web3d dance composer: a web-based ballet performance

16 | Papers | ISEA2002

Web3D Dance Composer: A Web-based Ballet Performance Simulation System

SOGA Asako

Graduate School of Human Informatics, Nagoya University

[email protected]

Abstract

This research approach focuses on sharing 3D animation data over the Web and creating a system capable of animating virtual ballet performances. Sharing motion data on the Internet allows anyone to access various artistic dances all over the world. In addition to this, these motion data can be applied in online systems for educational and artistic purposes. I present Web3D Dance Composer, which enables the creation and editing of classical ballet animation based on VRML. This system allows anyone to easily create and simulate artistic ballet performances as well as realistic stage effects. Since it is important for classical ballet to provide an artistic harmony from both dance choreography and stage&scenario effects, this system can be useful for teachers and choreographers to simulate their performance in advance. This system also allows artists opportunities and possibilities to express their feelings.

1. Introduction

Although many researches on dance using 3-dimensional(3D) human animation through motion capture systems have been recently developed, little attention has been given to share and use those motion data on the Internet. My research focuses on sharing 3D animation data over the Web and creating a system capable of animating virtual ballet performances.

For many years, various animations have been composed by using applications for choreography [1][2]. Such applications, though widely used until now, do not work on the Web and they are not suitable for online applications. Sharing motion data on the Internet allows anyone to access various artistic dances all over the world. In addition to this, these motion data can be applied in online systems for educational and artistic purposes. For example, one can prepare 3D movement catalog, compose pieces by collaborating via the Net, and exhibit pieces on an electronic dance museum.

My goal is to develop and integrate several modules into a system capable of animating realistic virtual ballet performances on the Web. I present Web3D Dance Composer, which enables the creation and editing of classical ballet animation based on Virtual Reality Modeling Language (VRML) [3]. This system allows anyone to easily create and simulate artistic ballet performances as well as realistic stage effects. Since it is important for classical ballet to provide an artistic harmony from both dance choreography and stage&scenario effects, this system can be useful for teachers and choreographers to simulate their performance in advance. Moreover, this system also has other possibilities regarding ballet dance performances. For example, users can change human characters to animals such as dogs and cats, or they can appreciate the performance from any imaginary seat such as a moving seat and a dancer’s viewpoint. This system

also allows artists opportunities and possibilities to express their feelings.

This paper describes a research framework to develop the ballet performance simulation system and shows a dance performance example actually generated by it.

2. Sharing and reusing motion data on the Web

I developed a simulation system that can easily create balletperformances on the Web. In this work I focus on a number of issues related to sharing and reusing motion data. As there are a lot of steps to choreograph classical ballet, it is difficult to collect all steps. The concept underlying my system foresees an increasing accumulation of these data, and their distributed storage over the network for sharing and reusing by users.

The main issue to share and reuse dance motion data over the Net is describing human motion. For this purpose, I adapted H-Anim [4], a standard way of representing humanoids inVRML, to a human model of a female ballet dancer [5].

I further segmented some motion sequences as basic ballet steps. Such independent motion data sequences make it easy to access and recompose actions easily as well as reuse the same data. I also handle characters and motion data independently. This allows us easily to change costumes or characters as well as to change motions. This allows character designers to simulate these ballet animations with their own characters.

Figure 1 shows an image of the sharing and reusing motion data by using this system. Basic steps and solo dances are increasingly captured and made available on the Net. Users may use such data to create their composed steps. Teachers and choreographers can save their own choreography. On the other hand, students and the other users can see and use new arrangements of created archives.

Character Designers

Basic Steps

Teachers and Choreographers

Composed Steps

Solo dances

Characters

BasicSteps

Students

Users

Figure 1: Sharing and reusing motion data

ISEA2002 | Papers | 17

Motion Database

Human Model

Dance Animation Generation System

Archive RegistrationSystem

Stage Production Simulation System

Web3D Dance Composer

Other objects Back

ground

WWW

Figure 2: System architecture of WDC

Figure 3: User interface of WDC

3. Web3D Dance Composer (WDC)

3.1 System overview

Web3D Dance Composer (WDC) is a Web-based ballet performance simulation system. Using motion capture data, one can easily compose and simulate various ballet performances. This system consists of 3 subsystems: a dance animation generation system, an archive registration system, and a stage production simulation system.

The dance animation generation system interactively creates a series of arrangements of a dance from basic ballet steps previously captured from professional dancers. The archive registration system registers the dance sequences that may be new arrangement of dance archives created by the dance animation generation system. Using these registered animations, the stage production simulation system creates a dance performance according to a scenario. Users can interactively simulate various stage effects such as costumes and background.

As a result from the use of the three subsystems described above, users can finally create classical ballet performances on the Web.

Figure 4: Recording motion data by a professional dancer

Number Examples

Basic Steps (including Arrangement)

160(300)

Assemblé, Glissade etc.(Assemblé Ouvert etc.)

Solo Dances 15 Cupid Variation etc.

Table 1: The number of motion data and examples

3.2 System architecture and user interface

Figure 2 indicates the system architecture of WDC. This system consists of 3 subsystems and motion database. The motion data of basic steps should be prepared on the motion database. The other object files such as characters for the human model and background object data can be stored on the Web and users can add more files.

Figure 3 shows the user interface of WDC. It employs only one window, which consists of a virtual environment based on VRML and a Java Applet including menus for each subsystem. All the requirements to run this system are a WWW browser and a VRML Plug-in. This system works on general Windows PCs.

3.3 Motion database

Each dance has its own style and composing process. Especially in the case of classical ballet, there are typical steps and methods that have to be considered. Thus, in order to compose a virtual choreography, my research group proposed a method for segmenting motion data and describing classical ballet steps on the computer [6]. In addition to this, we constructed a motion database of basic steps, which were performed by professional ballet dancers. We have about 160 basic steps and some arrangement steps for each basic step. We also have some solo dances for classical ballet. For capturing motion data, we used both an optical motion capture system and a magnetic system for 5 dancers because it is difficult to use the same systems and dancers to gather all steps. Figure 4 shows a recording scene using the magnetic system. Table 1 shows the number of steps and some examples of our motion database.


4. Functions of each subsystem

4.1 Dance animation generation system

Since classical ballet is a dance that typically consists of established steps, one can compose ballet choreography by connecting basic steps. I constructed a dance animation generation system by using these steps [7]. This system easily allows dancers and teachers to generate the arrangement of a dance.

The dance animation generation system roughly consists of 3 parts: Step List, Time Line and Control Panel. All names of steps are listed in Step List. Composed steps are shown in the Time Line. In the Control Panel, there are some buttons for the following functions:

(1) Previewing: The user can preview each step at any timebefore he/she adds it to the timeline.

(2) Speed Control: The system supports to change beat foreach step because choreograph is usually depend on the beat like music. It also supports to change tempo to play.

(3) Editing: The system supports to add and delete steps toedit the list of steps. It also supports to change the turn of steps.

At the beginning, there is a character on the 3D world and there is no animation. To make choreography, the user provides a sequence of steps in Time Line by selecting steps from the Step List. Each step has some options such as left/right and beat. After making a list of steps, one can load the corresponding animation to the character. Once the user loads the animation, he/she can play it anytime. Figure 5 shows an example of composed steps. To connect some steps, each action can be translated and interpolated.

4.2 Archive registration system

The archive registration system is used for registering the dance sequences that may be new arrangement of dance archives created by the dance animation generation system. In the present system, 10 of composed steps that have choreographed by a ballet teacher for beginner’s lesson are already registered. The user can use these composed steps as well as he/she can appreciate those. This system also registers previously captured solo dances in classical ballet and characters for the human model that based on VRML H-Anim.

Solo Dance1

Composed Steps2

ComposedSteps3

Actor3 (4dancers / line)

Actor1(1dancer)

ComposedSteps1

Actor2 (8dancers / circle)

Figure 6: An example of scenario

Figure 7: Characters for the human model

4.3 Stage production simulation system

Using registered animations, the stage production simulation system creates a dance performance according to a scenario. Figure 6 shows an example of scenario for a dance performance. The user can post the composed steps or solo dances to the timeline for each actor. He/she can simulate different animations for multi-humans. In order to represent an attractive ballet stage, I prepare the display control system that has the following functions:

(1) Character: The user can change the character for thehuman model, some of which are predefined as shown in Figure 7. These characters, as well as any other character on the Web,can be easily changed in accordance with users interests.

(2) Background: Since the system supports VRML files inwhich some objects are defined, users can freely adapt the stage characteristics as they like.

(3) Formation: One can copy the figure of the dancer withthe same choreography to simulate more than one of dancers dancing together. In addition to this, it is also possible to change the formation of dancers.

Composed Steps1 Step2: Soussous Step3: Pirouette Step1: Piqué

1 2 3 4 5 6 7 80Beat

Figure 5: An Example of composed steps


Figure 8: Dance Performance Example 1

Figure 9: Dance Performance Example 2

5. Dance performance examples

Figure 8 and Figure 9 show the screen shots of danceperformance examples actually generated by WDC. In the case of Figure 8, all dancers perform the same composed steps on a virtual stage. 8 dancers are arranged in a circle around a dancer. Figure 9 is a little complicated case. 9 dancers perform 3 kinds of composed steps, and the background location is a recreation of “Sakae,” the downtown area in Nagoya City.

6. Conclusion and future works

I presented a Web-based ballet performance simulationsystem combining a dance animation generation system, an archive registration system, and a stage production simulation system. My proposed system is capable of not only composing choreography, but also simulating scenarios and several stage productions. I verified that this system could successfully simulate some dance performance examples. In addition to this, I could effectively share and reuse motion data on the Web. This allows anyone great opportunities and possibilities to use precious motion data.

In the future work I intend to augment the composing system by supporting functions such as the body part manipulation. I will develop an automatic choreography system for actual ballet lessons.

Acknowledgement

My Special thanks are due to for providing us with the motion capture studios in Warabi-za Digital Art Factory and School of Design and Architecture, Nagoya City University to capture the classical ballet motions. I also wish to thank to ballet dancers. Among them are Noriko Ogawa (Chieko Sassa Ballet), Kumiko Katoh, Yuko Shimura (Noriko Kobayashi Ballet Theatre), Yurie Shimomura, and Kaori Maruyama (Star Dancers Ballet). I also extend my thanks to Prof. Shigeki Yokoi, Prof. Takami Yasuda, Prof. Bin Umino, and Mr. Kengo Hayashi for their cooperation.

Work in progress and current documents may be found at http://pinakes.soc.toyo.ac.jp/BIN/webdance/ . This Web site also contains the proposed system, Web3D Dance Composer.

References

[1] Credo Interactive, Life Forms3.9, 2001,http://www.credo-interactive.com/

[2] Warabi-za Digital Art Factory, 2000,http://www.warabi.or.jp/buyo-fu/

[3] Web3D Consortium, VRML97 Specification, 1997,http://www.web3d.org/Specifications/VRML97/

[4] VRML Humanoid Animation Working Group, The VRMLHumanoid Animation specification, 2001,http://www.h-anim.org/Specifications/H-Anim2001/

[5] A. Soga, M. Endo, T. Yasuda, B. Umino and T. Kaiga,"Standardization of Dance Motion Data Using H-animwhich are Gathered by Motion Capture Systems and itsApplication; Construction of a Motion Data Archive forClassical Ballet", Proceedings of the IPSJ-SIGCHSymposium, Japan, 2001, pp.41-48, Japanese.

[6] A.Soga, M.Endo, and T.Yasuda, "Motion Description andComposing System for Classic Ballet Animation on theWeb," Proceedings of 10th IEEE ROMAN, France, 2001,pp.134-139.

[7] A. Soga, B. Umino, and T. Yasuda, "A Web-basedInteractive Choreography Simulation System for Ballet",The Journal of the Society for Art and Science, Vol.1, No.1,2002, pp.30-38, Japanese.


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web3d dance composer: a web-based ballet performance

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