows participants to walk or fly over an

accurate 3D reconstruction of the city of Miletus, experience

the life of its people, examine architectural details from

different perspectives, and get an understanding of the sense of

scale, proportion and space used by the ancient Greeks.

Another VR-based exhibition is the “Mayan Civilization” held

at the National Science Museum in Tokyo in 2003 (Hirose,

2006). The exhibit included a VR theater with a 4mx14m

curved screen onto which 3 Hi-Vision equivalent images were

projected, and a large-capacity graphics workstation utilized for

image generation. The exhibit propelled the visitors on an

immersive voyage of discovery through a virtually synthesized

Copan acropolis.

In addition to the fact that VR technology is becoming more

affordable, VR exhibits are gaining popularity primarily

because they offer three main advantages over traditional

museum exhibits: (a) representational fidelity; (b) immediacy of

control and high level of active user participation; and (c)

presence (Hedberg, 1994).

(a) Representational fidelity refers to the degree of realism of

the rendered 3D objects and the degree of realism provided by

temporal changes to these objects. (b) User control and high

level of participation refer to the ability to look at objects from

different points of view, giving the impression of smooth

movement through the environment, and the ability to pick up,

examine and modify objects within the virtual world (Dalgarno,

2002). (c) The feeling of presence, or immersion, occurs as a

consequence of realism of representation and high degree of

user control. It makes the VR exhibit intrinsically motivating

and engaging by giving the users the illusion of really being

part of the reconstructed world, and by allowing them to focus

entirely on the task at hand. In addition, several studies have

shown that immersive VR applications can provide effective

tools for learning in both formal and informal settings

(Youngblut, 1997) (Roussou, 2007) (NCAC, 2003).

Because of this unique set of characteristics, we have focused

on Virtual Reality as the technology of choice for the exhibit

described in the paper.

4. THE IMMERSIVE EXHIBIT

4.1 The visual content

The visual content included 3D animated models of the

geocentric and heliocentric systems. Both systems were

modeled textured and animated in Maya 8.5 software (Autodesk

Maya, http://www.autodesk.com). The Ptolemaic model

consisted of eight polygonal spheres (the earth and seven

planets), eight semi-transparent, concentric hemispheres, and a

3D avatar standing on top of the earth. The hemispheres

represented the vaults enclosing the planets and the “sky of the

fixed stars”. The avatar’s eyes defined the position of the point

of view for the beginning of the virtual journey. Leonardo’s

universe included ten spheres (eight planets, the sun, and the

moon) and one scaled-up hemisphere which symbolized the

infinite galaxy. The Ptolemaic system is shown in figures 2-3;

Leonardo’s heliocentric model is shown in figure 5.

Figure 2: 3D renderings of Ptolemy’s universe

Figure 3: 3D renderings of close-up views of planets (left) and

Earth with avatar (right), both from Ptolemy’s universe

Figure 4: Reference images used to model Ptolemy’s universe:

illustrations from Andreas Cellarius Harmonia Macrocosmica,

(left and middle), and from the Christian Aristotelian cosmos

(right)

In order to maintain high speed of response in a real-time

immersive environment, the polygon count of each model was

kept fairly low (e.g. <30,000 polygons per universe). To realize

high visual quality with a limited number of polygons, surface

details were added by the use of a variety of colour,

transparency and bump textures painted by the authors and

applied to the surfaces as projection and parameterized maps.

The textures of the Ptolemaic system were based on images

from Andreas Cellarius Harmonia Macrocosmica, 1660/61

(Van Gent, 2003) and from the Christian Aristotelian cosmos,

engraving from Peter Apian’s Cosmographia, 1524 (Britannica

online, http://www.britannica.com/ ). Three of the reference

images are shown in figure 4. The textures of the planets in the

heliocentric system were created in Maya Paint Effects with

reference to NASA images (NASA,

http://pds.jpl.nasa.gov/planets/ ), while the surface of the

moon is based on Leonardo’s “Notes and drawings relating to

the Moon” and on “Studies of the Illumination of the Moon”

(Leonardo da Vinci, Codex Hammer). A rendering of the 3D

model of the moon and Leonardo’s drawing are shown in figure

6.

Figure 5: 3D rendering of Leonardo’s heliocentric system

(top); wireframe model showing the polygonal meshes and

animation paths (bottom)

Figure 6: 3D rendering of Leonardo’s moon (left), Leonardo’s

drawing of the moon (right)

The lighting setup of Ptolemy’s model included two directional

lights with 0.5 intensity; Leonardo’s system was illuminated by

one directional light with 0.4 intensity and one omni light

(positioned in the center of the sun) with 1.0 intensity and glow

effect. All planets were animated using motion path animation:

the spheres were attached to circular paths in the geocentric

system, and to elliptical curves in the heliocentric model.

Camera motion was controlled in real time by the participant

during the interactive journey.

The animated models were exported from Maya to VRML

format and imported in Vizard 3.0 software (WorldViz,

http://www.worldviz.com/products/vizard/index.html). Vizard

is a 3D development interface that supports real-time rendering

and interaction in the VR immersive environment as well as

communication with the visualization display and tracking

devices.

Images and videos of the models are available at:

http://www2.tech.purdue.edu/cgt/i3/da%20vinci/leonardo.htm

4.2 The immersive system

The VR system consisted of a screen and frame, a high-end

laptop, two commodity projectors, a pair of polarizing filters,

and passive polarized glasses. Despite the very limited size of

the room, the use of back projection allowed the audience to

enjoy a usable space of 3x4x2.5m in front of the screen.

Interaction was limited to navigation through the environments

and was controlled remotely or by the participant. When

controlled remotely, the user point of view was based on the

position of the eyes of an imaginary viewer located

approximately in the center of the group of visitors. Figure 7,

left, shows a visitor travelling through the geocentric model.

Figure 7: Participant interacting with the exhibit (left); Torre

della Rocca dei Conti Guidi (right). The arrow points to the

location of the installation

4.3 The architectural space

We chose to locate the VR exhibit in the “Hall of the Platonic

Solids”, the highest room of the museum on the top floor of the

“Tower of the Rocca dei Conti Guidi” (see figure 7, right). The

choice of the spatial setting contributed to further emphasize the

innovative and unique nature of the installation. Although the

room is located in the heart of the museum itinerary, it is, at the

same time, an independent and unique space with distinctive

features that set it apart from the other museum rooms.

The room can be accessed through a steep staircase which

immerses the visitors in a typical medieval setting, thus helping

them assimilate the historical context in which Leonardo

conceived his visionary ideas. The architectural space appears

pure and essential, defined by the walls of the tower, on three

sides, by the “sky of the wooden platonic solids”, and

completely open on the entrance side. The environment has no

predefined directionality and is designed as an “absent,

invisible” space seamlessly and unobtrusively combined with

the exhibit itself. No major changes to the room lighting

conditions, temperature, and accessibility were implemented.

Although just a first experimentation, the VR exhibit and the

design of its spatial setting have allowed us to identify specific

architectural and technical requirements (i.e. optimum spatial

layout, lighting conditions, temperature, security, accessibility,

maximum capacity) which will guide the design of a new

museum environment for technology-based exhibits.

4.4 The viewer’s experience

The purpose of the installation was to let the viewers visualize

and experience Leonardo’s visionary concept of an infinite,

heliocentric universe (anticipatory of the Copernican System)

as opposed to Ptolemy’s model of a finite, geocentric world.

The viewers were first immersed in the geocentric universe and

taken through a virtual journey across the eight spheres of

Ptolemy’s cosmological model. Then they travelled through

Leonardo’s infinite universe and explored it from unique points

of view. The first journey allowed the visitors to experience the

cosmos as a closed, static entity. The viewers navigated

through a sequence of concentric hemispheric vaults

(represented as semi-transparent shells) which enclosed

perfectly spherical vitreous planets. The journey ended in the

“vault of the fixed stars” visualized as a tangible,

insurmountable edge. Representative frames of a visitor’s

virtual journey through Ptolemy’s universe are included in

figure 8.

Figure 8: Frames extracted from the animation simulating a

viewer’s virtual journey through Ptolemy’s universe

In the second journey the participants experienced Leonardo’s

revolutionary concept of an open, dynamic universe part of an

infinite time. The participant’s view could span freely in any

direction across an open system of planets moving along

elliptical orbits. The virtual journey never ended, as the space

has no visible, reachable limits. The animation suggested a

sense of spatial-temporal infinity which enshrouded the viewer

throughout the duration of the voyage. Representative frames of

a visitor’s journey through Leonardos’s universe, showing

close-up views of the sun, planets and moon, are included in

figure 9. We note that the frames in figure 9 show the point of

view of the participant, therefore they do not represent the

correct size of the sun and planets in relation to each other.

Overall, the visitors’ comments and reactions were very

positive and enthusiastic. A selected group of participants (12)

was asked to fill out a survey containing rating questions related

to key aspects of the exhibition. More specifically, the subjects

were asked to use a 5-point Likert scale (1=lowest score;

5=highest score) to rate the following features of the

installation: usability, comfort, accessibility, spatial setting,

visual quality, quality of interaction, degree of immersion,

innovation, and overall quality of the experience. The mean

rating values are reported in table 1.

Figure 9: Close-up views of sun and planets extracted from the

animation simulating a viewer’s virtual journey through

Leonardo’s universe

Feature Mean Ratings (1-5)

Usability 4

Comfort 4

Accessibility 4

Spatial setting 4

Visual quality of content 4

Quality of interaction 4

Degree of immersion 4

Innovation 5

Overall quality of the

experience

5

Table 1. Survey results (mean rating values)

5. DISCUSSION AND CONCLUSION

In this paper we have described a VR exhibit developed for the

Leonardo’s museum in Vinci Italy. The purpose of the exhibit

was to communicate the contrast between Leonardo’s

revolutionary concept of a heliocentric universe and Ptolemy’s

geocentric system. The setup of the installation consisted of a

low-cost portable immersive system with head and hand

tracking technology and passive stereo. The visual content

included 3D animated reconstructions of the heliocentric and

geocentric cosmological models projected onto a single flat

screen. The viewer sat in front of the screen wearing a pair of

passive polarized glasses and navigated through the

environment using a 6DOF (degrees of freedom) wand or pinch

glove.

Although the audience’s reactions were very positive, the

exhibition presented some weaknesses. For example, several

visual details of the animated models created in Maya were not

able to display correctly in the VR environment because of

problems related to real-time rendering pipelines and file

translation from the 3D software to the real-time environment.

This loss resulted in a lower visual quality of the 3D content

and therefore in a less engaging user experience. In addition,

the installation did not provide a “fully immersive experience”

because of limitations of the hardware system. According to

Slater et al. (Slater, 1996) immersion is a quantifiable

characteristic of a technology and is defined by the extent to

which VR devices are extensive, surrounding, inclusive, vivid

and matching. VR systems are considered extensive if “they can

accommodate many sensory systems”; they are surrounding if

the information arrives at the participant’s sensory organs from

any (virtual) direction; and they are inclusive to the extent that

all sensory data from reality is excluded. Vividness refers

primarily to resolution and quality of the visual display, as well

as richness of the information content, and matching refers to

the correspondence between the “participant’s proprioceptive

feedback about body movements and the information generated

on the displays”. Although our installation met the

requirements of vividness, matching, and, to a certain extent,

inclusiveness, the system was not extensive, nor surrounding. It

provided visual feedback only (sound and haptic feedback were

not included), and the information content arrived at the user

from only one direction (the screen).

Further, it can be argued that the major weakness of the exhibit

was its limited interactivity. However, restricting the interaction

to travel through the environments was the authors’ choice,

primarily determined by the purpose and content of the exhibit.

The goal of the installation was not to let the viewers

manipulate objects but to let them explore the two universes,

observe objects from unique and diverse points of view, and

directly experience the differences between the two

cosmological models. We anticipate that the content of future

VR exhibits will lead to development of more sophisticated

interaction experiences which will require object selection,

manipulation, and dynamic change of the virtual content.

Despite its limitations, the exhibit was very successful and the

audience’s reactions confirmed the effectiveness of VR

technology as a visualization, research, education,

dissemination and entertainment tool. This project can be

considered a first case study which paves the way for the design

of a novel museum space and for the establishment of a new

technology infrastructure that will allow the introduction of VR

exhibitions in the Leonardo’s museum. The new museum

environment will include a CAVE-like VR system with

multiple screens and multi-sensory feedback, therefore many of

the limitations listed above will be overcome.

5.1 References and/or Selected Bibliography

References from Journals:

Hedberg, J., and Alexander, S., 1994. Virtual Reality in

Education: Defining Researchable Issues. Educational Media

International, 31, pp. 214-220.

Hirose, M., 2006. Virtual Reality Technology and Museum

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31-36.

Interacting with "Machine Culture". IEEE Computer Graphics

and Applications, September/October 1993, 13(5), pp. 4-8.

Roussou, M. and Efraimoglou, D., 1999. High-end Interactive

Media in the Museum. Computer Graphics, ACM SIGGRAPH,

pp. 59-62.

References from Books:

Sherman, W.S. and Craig, A.B., 2003. Understanding Virtual

Reality. Morgan Kaufmann, San Francisco, CA.

Van Gent, R., 2003. Andreas Cellarius, Harmonia

Macrocosmica - Multilingual Edition. TASCHEN Books,

Germany.

References from Other Literature:

Akins, A.S., 1992. Virtual Reality and the Physically Disabled:

Speculations of the Future. In: Proc. of Virtual Reality and

Persons with Disabilities Conference, California State

University, Northridge.

Dalgarno, B., Hedberg, J., and Harper, B., 2002. The

contribution of 3D environments to conceptual understanding.

In: Proc. of ASCILITE 2002, New Zealand.

Gaitatzes, A., Christopoulos, D., Voulgari, A., and Roussou,

M., 2000. Hellenic Cultural Heritage through Immersive Virtual

Archaeology. In: Proc. of VSMM 2000 - 6th International

Conference on Virtual Systems and MultiMedia, Japan.

Leonardo da Vinci. Codex Arundel, 1490s–c1518. British

Library, London, UK.

Leonardo da Vinci. Codex Atlanticus, 1478 to 1519. Ambrosian

Library, Milano, Italy.

Leonardo da Vinci. Codex F, 1492-1516. Institute of France,

Paris.

Leonardo da Vinci. Notes and drawings relating to the moon.

Codex Hammer (ex Leicester), 1504-1506. Gates Collection,

Seattle (Washington) USA, c. 2r.

NCAC (National Center on Accessing the General Curriculum),

2003. Virtual Reality/Computer Simulations. Curriculum

Enhancement. U.S. Office of Special Education Programs.

Roussou, M., 2000. Immersive Interactive Virtual Reality and

Informal Education. In: Proc. of User Interfaces for All:

Interactive Learning Environments for Children, Athens,

February 2000.

Roussou, M., Kavalieratou, E., and Doulgeridis, M., 2007.

Children Designers in the Museum: Applying Participatory

Design for the Development of an Art Education Program. In:

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and Children, June 6-8, 2007, Aalborg, Denmark, pp. 77-80.

Slater, M., Linakis V., Upshot M., Kooper, R., 1996.

Immersion, Presence, and Performance in Virtual

Environments: An Experiment with Tri-Dimensional Chess. In:

M G (ed.), ACM Virtual Reality Software and Technology

(VRST), pp. 163-172.

Youngblut, C., 1997. Educational Uses of Virtual Reality

Technology. In: VR in the Schools - coe.ecu.edu, 3(1).

References from websites:

Autodesk Maya 2008. http://www.autodesk.com (Accessed on

20 May 2008)

Britannica Online Encyclopedia. Cosmos: Christian Aristotelian

cosmos.

http://www.britannica.com/eb/art/print?id=3029&articleTypeId

=0 (Accessed on 20 May 2008)

Calanca, R., 2007. L’astronomia e l’ottica di Leonardo da

Vinci. In: Astronomia Coelum Online.

http://www.coelum.com/index.php?goto=articoli&id=22&p=5

(Accessed on 9 June 2008)

Copernicus, N., 1543. De Revolutionibus Orbium Coelestium.

http://ads.harvard.edu/books/1543droc.book/ (Accessed on 2

June 2008)

NASA’s planetary exploration program.

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5.2 Acknowledgements

This project is supported in part by the Museo Leonardiano in

Vinci, Italy, by Universita’ degli Study di Pisa, department of

Civil Engineering, Italy, and by the Envision Center for Data

Perceptualization at Purdue University, USA.