+ All Categories
Home > Documents > A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia...

A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia...

Date post: 24-May-2020
Category:
Upload: others
View: 2 times
Download: 0 times
Share this document with a friend
26
HAL Id: inria-00069884 https://hal.inria.fr/inria-00069884 Submitted on 19 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. A Very Large Scale Virtual Environment for multimedia conferencing Thierry Parmentelat, Alexis Gourdon, Thierry Turletti, Élodie Larreur To cite this version: Thierry Parmentelat, Alexis Gourdon, Thierry Turletti, Élodie Larreur. A Very Large Scale Virtual Environment for multimedia conferencing. [Technical Report] RT-0296, INRIA. 2004, pp.22. inria- 00069884
Transcript
Page 1: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

HAL Id: inria-00069884https://hal.inria.fr/inria-00069884

Submitted on 19 May 2006

HAL is a multi-disciplinary open accessarchive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come fromteaching and research institutions in France orabroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, estdestinée au dépôt et à la diffusion de documentsscientifiques de niveau recherche, publiés ou non,émanant des établissements d’enseignement et derecherche français ou étrangers, des laboratoirespublics ou privés.

A Very Large Scale Virtual Environment for multimediaconferencing

Thierry Parmentelat, Alexis Gourdon, Thierry Turletti, Élodie Larreur

To cite this version:Thierry Parmentelat, Alexis Gourdon, Thierry Turletti, Élodie Larreur. A Very Large Scale VirtualEnvironment for multimedia conferencing. [Technical Report] RT-0296, INRIA. 2004, pp.22. �inria-00069884�

Page 2: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

ISS

N 0

249-

0803

ap por t t e ch n i qu e

Thème COM

INSTITUT NATIONAL DE RECHERCHE EN INFORMATIQUE ET EN AUTOMATIQUE

V-EYE

A Very Large Scale Virtual Environmentfor multimedia conferencing

Thierry Parmentelat — Alexis Gourdon — Thierry Turletti — Élodie Larreur

N° 0296

May 2004

Page 3: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone
Page 4: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

Unité de recherche INRIA Sophia Antipolis2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France)

Téléphone : +33 4 92 38 77 77 — Télécopie : +33 4 92 38 77 65

���������� � ���������������������� �!��"�#$���&%('*)+�!�-,�'/.01'2"

34,�� .5#$�!"��6.017/���8�9,�'$34 ��1'$����'/�

:+;�<>=@?A?AB(CEDF?HGI=@J�KL=NMODPK∗ Q-R MS=UT�<SVXWZY\[�?H]-Y\J † Q :+;�<S=N?H?AB^:E[�?AMS=_KHKL< ‡ Qa` M>Y�]�<>=ZbcDF?H?A=@[�? §d egfAh*i2j1kmlon�prqtsvuwfAh*iHs1x�yNh*h2zg{g|}x6~_{Nu�s

�a��yU��i6u ����~_{gi�u�i�c~_�g�PyN�vu u�iAx�eg{g|}�@zgi�{F���@�U�_��n�l�~Lq$�U�N�U��n��_�2��~U�NiAs

�X�-�A�6�4�g�_�_� d eg|}sc��~_�PiA�E tiHswx6�w|�¡PiHsc~+�g��yUu�yUu�qr�Fi�~U�g�g��|}x6~4u�|¢yN{£{�~Uh�iA Z¤2¥w¦r§-¦/uwe�~Uu¨|�h*���¢iAh*iA{@u�s¨~©�~U���_i�ptxA~U��i�ª¨|��vu�z�~U�¬«a{r­@|���y_{gh�i6{@u2®>©�prªE«9¯!°\x�yNh�¡g|�{g|�{g�±~±²N³µ´�y_���� �°guwi�¶ru�z�~U��h*iHsws�~U�NiAsA°gh�z��·u�|·¸h�iH t|�~�x6y_h�h�zg{�|�xA~4uw|�y_{Ps1~U{� /¹c|��_eZ³Ei�º�{g|¢uw|�y_{£­r|} ti6yP»¼½egiA{¾ gi6­_iA�¢yN�g|�{g�/¤2¥w¦r§-¦\°�y_zg�m�g��|¢h+~_�wq£�_y@~U�-´�~Nscu�y$x6�wiH~4uwi*~X����~Uuv¿Ày_��hoswzg|·u�~U¡g��i�¿ÀyN��iA~_sw|��¢q

i6¶t�PiA�w|�h�i6{@uw|�{g�£h�zg�¢uw|�h�iA t|}~£u���~_{�svh�|}swsw|�y_{Á°Á´1|¢uwe&~£�}~U���_i*{rzgh�¡Fi6��yU¿ ��~U�wuw|}x�|���~U{@u�s6°-~U{� ¾y_{�egi6uv¸iA�wyN�_iA{gi6yNz�s�ÂÃ�^{gi6u�´9yN�wÄtsA°ri_» ��»Åx�yNh�¡g|�{g|�{g�+~2­Ni6��q+�Py4´�i6�w¿Àzg�\¡�~Nx�Ä@¡Fy_{�i�swz�x�e£~_s ªmd1¹¨³2°tuwyN�_i�u�egi6�´1|¢uwe+´1|���iA +©¬ÆEǨsA°@~NsÅ´�i6���P~_sa¼(©¬Æ¨ÇEs�|�{�uwe�i¨Âëa«a«ÉÈ_�N�g»¢ÊNÊ�¿Ë~Uh�|¢��q_»-ÂÃ{±��~_�vu�|�x6zg�}~U�H°4uweg|}sa����~Uuv¿Ày_��h|}s�­_iA�wqIz�svi6¿Àzg� ¿Ày_�Xi6­4~U��z�~4u�|¢{���u�egiÌswxA~U�}~U¡g|���|·u�q&y_¿¨u���~_{�svh�|}swsw|�y_{I���wy_uwytx�yN��s�~U{P Iu�egiÌswzg�g�Fy_�wu�y_¿ g|·Í\i6��i6{@uw|}~4u�iA /sviA�w­r|}x�iHs�¿ÀyN�1h�zg�¢uw|�h�iA t|}~+~U���g�¢|}x6~Uuw|�y_{�sA»¤2¥w¦r§�¦�z�swiAsmu�egi£Î\Ï\Ð�Ñ�¦�x6y_h�h�zg{�|�xA~4uw|�y_{¾~U��x�eg|¢uwiAx�uwzg��i_»*ÂÃ{�uweg|}s�~U���g�wy@~_x�eÁ°�~_�_i6{@u�s��PiA�v¿ÀyN�wh

~��wiH~U�¢¸>u�|¢h�i±h+~_�g�g|�{g��y_¿1uwegi/�_iAy_�N��~_�geg|}x+~U��iA~Z|�{@uwy�sw��~Uuw|}~U� ~U��iA~_s�´1egyNswiXsw|¢ÒAiAs* ti6�Fi6{P &y_{Iuwegi gi6{�sw|·u�q�~U{P +�¢ytxA~4uw|�y_{+y_¿Á��~U�wuw|}x�|���~_{Nu�s6Ó@iA~Nx�e+yU¿\uwe�iAswiEx�iA�¢�}s9|�s9~_s�svytx�|}~4u�iA �´1|¢uweX~�h�zg�¢uw|}x6~Ns�u��_��y_zg�Á»ÂÃ{$uwe�|�s1´ ~Lq_°riH~_x�eX�P~U�wuw|}x�|���~U{@u1x6~U{$¿Àytx�z�s yN{$e�|�s1~_�wiH~�y_¿�|�{Nu�i6��iAsvuA°g~_{� X��iAx6i6|�­_imy_{g��q�uwe�i��wiA�¢iA­L~_{@uu���~UÔ±xU»ÕZÖ@×\Ø�Ù�Ú �4Û-�_� h�zg�¢uw|�h�iA t|}~�x�yN{t¿Ài6��i6{Px�|�{g��°UÂÃ��h2zg�¢uw|}x6~_svuA°rs�x6~U�}~U¡�|¢��|·u�qN°U­r|¢�wuwzP~U�giA{@­r|��wyN{gh�i6{@uA°N�-d ���i�ÜPiAx!u�y_�H°t¹c|��_eZ³¨i6º�{g|¢uw|�y_{£ª¨|} tiAy

∗ ÝÀÞ-ßÁÝáà�âAã!äHåLæèç�à-é�ê>æëä_ã!ìëæëívîLï�ð4ñvò�ó!ó!ôgõ}ö�÷�óvøLò�ù�ú�ò�û�÷�ú�ü6ý�þwÿ!ðUñv÷tõOñÃù�óLñw÷tõ��6ó† ÝÀÞ-ßÁÝáà�âAã!äHåLæèç�à-é�ê>æëä_ã!ìëæëívî��6û�ò��Lñ�ý@õ��6þ���ó6þwù6ü6ý�þwÿ!ð4ñv÷tõSñÃù6óLñv÷gõ��!ó‡ ÝÀÞ-ßÁÝáà�âAã!äHåLæèç�à-é�ê>æëä_ã!ìëæëívîLï�ð4ñvò�ó!ó!ôXï���ó6û�ò�ú!úLñvü6ý�þwÿ!ð4ñv÷tõSñÃù�óLñv÷tõ���ó§ � � ß������tç�éLéLæëã!é@î4ò�û!þ�LñvòtõÀû�÷�ó!ó�ò���ó�ü�ógõ��!ó�÷�ù���ò�úAò�û�ò���þÃø\õ���þÃø

Page 5: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

���������� ' 1'2)+�!��,�'/'$c.01'2" )+�!��"�#/1����"¬����� ������'/7$��1��$1�6��

,�#$� �6�8�9,�'/3�� ��1'$��5.5#$�!"��6.��17/��� �� ����� � � Çcy_zPs¨�g���Aswi6{@u�y_{�sc �~U{�sEx�i���~_�g|�i6�¨z�{gi2~_�g�g��|�xA~4uw|�y_{Zi6¶t���A�w|�h�i6{@u�~_�¢i�¡�~_�tuw|}s��6i�¤2¥w¦r§�¦�@zg|P|¢h��g���6h�iA{Nu�iczg{±h�yN{� tic­r|��vu�zgi6���muw��fAsa�N��~_{� ti��Hx�egi6���¢iN°_i6u��@zg|Px6y_h2¡g|¢{�i1zg{±h�y_{� gici6{±²N³�°@ tiAsh�iHsws�~U�NiAs9uwi6¶@u�zgi6�}sA°g tiAscx6y_h�h�z�{g|�xA~4u�|¢yN{�s�h�zg�¢uw|�h��A t|}~�i�uc�}~*ª¨|} ��6y±¹E~Uztu�i�³���ºP{g|·u�|¢yN{�»j9i� ��6­_iA�¢yN�g�Fi6h�i6{@u¬~��PyNzg�Á¡gzgu¬�g��|¢{�x6|¢�P~U�_ ti9x����6i6��z�{giÅ�g�}~4uwi6¿Ày_��h�ia�Nz�|_�Fi6��h*i6uvu�ia  � i6¶t���A�w|�h�i6{t¸

u�i6��x6y_h�h�yr ��6h�i6{@u� tiHsmuw��~U{�swh�|�s�sv|�y_{PsEh2zg�¢uw|�h!�H t|}~Z~L­_iAx*zg{��N��~_{� Ì{gyNh�¡g��i+ ti+��~_�vu�|�x6|¢��~_{@u�s�i�uswzg�� tiHsE���AswiA~_zt¶Ìe��6u��6��y_�Nf6{giHs6°�~L­NiAx��P~U��i�¶ti6h��g��i�zg{gi+ tyN��s�~U��i�u��wfHsE��~U��|� ti�x�yNh�h*i*ªEd1¹E³�°� tiAs���As�~Uzg¶��¢ytxA~Uzt¶ÌºP��~_|¢��iAs�yNz�s�~U{Psmº��9 ti+�}~/¿Ë~Uh�|��¢��i±È_�@�t»�Ê_ÊN»*«�{���~U�wuw|}x�zg��|�i6�H°�x�i6uvu�i+�g��~Uuwi6¿Ày_��h*i+iHs�uu��wfHs�ztuw|��¢i��Fy_zg�"�A­L~_�¢z�i6� �¢iHs x6~U�P~_x�|¢u��Hs  tiE�P~_s�sw~_�_i��2�#� �Hx�egi6���¢i� tiHs �g�wy_uwytx�yN�¢iHs9 gi¨u���~_{�svh�|}swsw|�y_{Á°ri�u��i�svz��g�PyN�vu¨ gi�swi6��­r|�x6iAs1 t|¢Í$�6��i6{�x6|%�Hs �PyNzg�1�¢iHs1~U�g���¢|}x6~Uuw|�y_{�s h2zg�·u�|¢h��H t|�~�»¤2¥w¦r§�¦I��i6�FyNswi$swzg���&� ~U��x�eg|¢uwiAx�uwzg��i$ gi/x6y_h�h�zg{�|�xA~4uw|�y_{(Î\Ï\ЬÑ�¦\»É³E~_{�s�x�i�uwuwi£~U�g���wytx�egiN°a tiAs

~_�_iA{Nu�sc~_s�swzg�wiA{@uc�¢i* ��Ax6y_zg��~_�_i�iA{ZuwiAh*�Ps¨���6iA�� ti��}~±ÒAy_{gi��'�6yN�_��~U�ge�|��@zgi�i6{�Ò6y_{�iAsc tyN{@uE�}~�u�~_|¢���¢i ��6�Fi6{� Ì gi��}~+�Py@sv|¢uw|�y_{Zi6um ti2��~X ti6{�sw|¢u��2 giAsc�P~U�wuw|}x�|���~U{@u�sAÓ\x�e�~_x6zg{gi� ti2x�iAsEx�iA�¢��zg��iAsEiAsvuE~_s�svytx6|%�Ai�2zg{$�_��y_zg�Fi¨h2zg�·u�|�xA~_svuA»a³Eimx6i�uwuwi�h+~U{g|�f6��i_°tx�e�~N�Nz�i¨��~_�vu�|�x6|¢��~_{@u��Fi6ztucswimx6y_{�x6i6{@uw��i6��svz�� s�~�ÒAy_{gi (� |�{@u��6��)�uH°ti�uc{gi���iAx6i6­Ny_|����@zgi���imuw��~4ºPx�x�yN�w��iAsw�Fy_{� g~_{@uA»* Ú �H� Ø �'+ � �£� x�yN{t¿Ài6��i6{Px�i�h2zg�·u�|¢h��H t|�~�°Ph2zg�¢uw|}x6~_svuEÂÃ��°F��~_s�s�~U�_i,�X�&� �Ax�egiA�¢��i_°Pi6{r­r|¢��y_{�{gi6h�i6{@u¨­r|��v¸u�zgi6�S°g����Ü�iHx!u�i6zg�c��d ��°g­r|� ��6y�e�~Uzguwi� ��6º�{g|¢uw|�y_{

Page 6: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� ²

+ ,�'�"-1'�"��,.-*/ �A� Ú Û �-�U�10 Ú / 2

354768�9#8;: Ö �t����� Ö � <

2>= Ú : � Ù �t� Ö �±�4�@?�0Ë� Ö �U� �¬� Ö A²�»¢Ê kE­Ni6��~U����~U��x�eg|·u�iAx�uwzg��i »�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» B²�» �DC�EGF2~_{� IHKJ�L±x�yN{t¿Ài6��i6{Px�|�{g�*uwyry_�}s »m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» M²�» ² ¹¨|¢�NeZ ti�º�{�|·u�|¢yN{£³E|��_|¢u�~U��ªE|� gi6y »�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» M²�» � ¹E~U�� t´ ~U��im~_{� /ptyU¿áu�´ ~U��im�1iH�@zg|¢��i6h�iA{Nu�s »�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» �

<DN�? ÖPORQTSTU 8 � Ú �WV Ú / Ö / � X�P»¢ÊZYEsviA�csw~Uuw|}s�¿Ë~Nx!u�|¢yN{$h�i�u��w|}x�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊH��P» � ƨ�_iA{Nu�s �wiHsv�Fy_{Psv|�¡g|��¢|¢u�qµ»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊH��P» ² l�~U�g�g|�{g��|�{t¿Ày_��h+~4uw|�y_{ »�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊNÊ�P» � �Å~_�vu�|�x6|¢��~_{@u�sv¸>u�yU¸ÃÆc�_iA{@u x6y_h�h�zg{�|�xA~4uw|�y_{ »�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊL��P» B l�~U�g�g|�{g�+~U���_yN�w|¢uwe�h�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊL�

A5[]\ V Ö �^0 � Ö / �A� + XÖ � � +Ë�A� ,_2Bg»¢Ê Ǩi�u�´�y_��ı tiAs�x���|��tuw|�y_{£~U{� /h�iA~Nsvz��wiAh*iA{@u9u�y@yN��sÉ»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊH²Bg» � «a¶r�Fi6��|�h*iA{@u¨swx6i6{�~_�w|�yNsm»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» Ê@BBg» ² «a¶r�Fi6��|�h*iA{@u�s1´1|¢uweZ~UzP t|¢y*u���~UÔ+x »m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» Ê^MBg» � «a¶r�Fi6��|�h*iA{@u�s1´1|¢uweZ³1ª ­r|} ti6y*uw��~4Ô±x5»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊHÈBg» B ©�~U���_im�PyN�gzg�}~4u�|¢yN{ »�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»m»�»�»�»�»�»�»�»�»�»�»�»m»�» ÊHÈ

`>a Ú �PV-�g�@0>� Ú / Ù 0Ë�%? Ú �%? Ö �Ibc0À�L� ����+ [ /�d 0À� Ú / � Ö / �H� , X

e a Ú / � + �-�%0 Ú / � / Ûgf ������� Öih Ú �1j 3�k

l m '2"¬��,+7/#$��"���,�'

¼¾i2º���svuE�N|¢­Ni2~_{Ìy4­_iA�w­r|�i6´�yU¿au�egi�~U�g�g��|}x6~4u�|¢yN{�x6~_��~U¡�|¢��|·u�|¢iHs2®>sviHx!u�|¢yN{��_¯�°Á~U{� £u�egi6{¾ tiAs�x���|�¡Pi2uwegi~N ty_�guwiA �svy_¿áu�´�~_�wi*~U��x�eg|¢uwiAx�uwzg��i$®>sviHx!u�|¢yN{¾²@¯!°�u�e�~4u�|�s�­4~Ns�u��¢qZ¡�~NsviH �yN{��gz�¡g�¢|}x���q�~L­4~U|��}~U¡g��i��g|�iAx6iAsy_¿-swyU¿áu�´ ~U��i_°t~U{P $�N|¢­NiE|�{� t|}x6~Uuw|�y_{�s yN{/uwegi��g�}~4uw¿Ày_��h ��iA�@zg|��wiAh*iA{@u�sA»Æ¨�¢h�yNsvua~U���gx�yNh*h2zg{g|}x6~Uuw|�y_{*´1|·u�eg|¢{�¤2¥w¦r§�¦2z�swi ÂÃ��h2zg�·u�|�xA~_svuA»-¼�i1�N|¢­Ni�¿Àz��vu�egi6�a ti6u�~_|¢�}s�y_{2uwegi

Î�ÏFÐ�Ñ�¦$x�y_h��Fy_{giA{@u�®>sviHx!u�|¢yN{/�r¯!°ru�e�~4uc|}scx�iA{@uw��~U�\´1|·u�e£�wiHsv�FiAx�u1uwy*uwegi�h2zg�¢uw|}x6~_svu1z�s�~U�_i�svuw��~4u�i6�_qN»Æc¿áuwi6� ~�swiAx�uw|�y_{± tiH t|�xA~4u�iA �u�y� t|}swx6z�swsw|�{g��swy_h�ici�¶t�Fi6��|¢h�iA{Nu�~U�P�wiHsvzg�¢u�sE®ËswiAx�uw|�y_{IB_¯�°N´�ic�g��y4­r|� gi

~�x�y_h���~_�w|}swy_{*´1|·u�e±yUu�egi6�9�wiA��~UuwiA *­r|��vu�z�~U�Pi6{r­r|¢��y_{gh�iA{Nu�sc®ËswiAx�uw|�y_{±�@¯!°r~U{� +x6y_{�x6�¢z� gicy_{+�FyUu�i6{@uw|}~U�u���~Nx�Äts�¿ÀyN� ¿Àztuwz��wi�´�y_��ÄÌ®ËswiAx�uw|�y_{�MU¯!»

ß � é�n�o�p�q�r

Page 7: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

� � ����( �"�� ����^� �*� �^���

� ���\���&� 341��"�#$����d e�iX¤�¥�¦r§�¦½®Ëª¨|��vu�z�~U��«aq_iL¯�~_�g�g��|�xA~4uw|�y_{&~_|¢h+s2~4u2 tiAh�y_{�svuw��~4u�|¢{g�Ìuwegi±¡Fi6{�i�ºgu�s2y_¿1h�zg�¢uw|}x6~Ns�u�ÂÃ�svuw��iA~_h+s�¿ÀyN�*|�h��g��i6h�i6{@uw|�{g��~�ªÅi6��q&©¬~U���_i£ptx6~_�¢i/ª¨|��wuwz�~_�1«a{r­@|���y_{gh�i6{@uZ®Ë¤�� Î��E¯!»�d egi£�_y@~U��|�su�y�x�yNh�h�zg{g|}x6~UuwiX~_h�y_{g�Ì~Ìswi�u*yU¿1��~_�vu�|�x6|¢��~_{@u�s�u�e�~4u*h+~Lq�s�x6~U��i±zg�&uwyZu�egi$swi6­Ni6��~U�Åu�egy_z�s�~U{P gs6»«9~_x�e±��~_�vu�|�x6|¢�P~U{@u9h�y4­_iHsa´1|¢uweg|�{$~*swq@{@u�egi�u�|�xE²_³ �_iAy_�_��~U��eg|�x ´�y_���} �°@~_{� +u�qr�g|}x6~_�¢��q�sviA{� gs sviA­_iA��~_�svuw��iA~_h+s9y_¿� �~4u�~�

����-Û�0 ÚÌx�yN{Nu�i6{@uc~_s1xA~U�tu�zg�wiH X¡rq±e�|�s1h�|}x���y_�ge�y_{giN°

�d 0ËÛ ÖrÚZ~_s1x6~_�tuwz��wiH X¡rq$~*´�i6¡\x6~_h/°

�uwi6¶@u�z�~U� � Ö �A�H�� Ö � ~_s�u�qr�FiA /~4u1u�egi�x�yN{�svyN�¢iN°t~U{� 

�+ Ú �N�t�%0 Ú / h�iHsws�~U�NiAs svy*u�e�~4uceg|}s h�y4­_iHs�~_�wi�x6y_���wiHx!uw��q+iAx�e�y@iH ±u�y�yUuwe�i6�1��~_�vu�|�x6|¢��~_{@u�sA»

�-|��_zg��i�Ê �ÅÆ s�~Uh��g��i�sw{�~_��sve�yUu1yU¿Å~�¤�¥w¦t§�¦/sviHswsw|¢yN{

�-|��_zg��i&ÊÌ|��¢��z�svuw��~4u�iAs+u�egiAswiZ¿Àzg{Px!uw|�y_{Ps6°¨~_{�  uwe�i�~_ � t|·u�|¢yN{�~U�¨¿ÀiA~Uuwzg��iZuweP~4uX´�iÌ|�h*���¢iAh*iA{@uwiA ´1|¢uwe�|¢{̤2¥w¦r§�¦�°P{�~_h�i6��q/~+­r|��vu�z�~U�¬h*y4­r|�i�uwegiH~4u�i6�H°guweP~4um~_�¢��y4´cs�¸9���wy4­r|} tiA $uweP~4uEswztÔ±x�|�i6{@u¨¡�~_{� r¸´1|} ru�e&|�s2~L­4~U|���~_¡g�¢i±¸¨uwy�´�~Uu�x�e&~Zh�y4­r|¢iXh�zg�¢uw|}x6~Ns�u�iA �|�{I¹c|��_eI³Ei�ºP{g|·u�|¢yN{I³E|¢�N|·u�~U��ªE|� gi6yÉ®�� �m¯

ÝÀÞ-ßÁÝáà

Page 8: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� B

¿ÀyN�wh+~UuA»�d eg|�sa¿ÀiA~Uuwzg��icsvz��g�PyN�vu�sa²_³¨¸O�PiA��sw�PiHx!u�|¢­Nic t|�sw�g�}~Lq�y_¿Fu�egic­r|} ti6y�x6y_{@uwiA{NuH°N~Nsa´�i6����~_sÅh�|¢¶t|¢{g�y_¿Åuwegi�~UzP t|¢y$svyNzg{� ru���~Nx�Ä$´1|¢uwe�uwegi2yUuwe�i6�m��~U�wuw|}x�|���~U{@u�s �F~Uz� t|�y$svuw��iA~_h+s6»mÆc����u�egi2~_z� t|�y$svuw��iA~_h�s~_�wi�~U�}swy*��i6{P ti6��iA X|¢{Z²_³2°�swy+~_s�uwy��g��y4­r|� gim��iA~_�¢|}svuw|}x¨|�{� t|}x6~Uuw|�y_{�s y_¿�u�egi�svyNzg��x�im�Py@sv|¢uw|�y_{Á»

� �^0 / � 0 V�+ Ö�Ú : + Ú �_��+�0À� ×���d egiI()���&|�{Ìu�egi2��y4´�i6�¨��|��_e@umx6y_��{gi6�E�_|�­_iAsm~U{�y4­_i6��~U���Á­r|�i6´µy_¿auwegi´�y_���} �»¬ÂOuÅ~U�}svy�swegy4´cs6°Lh�y_��i�|¢{@uwiA�wiHs�u�|¢{��_��q�¿Ày_��y_zg�-�gzg���FyNswi_°4u�egi1 t|·Í\i6��i6{@u��¢iA­_iA��s-yU¿�"!�� �1��� &��'�K&1&���!°yN����&������!°ru�e�~4u �wiHsvz��·u9¿À�wyNh u�egi�x�zg���wiA{@u9svi6uvu�|¢{g�@s6»Åd egim��|¢�NeNu��_��~Lq2~_�wiH~�|�s9u�egi¨yN{gi¨´1egiA�wiE´9imx6~_{eP~L­_i�~_z� t|�yX~U{� Ì­@|} tiAy$x�yN{@u�~_x�u�sA°F~Ns¨i6¶t�g��~_|¢{�iA £¡Fi6��y4´�»md egi2h�iA t|�zgh �_��~LqXÒAy_{gi*svz��w��y_zg{P t|¢{��±|·u|}s�u�egi±sv�P~_x�i+´1e�i6��i*y_uwegiA���Fi6y_���¢i±xA~U{¾¡PiXswi6iA{�|¢{¾uwe�i+­@|��wuwz�~_�a´9yN�w�} �»+¼½egiA{�|¢{¾u�eg|�s2~U��iA~�°�uwegi g|·Í\i6��i6{@uc��~_�vu�|�x6|¢��~_{@u�s�|¢{/u�egi�­r|�x6|¢{g|¢u�q$~_�g�FiA~U�1~Ns�uwegiA|¢� ��$@��� ���!°gu�y_�_i6uwegiA�1´1|·u�eZ~* g|�svuw|�{�x!u�|¢­Ni�*� �����|�x�uwzg��i±u�e�~4u+~U���¢y4´cs�uwy¾�wiHx�yN�_{g|�Ò6i+u�egi6h£» �-|¢{P~U���¢q�u�egi/ �~U��ľ�N��~Lq¾~U��iA~Ì gi6�g|}x!u�s�u�egi/Ò6y_{�i±¿À��y_h´1e�i6��im{�y*|�{t¿ÀyN�wh+~4u�|¢yN{$|}s1x�z��w��i6{@uw��q±��iAx6i6|�­_iA Á»d egi�´�i6���·¸OÄr{gy4´1{�x�yN{t¿Ài6��i6{Px�|�{g�1uwyryN��s C�EGF�®Ëª¨|} ti6y�j9y_{t¿ÀiA�wiA{�x�|�{g�r¯� �Ê@M��g~U{P �HKJ�L�®>�1y_¡�z�s�uÅÆczP t|¢y

d�yry_�á¯� M���~U�g�FiA~_�c|�{$u�egi�zg�g�Fi6�E�¢i6¿áu¨x�yN�w{giA�A»ad e��wyNzg�_e$uwegiHsvi�uwyry_�}s�uwegi�z�sviA�cx6~_{/eP~L­_i�~Uz� g|¢y+~U{P ­r|} ti6y+x6y_{@u�~Nx!u�s�´1|¢uwe/uwe�i���~U�wuw|}x�|���~U{@u�s �¢ytx6~UuwiH X|�{/uwegi���|¢�Ne@u �N��~Lq+ÒAy_{giN»

� ��,�3H"�� ���� � �-��/��"�1��"�#X������� ����� �"!�#�#$!%��&�')(+*,� &-*".�"�ÂÃ{^yNzg�±­r|¢�wuwzP~U�c´�y_���� Á°�swy_h�iÌx�yNh��PyN{gi6{@u�sX~U��i£svu�~Uuw|}xZsvzPx�e(~_s*uwe�iÌ´9yN�w�} É|·u�sviA�·¿�°1´1eg|���iÌyUu�egi6��s6°��|�Ä_i�uwe�i���~U�wuw|}x�|���~_{Nu�s6°P~U��i� tqr{�~Uh�|}xU»ckE{gi��FyNs�sv|�¡g��i�~U��x�eg|·u�iAx�uwzg��i�|�scuwy±z�swi�~±s�x�iA{gi��_��~U�geZsvuw��z�x!¸u�zg��i$�g��y4­r|� giA �¿ÀyN��i�¶g~Uh��g��i$¡rq&~�h�yr gi6���¢|�{g�¾��~_{g�_z�~_�_i/svz�x�e ~_s*ªE�¨lÌ©a°a~_{� &u�y����wyN�_��~Uh�uwegi|�{@uwiA��~Nx!uw|�y_{Ps9|�{0/NÆ�ª�Æ�°g��|¢ÄNi�i_» ��»�|¢{ZlZ|�h+~UÒAi�¸Ã²_³1 �ÊA²2�O»d eg|}s-~U�g�g��yN~Nx�e�|�s�´9yN�wÄ4~_¡g�¢i9~_sÁ��y_{��E~_sÁuwegiA�wi�~U��iÅ¿Ài6´I��~U�wuw|}x�|���~U{@u�sÁ|�{�uwegi9´9yN�w�} �»�¼�i9�g�wi6¿Ài6���wiH 

u�y�z�svi�~*h�y_��imÜ�i�¶t|�¡g��i�~_�g�g��yN~Nx�eX´1eg|}x�e$eP~_s�uwe�i�¿Ày_���¢y4´1|�{g�+x�e�~U��~_x�uwiA�w|}s�u�|�xAs ��Y¨swi$x6z�s�u�y_h�|�Ò6iA �­Ni6��sv|�y_{�y_¿ C�E�F£~U{�  HKJ�L�x�y_{g¿Ài6��i6{�x6|¢{g�£u�yry_�}s6°-¿Ày_�2h+~4¶t|¢h�|�Ò6|�{g��swyU¿áu�´ ~U��i�wi6¸SzPsviN»

�Y¨swi$354-6 78 È2��~Ns�uwegi�x6y_h�h�zg{�|�xA~4uw|�y_{/h�iAx�e�~_{g|}svh ´1|¢uwe C�EGF�~U{� cHKJ�LF»

��1i�¸Oz�swiE~Nsah�zPx�e±~_sa�FyNs�sw|¢¡g��i1u�egiE³1ª¨¸SyN�w|�i6{@u�iA +x�yt ti¨¿À�wyNh ³cªEdcp9 �ÊA�2�F¿Ày_�� tiA~_�¢|�{g��´1|¢uweXuwegi³1ª ­r|� gi6y+s�u��wiH~Uh£»

�Y¨swi2y_¿auwe�i+kE�Fi6{�:�©É��|¢¡g��~U��q$¿Ày_�muwegi�²_³ ��i6{� gi6��|¢{g�XyU¿�yNzg�m �~4u�~�°Fuwy_�Ni�u�egi6�m´1|·u�e��Fy_�wu�~_¡g��iuwyry_��Är|·u�s ¿Ày_�1h+~_{�~U�N|¢{g�±kE�Fi6{�:�©¾´1|�{� ty4´cs�®;:�©�Y¨d ~U{� 0:�©�YcÂv¯!»

�Y¨swi�yU¿�~U{�kE�w|�i6{@u�iA r¸vkE¡t��iAx�u����wyN�_��~Uh�h�|¢{g�2��~_{g�_zP~U�_i�®Sj�<=<�¯�u�y±s�u��wz�x�uwzg��i�y_zg�1 g~Uu�~�»ÆEsm~X�wiHsvz��·uH°Pu�egi�svy_¿áu�´�~_�wi�u�e�~4u�|¢h��g��i6h�iA{Nu�smiA~_x�e���~U�wuw|}x�|���~U{@u � sEx���|¢iA{Nu�|}sE tiA�g|}x!uwiH Ì|�{̺��Nzg��i

�g»d egi1|�{@uwiA�v¿Ë~Nx�iAsa´1|·u�e2u�egi¨x6y_{t¿ÀiA�wiA{�x�|�{g�muwyry_�}sÅ~U{P 2´1|¢uwe�u�egi¨³1ª½­r|�i6´�i6�Å´1|��¢�P¡Pic gi�u�~_|¢��iA *|�{�uwegi

¿ÀyN�¢��y4´1|�{g�mswiAx�uw|�y_{�sA» �gy_�Å{�y4´�°U�¢i6uaz�sasvuw��iAs�s-uwe�~UuÅuwegic²N³c¸vkE�Fi6{�:�©/��i6�g��iAswi6{@u�~Uuw|�y_{*~U���¢y4´cs�~�¡Fi�uvu�i6�zPsviA�¨|�{Nu�i6��~_x�uw|�­@|¢u�q$~_{� £eg|��_egiA�¨�Fi6�w¿Ày_��h+~U{�x6i_°Psw|�{�x�i*kE�Fi6{-:�©�|�sm~±svu�~_{� g~U�� £svz��g�PyN�vu�iA £¡rq/h*y@s�u�N��~_�geg|}x6~_�Áx6~U�� gsA»9pryNh*i�{�|�x6i�i�Í\iAx�u�s¨xA~U{£¡Fi�iA~Nsv|��¢q$~_ g tiH ZsvzPx�e£~Ns uwi6¶ruwzg��|¢{���°�swe�~_ gy4´cs6°t��i�Ü�iHx!u�s6»��yN�vu�~U¡g��i¨u�yry_��Ä@|¢u�s�¿ÀyN�1h+~U{�~_�_|�{g�2yNzg�¨kE�PiA{�:�©�´1|�{� ty4´cs�®;:�©�Y¨d ~U{� 9:�©�Y¨Âv¯ ~U��im~_��swy2zPsvi6¿Àzg��uwyiH~_sw|¢��q±x���iA~Uuw|�{g�+~�sv|�h��g�¢i�zPsviA�v¸O|¢{@u�i6�w¿Ë~_x�iN»

ß � é�n�o�p�q�r

Page 9: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

� � ����( �"�� ����^� �*� �^���

�-|¢�Nzg�wi����ÅÂÃ{Nu�i6��{�~U��~_��x�eg|¢uwiHx!u�zg�wi�y_¿-~*ªc¸Oi6qNi�x6�¢|�i6{@uc|�{�svu�~U{Px�i

ÝÀÞ-ßÁÝáà

Page 10: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� M

����� ����� !����� �� &������ � �"��� & (���� *�����#��d-~UÄr|�{g�$~N t­4~U{@u�~_�_i2yU¿au�egiXÎ�ÏFÐ�Ñ�¦Ì~_��x�e�|·u�iAx!u�zg��i���iA�@zg|��wiHs C�EGF±~U{� 7H J�L/uwy/¡Fi*~_¡g�¢i2uwy£sw´1|·u�x�eÌuwy~_{�~U��¡g|¢uw��~U��qXh2zg�·u�|�xA~_svuE�N�wyNzg�Zzg�Fy_{Ì��iA�@zgiHs�uH» �gyN�¨|�{�svu�~U{Px�i_°\´1egiA{�~±�P~U�wuw|}x�|���~U{@uEx6�wy@swswiAsc~$x�iA�¢�¡Fy_z�{� g~U��q_°ru�egi�¤�¥�¦r§�¦$�g��yrx6iAs�s�|�s1{�yUuw|¢º�iH X¡rq+u�egi�Î\Ï\ЬÑ�¦$~U�Ni6{@u uwe�~Uu1|·u¨swegy_z��� $z�swi�~U{gy_uwegiA� swi�uy_¿�h2zg�·u�|�xA~_svuc�_��y_zg�Ps6»d eg|}sm|�sm tyN{gi2¡rq/uwe�i*swqr{�x�eg��y_{g|�ÒA~Uuw|�y_{Z~U��x�eg|¢uwiAx�uwzg��i����wy4­r|} tiA £¡rq£uwe�i 354-6 7$®ËlÌiAs�sw~_�_i�¡�z�s�¯

È2�O»Id egi 354-6 7/x�yNh�h�zg{g|}x6~Uuw|�y_{&h�iHx�e�~U{g|}swh5e�~_s*~�sw|�h*���¢iZ~_ � t�wiHswsw|�{g��~U{P &h�iAs�sw~_�_i/svqr{@u�~U¶\»Æ1xAx�yN�� t|�{g�$uwy/uwe�i±x�zg���wiA{@u�x6i6���a´9i+xA~U{�sviA{� �~/h�iAs�s�~U�_i2uwy C�EGF±y_� HKJ�L\°\uwi6����|¢{g�£u�egi6h ´1egi6{�uwyx�eP~U{g�Ni�uwegiA|¢��~N g t��iAs�s¨�N�wyNzg�Á»�¼�i*e�~N Zuwy$h�yr g|·¿Àq C!EGF±~U{P iHKJ LZswy$~Nscu�y$e�~_{� t��i�u�egiAswi�sv�FiAx6|·ºPx{�i6´ ® 354-6 7A¯ h�iAs�sw~_�_iAsA»Æ¨{gyUu�egi6�9h*yt t|¢ºPxA~4uw|�y_{+´ ~_s��Fi6�w¿Ày_��h�iA �|�{+y_�� ti6�auwy�Ä_iAi6�)HKJ�L�|�{t¿Ày_��h�iA *yU¿\u�egic��yrxA~4u�|¢yN{+yU¿\uwegi

y_uwegiA�c��~_�vu�|�x6|¢��~_{@u�sA°�svy±~Ns uwy$~U���¢y4´ ¿Ày_�¨~+sw|�h*���¢i�²N³c¸Ã~UzP t|¢y+��i6{P ti6��|¢{��£®>~4uwuwi6{rz�~Uuw|�y_{Ì~Nx6x�yN�� g|¢{g�N�¢qu�y��Py@sv|¢uw|�y_{�s1~_{� /y_��|¢iA{@u�~4u�|¢yN{�s�yU¿�sv�FiA~_Ä_i6��s ~U{� $��|�svuwiA{gi6�!¯!»���;� � (�� '�)�� !� ( *"(�����" (���( *,!�#$# (%�&�d e�i � � svu�~_{� g~_�� �°F~_sE ti�º�{�iA Z|�{ÌÂë�j ��ÊAÈ_²_��°g|}sE{gy4´�´1|� tiA�¢qZ~N ty_�tu�iA £|�{ÌegyNh*i�­@|} tiAyX ti6­r|}x�iHs6»d e�i6��i±~U��i±x�zg���wiA{@uw��q�{rzgh�i6��y_z�s�svy_¿áu�´�~_�wi�|�h*���¢iAh*iA{@u�~4u�|¢yN{�s�u�e�~4u2 giA~U�9´1|·u�e�uweg|}s�¿ÀyN�wh+~UuA°-h*y@s�uy_¿�u�egi6h�~U|�h*|�{g�Z~4u�iH~_sw|¢{g�/��yrxA~U��|�{Nu�i6��~_x�uw|�y_{�sm¡Fi�u�´�i6i6{�~/x6~_h*iA��~/~U{P �~£x�yNh��gztuwiA��¿Ày_��xA~U�tu�zg�v¸|�{g�P°�h*|¢¶t|¢{���°Á~U{P Ì�g�}~Lqr|¢{g�/­r|� gi6yNsA»�ÂÃ{�yN�� gi6�EuwyZ~_sE´9iA�¢�Å~N g t��iAs�s¨��i6h�yUu�i2i6¶gx�e�~U{g�NiAsA°Fuwegi�³1ªEdcpx6y_{�swy_�wuw|�zgh ®� B�á¯� ti6º�{giH �~U{� �|¢h��g��i6h�iA{Nu�iA �~U{�iA{�x6~_��svz���~Uuw|�y_{¾yU¿�u�egi � � ¿ÀyN�wh+~4u�|�{�~U{��-d �svuw��iA~_h ®+ �ÊA�g°ÁÊA�t°g� �á¯�»ÆEsc��~_�vucy_¿-u�egi�³1ªmdcp£svqtsvuwiAh ~_sc�g�wy4­r|} tiA /~4u¨uwegi�~_¡Py4­Ni��¢ytx6~Uuw|�y_{Á°guwegi('GC�)+*+,�'*u�yry_�¬|}sc~_¡g�¢i

u�y$swi6{� �~ � � s�u��wiH~Uh ~_sv¸O|�s¨´1|·u�eg|¢{¾~U{���d � s�u��wiH~Uh£»�k¨¿�x�y_z���swi�uwe�|�s�svuw��iA~Uh xA~U{Ì¡Fi*swi6{@uEuwy$~h2zg�¢uw|}x6~_svu2~N g t��iAs�s�|·¿¨ tiHsv|���iA �»/ÂOu�s2x�y_z�{Nu�i6����~U�wu�|�s�{�~Uh�iH .-/'GC�)103254�~_{� �~U���¢y4´cs�uwy� t|}sw�g��~Lq�uwegisvuw��iA~_h swi6{@u1¡@q6'GC7)+*+,8'F»

9 ~_sw|}x6~U����q_°t´�imeP~_ Xuwy+h+~UÄNi¨u�egi�¿Ày_���¢y4´1|�{g�+x�e�~_{g�_iHs�u�y:'�C�)+*+,8'�u�y�ºgucy_z��1{gi6iH gs ��sv���¢|¢u1uwegi �i��x6y_{@uwiA{@u |�{@uwy�u�´�y+s�u��wiH~Uh+s  tiA t|}x6~UuwiH Xu�y�­@|} tiAy�~_{� /~Uz� t|�y��wiHsv�FiAx�uw|�­_iA�¢qN»

�uw��~U{�s�x�yt ti�u�egi$~_z� t|�yÌs�u��wiH~Uh uwy�swy_h�i+´1|} ti6��q�~L­L~_|¢�}~U¡��¢i±~_z� t|�y£¿Ày_��h�~UuA°Åswy£uwe�~Uu HKJ L¾x6~_{�g�}~Lq±|·uEh*|¢¶tiA /´1|¢uwe/uwegi�yUuwe�i6�1��~_�vu�|�x6|¢��~_{@u�s ­_yN|�x6iAsA»Åd¬y�u�e�~4uciA{� /´9i�x6y_zg�} Xy_¿�x6y_zg��swiEu�~UÄNi~_ t­4~_{Nu�~U�NiayU¿ruwe�i<;�E>=8'�C$ ¢ÊL���r�¢|�¡g��~U��q_°H´1egyNswia�gzg���FyNswia|�s��g��iAx6|�swi6��q¨u�y¨�g��y4­r|� giÅiA~_swqmi6{�x6yr g|¢{g�~U{� £ tiHx�yt t|�{g�*¿À�wyNh ~U{P ±u�y�uwegi � � ¿ÀyN�wh+~4uH»ÂÃ{£~_ g g|·u�|¢yN{Xu�y�u�e�~4uH°g´9iE¿Ë~_x6iA ±uwegi�¿ÀyN�¢��y4´1|¢{���|}swswzgi_»apry+~Ns�u�y2¡Fi�x�yN{�sw|�svuwiA{Nu ´1|¢uwe$uwegi*Î\Ï\Ð�Ñ�¦

�P~U��~_ t|��_h£°\uwe�iAswi2u�´�yZs�u��wiH~Uh+s�sve�y_zg�} �¡Fi±swi6{@u�y4­_i6��~/h�zg�¢uw|}x6~Ns�u��N�wyNzg�Ìu�e�~4u�swegy_z��� �­4~U��qÌy4­_iA�u�|¢h�iXswy�~Ns�uwyZ¿ÀyN�¢��y4´ uwegi�Î\Ï\ЬÑ�¦¾h+~U���g|¢{���°-|>» i_»£u�yÌ�_iAy_�_��~U��eg|�xA~U���¢qZh+~Uu�x�e�uwe�i±h�y4­@|�i�uwe�iA~4u�i6���ytx6~Uuw|�y_{Á»ÂÃ{�y_�� tiA��uwyZsvyN�¢­Ni*uwe�~Uu�|�s�svz�i_°¬´�i+~_ tyN�tuwiH �uwegi�¿ÀyN�¢��y4´1|¢{��/�P~4uwe¬»+¼�i±svu�~_�vu�iA �¿À�wyNh uwe�i�uwyry_�

{P~Uh�iA  H_L@? LGHKJ+,�)�|�{g|·u�|�~_�¢��q���~U�wu¬y_¿tuwegi HGL@? L82/2/;8)��P~_x�Ä4~U�Ni� �gÊ��S»-d eg|}s¬´�y_��Äts\uwegi9¿Ày_����y4´1|¢{g�1´ ~Lq\Ó4|·uu�~UÄNiAs¬~Ns¬~_{�~U���_zgh�iA{Nu-~¨swi�u�y_¿���d ��svuw��iA~Uh+s9®À|S» iN»¬ÂÃ��~N g t��iAs�s%<ÉiA­_i6{��Fy_�wu�{rzgh2¡PiA��¯�°U~U{� ��wiA�PiH~4u�siA­_iA�wq£��~Nx�Ä_i�u�~U����|¢­r|�{g�XyN{�y_{�i*y_¿auwe�iAswi�svuw��iA~_h+s¨u�yXu�egi

n − 1yUu�egi6��svuw��iA~Uh+sA°\|¢h��g��i6h�i6{@u�|¢{g�Z~

h2zg�¢uw|¢¸O t|���iAx!u�|¢yN{�~U����d �½��i�Ü�iHx!uwyN�A»

ß � é�n�o�p�q�r

Page 11: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

È � ����( �"�� ����^� �*� �^���

p@u�~U�wuw|�{g�m¿À�wyNhµu�e�~4uÅu�y@yN�>°_´9i1´1��yUu�i#H_L@?/=32��/,�F+*1u�e�~4u�~Nx!u�s�i�¶g~_x�uw��q�uwegics�~Uh�i ´ ~Lq_°Ui6¶tx6i6�tuÅu�e�~4uu�egi�svi6u y_¿Áu�~_�w�Ni�u �-d �^svuw��iA~Uh+s9h+~Lq*¡Fi�h�yr g|·º�iH XyN{+uwe�iEÜPq�uweg��y_zg�Ne$~2svh+~U����svi6u1yU¿�x6y_h�h+~U{� gs|}s�svzgiH XyN{Xu�egi�svu�~U{P g~U�� X|�{g�gzguA»kE{+u�y_�$yU¿�uweP~4uA°r´�i¨´1��yUu�icuwe�i )_F+2 H8*+=32��@,�F+*mztu�|¢��|·u�q\Ór|¢u�|}s9~2sv|�h��g��i�Î\Ï\Ð�Ñ�¦+x���|�i6{@u�u�e�~4u�u�~_Ä_iAs

~Ns1~U{£~U���_zgh�iA{Nu ��~2ºg¶tiA /�_iAy_�_��~U��eg|�xA~U�F�¢ytxA~4uw|�y_{$¸Åu�qr�g|}x6~U����q+uwegi�h�y4­r|�iEu�egiA~UuwiA�A°

�~�ºg¶tiA ^h2zg�¢uw|}x6~_svuX�N�wyNzg� ¸�u�qr�g|}x6~U����qIu�egi�yN{giZ´1egi6��i 'GC�)+*5,8'�u���~_{�swh*|¢u�s+uwegi¾³1ª ~_z� t|�ys�u��wiH~Uh£°

�~U{� £~_{���|¢{@uwiA�wiHs�u1��~_ t|�z�s��4»ÂOu±u�egi6{½¡P~_sw|�xA~U���¢q�¿ÀyN�wÄts+~_{ |�{�svu�~_{�x�iZy_¿ HGL@?/=32��@,�F+*�y_{^|·u�s+ºg¶tiH  ��d � svuw��iA~_h/° ~U{P Iu�egi6{

~N L��z�svu�s u�egi�swi�ucyU¿-u�~_�w�Ni�uc��d �½s�u��wiH~Uh+s�uwy±~�swyU¸Ãx6~U����iA $Ò6y_{�imy_¿-|�{@uwiA�wiHs�uHÓruweg|}scÒAy_{gi�|}scx�yNh*��ztuwiH ~NsÅu�egimswi�u�yU¿�x6i6����s�uweP~4u9|�{@uwiA��swiAx�u�s9´1|·u�e$~�s��@z�~U��icx�iA{@uwi6��iA X~4u�u�egiEºg¶tiA +��ytx6~4u�|¢yN{X~U{P ±~_s9��~_�w�Ni¨~_su�egi�|�{Nu�i6��iAsvu1��~N t|¢zPs6»d egi�º��_zg��i�²+swegy4´cs1egy4´ ~_�¢�¬uwegiHsvi�iA�¢iAh�i6{@u�s¨|¢{@uwiA��~Nx!u¨~_{� £egy4´�´9i�~Nx�eg|�i6­_i�u�yXswi6{� /u�egi2³1ª

svuw��iA~_h+s�u�y�uwegi�~_�g�g��y_�g��|}~4uwim��d �(s�u��wiH~Uh+s6»

�-|��_zg��i�²��Å�aztuwuw|�{g��uwyN�_i6uwegiA� uwegi )_F+2�H�*+=32��/,!F+*�ztuw|��¢|¢u�q

ÝÀÞ-ßÁÝáà

Page 12: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� �

����� � ! �3�� ! �"� ! ���� ��� *�� ! �"��� � .)(+���� ��� *��ÆEs�yU¿muwyt g~LqN°9¤2¥w¦r§�¦É´�y_��Ärs*yN{Iu�egiÌ©Á|�{rzt¶É�g�}~4uw¿Ày_��h£»^¹¨i6��i£|�s�u�egi£�¢|}svu±yU¿muwegiZ��iAx6y_h�h�i6{� tiH x6y_{tºP�_zg��~4u�|¢yN{±¿Ày_�c~Nx�eg|�i6­r|¢{���u�egi�¡PiHs�uc��iAswzg�¢u�s |�{/uwi6��h+s yU¿-�wiHsv�Fy_{�sw|�­_i6{�iAs�s �

� � 0>�V�+Ë� × �gÛ-� V-� Ö � � ¤2¥w¦r§-¦Z¡Fi6|�{g�±h+~_s�sv|�­_iA�¢q/¡�~NsviH £y_{�kE�Fi6{t¸+:�©�¿Ày_��²_³¨¸O�wiA{� ti6��|�{g��uwegi­r|¢�wuwz�~_��´�y_���} �°P|¢u�|�sEeg|��_eg��q£�wiHx�y_h�h�i6{P tiA £u�yXz�swi2~_{Ì{r­r|� t|}~±­r|} ti6y/~_ g~_�tuwiA�A°F¡FiAx6~_z�swi�uwe�|�s t��|¢­Ni6��yUÍ\i6��s�¿Àzg�¢�Psvzg���PyN�vu�¿Ày_�ÅeP~U�� t´�~_�wi6¸O~Nx6x6i6��i6��~4uwiH �kE�PiA{t¸ :�©/zg{P ti6�a©¬|¢{rzt¶�»-ÂÃ{�¿Ë~Nx!u�uwegiA�wisvz��g�Py@sviH t��q±~U��iEswz�x�e$ t��|�­_i6��sÅ¿ÀyN�1~U���Fh+~U��y_��­r|} ti6y�~_ �~U�tu�i6��h�~_{rzt¿Ë~_x�uwzg��i6��s6°@¡gztucswi�uwuw|�{g�2z��svzPx�e£ g�w|�­_iA��s9uwz��w{giH XyNztu1uwy�¡Fi�­_iA�wq+u�iA t|�y_zPs6»

�h Ö ���_� � �-uwe�i��aeg|��¢|���sc´�i6¡\x6~_h |}s �g�wi6¿Ài6���wiH ±¿ÀyN�1�_yryt $~N g~U�gu�~4u�|¢yN{X´1|¢uweg|�{iC�EGF �_�2�SÓ

�� �-Û�0 Ú ��Û-� V-� Ö � �)HKJ�L�´ ~_s�´1��|¢uvuwiA{É~£¿ÀiA´ q_iH~U��s�~U�Ny�~U{P �|�s2{gy_u*~L´ ~U��i+yU¿1uwe�iX�}~4uwiHs�uƨ©-ptÆ �wiA­r|�sw|¢yN{5 �Ê �O»� ay_z�uwerz�s�{�i6iA �uwy/z�swi+~U{�~_z� t|�yZ~_ g~_�tuwiA�¨u�e�~4u�x�yNh�iAsm´1|·u�e�~U{�k�p�p t��|¢­Ni6�H°ty_�1 ti6���¢y4qXÆE©�ptÆ�´1|¢uwe/u�egi2k�pgp@¸Ãx�yNh*�P~4uw|�¡g|��¢|¢u�q+¿ÀiH~4uwz��wi�i6{P~U¡g��iA �»

� ��� �ruwegimegyNsvu�uwe�~Uu ��zg{�s�uwe�i$'GC�)+*+,�'*swyU¿áu�´ ~U��i1¿Ày_�1swi6{� t|�{g�2uwegimh�y4­r|¢i�x�yN{Nu�i6{@u�s9{giAiA gs9uwye�~L­_i*~+º���i6´1|���i��PyN�vuH°�~U{� �´9i2e�~_ £u�yX�Ny±¿Ày_�Euwe�i��g» �P» �gÊ�Ä_iA�w{giA�¬|�{�yN�� tiA�cu�yXe�~L­Ni�uwe�i*³1ªx6~_�tuwzg��i�´9yN�wÄ+���wyN�PiA�w��q_»

� � /�������� � ��,�. ,�'$1'2"ÂÃ{£u�i6��h+s1yU¿Å{gi6u�´9yN�wÄ/~U��x�eg|·u�iAx�uwzg��i_°tu�egi6��i�~_�wimu�´�y±i�¶ruw��i6h�iN°�~U{� £iH�@z�~U���¢q${�~U|�­_iN°P~_�g�g��yN~_x�e�iAs9¿Ày_�|�h��g��i6h�i6{@uw|�{g��u�egimuw��~4Ô±x�s�u��wiH~Uh+s ¡Pi6u�´9iAi6{£~_x�uwy_��s ´1|¢uweg|�{Z~*¤�� Î � �

�d egi � / 0Ë�_���6� Ø�Ú / + ×±~U�g�g��yN~Nx�e�´9yNzg�� ���iA�@zg|���iÅi6­_iA�wqm��~_�vu�|�x6|¢��~_{@u�uwy¨i6¶t�g�¢|}x�|¢uw��q�~_swÄEeg|}s�{gi6|��_et¸¡PyN��s�u�y+zg{g|}x6~Ns�u uwe�i6|��1y_ztu��_y_|�{g�+svuw��iA~Uh+s9uwy+e�|¢h£Ó

�d egi �10 / �+ ÖNØ � � +Ë�%0>�_�g�A� ~_�g�g��yN~Nx�e/|}s1u�egi�yN{gi�´1egiA�wi�i6­_iA�wqXu�qr�Pi2yU¿�x�yN{@uwi6{@u¨|}s¨~Nswsw|��_{giH /~sv|�{g�N�¢i�h�z��·u�|�xA~_svuc�_��y_zg�Á»«�~Nx�e�yU¿ uwe�iAswi±h�i�uwe�yr �s��g��y4­r|� ti+|¢u�s2y4´1{��g��yNs�~_{� �x�yN{�s6»£d egi/sv|�{g�_��i+h�z��·u�|�xA~_svu2~U�g���wy@~_x�e

swi6iAh+s-uwy�egiA�¢��h+~_svuwiA��u�egic��iA�@zg|��wiH �¡�~_{� t´1|} ruwe¬°_¡gztu9zg{t¿Ày_�wuwz�{�~4u�i6��q�|¢h��g��|�iAsa~_{*|�{� t|�­r|� gz�~U�t¡�~_{� r¸´1|} ru�eZuwe�~UuE�N�wy4´cs ��|¢{�iA~U����q$´1|¢uweZu�egi�u�yUu�~U�¬{rzgh2¡PiA�¨y_¿a��~U�wuw|}x�|���~U{@u�s6»cÆEscy_���Py@sviH £´1|·u�eZuweg|}smsv|¢uv¸zP~4uw|�y_{¬°�u�egiXz�{g|�xA~_svu2~U���g�wy@~_x�e�~U���¢y4´cs�uwy�|�h��g��i6h�i6{@u*~Ì{gyUu�|¢yN{�yU¿c­r|�x6|¢{�|·u�q�¸E�g��y4­r|� giA �uwe�~Uu*~_{~_�g�g��y_�g��|}~4uwi�|�{t¿À��~_svuw��z�x!u�zg�wi�|}s¨ tiA�g��y4q_iA $¸�¡�ztuEegy4´�i6­Ni6��uwe�i�¡Py_uvu�y_h �¢|�{gi�|}s1u�e�~4u¨yN{/uwegi2zg�g��|¢{gÄ\°iH~_x�e±�P~U�wuw|}x�|���~U{@u�e�~Nsau�y*swi6{P �uwegi�s�~Uh�iEsvuw��iA~_h ~Ns�h+~_{@q*u�|¢h�iAs ~Nsaegime�~_s9|�{Nu�i6��iAsvuwiH +{gi6|��_er¡Fy_��s6°´1e�|�x�e£~U�@~U|�{$|}s�¿Ë~U� ¿À��y_h yN�tuw|�h+~U�Áz�{� ti6�cswy_h�i�x�yN{� t|¢uw|�y_{�sA»kEzg�1�NyN~_��|�s�u�y+¡gzg|��� /­r|¢�wuwzP~U��´�y_���� gs ~_¡g�¢i�u�y+swxA~U��iEu�y+�Py_uwiA{Nu�|�~_�¢��q+u�egy_z�s�~U{P gs yU¿�h�i6h�¡Fi6��s y_�

h�yN�wiN»�Î\Ï\ЬÑ�¦/|}s¨~XswxA~U�}~U¡g��i�h�zg�¢uw|}x6~Ns�uw¸S¡P~_swiA £x�yNh*h2zg{g|}x6~Uuw|�y_{Z~U��x�eg|¢uwiAx�uwzg��im¿Ày_�m©¬~U���_i6¸Ãpgx6~U��imª¨|��v¸uwz�~_�a«a{r­r|¢��y_{�h*iA{@u�s±®>©�prªE«9¯�y_{¾u�egi+ÂÃ{@uwi6��{gi6u ¢Ê@B��S»XÂOu�|�s�swegy4´1{�|�{ �Ê_Ê �auwe�~Uu�|¢{&~/�N�wyNzg�x�yNh*h2zg{g|}x6~Uuw|�y_{+svi6uvu�|¢{g�P°Uu�egic�Fi6��x�i6{@u�~U�_i1y_¿FzPsviA�¢iHswsc®Ëy_���������*���#��&�� ��¯-|�{t¿ÀyN�wh+~4u�|¢yN{��wiHx�i6|�­_iH ¡rq±iA~Nx�e$��~_�vu�|�x6|¢�P~U{@u�|�{�x6�wiH~_swiAs�´1|·u�eXu�egi�{rzgh�¡Fi6�1y_¿- g~Uu�~2Ü�y4´cs ~U{P ±u�egi�{rzgh�¡Fi6�1y_¿�z�swi6��s6»d eg|}s�|�s+{�yUu±svz��w�g��|}sv|�{g��sw|�{�x�i£´1|¢uweg|�{½~�ªE«c°aiH~_x�eI�P~U�wuw|}x�|���~U{@u±sv|�h�z��·u�~U{giAy_z�sw�¢q�|�{@uwiA��~Nx!u�s´1|·u�e+y_{g��q�~��¢|�h�|·u�iA +swi�u�y_¿Fy_uwegiA�a��~U�wuw|}x�|���~_{Nu�s6»�d egicswzg�Fi6�wÜ�zgy_zPsÅ|¢{g¿Ày_��h�~Uuw|�y_{���i6�g��iAswi6{@u�sÅ~x�y@s�u�|�{�uwiA�wh+sÅy_¿�{gi�u�´�y_��Ä�¡�~_{� t´1|} ruweÁ°@��y_ztu�i6��sÅ¡gztÍ\i6�9yrxAx�zg�P~4uw|�y_{+~_{� �i6{� t¸Segy@s�ua��iAswy_z���x6iAsA°~U{� /|}s h+~U|�{g�¢q$�wiHsv�Fy_{Psv|�¡g��i¨¿ÀyN� uwegi� tiA�_��~_ g~Uuw|�y_{$yU¿��Fi6�w¿Ày_��h+~U{�x6i�|¢{Z©�ptª¨« � s6»

ß � é�n�o�p�q�r

Page 13: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

ÊH� � ����( �"�� ����^� �*� �^���

�Î\Ï\ЬÑ�¦I|�h*���¢iAh*iA{@u�s±~�uw��~U{�sw�Fy_�wuv¸O��~LqNi6��ºP�·u�i6��|¢{g��h�iAx�eP~U{g|}svh ´1|·u�eÉh2zg�·u�|¢���¢iÌ~_�_i6{@u�s�u�e�~4u~U���¢y4´csmu�y£º��¢uwi6��y_ztu�swzg�PiA�vÜPzgy_z�s�uw��~4Ô±x*¡Pi6¿Ày_��i+|·u���iA~Nx�egiAsEuwe�i±i6{� t¸Segy@s�uH»±d eg|}s�~U�g���wy@~_x�e|¢{r­Ny_��­_iAs2u�egiÌ tqr{�~Uh�|}x/��~U�wuw|¢uw|�y_{g|�{g��yU¿EuwegiZªE« |¢{@uwy�sw��~4u�|�~_�c~U��iA~Ns*xA~U���¢iH  ������ �*~_{� Éuwegi~_s�svytx6|�~Uuw|�y_{±y_¿ÁuwegiHsvi�x6i6����s�´1|¢uwe/h�zg�¢uw|}x6~Ns�u �_��y_zg�Ps6»�d egim¡�~_sw|�xE|} tiA~2|�s9u�y� gq@{P~Uh�|�xA~U���¢q���~_�v¸uw|¢uw|�y_{$uwegi�ªE«É|�{@uwy+x�iA�¢�}s�yU¿� t|¢Í\i6��i6{@ucsv|�Ò6iHs6°t tiA�PiA{� t|�{g��y_{±u�egi� ti6{Psv|¢u�q+yU¿-��~U�wuw|}x�|���~U{@u�s��Fi6�x�iA�¢�S°@uwegim{rzgh�¡Fi6� yU¿¬~L­4~_|¢�}~U¡g��i¨h2zg�¢uw|}x6~_svu9�N�wyNzg��sA°@~_{� �u�egiE��|�{gÄ+¡�~U{P t´1|� tuwe$~_{� ±���wytx�iHswsw|�{g��wiHsvyNzg��x�iAs ~L­4~U|��}~U¡g��iE�Fi6�1�P~U�wuw|}x�|���~U{@uA»

�)��� � � � � � !%*"(��@� !�&-*,(���� � � * ��(�&�Å~_�vu�|�x6|¢��~_{@u�saeP~L­_ic��|¢h�|¢uwiH ±{gi6u�´9yN�wÄ�~U{� /j9� Y ���wytx�iHswsw|�{g��x�qtx���iAs9��iAswy_zg��x�iHs6»�ÂO¿�uwegim��~U�wuw|}x�|���~_{Nu � s~_�wiH~+yU¿a|�{@uwiA�wiHs�um|�s�swyX�}~U���_i�u�e�~4umuwegi2uw��~4Ô±x�egi���iAx6i6|�­_iAsmx6~_{g{gy_uE¡Fi2�g��ytx�iHswswiA £|�{���iA~_�Áuw|�h�i_°�{gyh�iHx�e�~U{g|}swh x�y_z��� Xi6{�~_¡g�¢i�eg|�h u�y2��iAx6i6|�­_i�~U���Pu�egi� g~4u�~�e�im|}s |�{Nu�i6��iAsvuwiH ±|�{Á»ÅÂÃ{� tiAiA �°t|�{Xu�eg|}s1x6~_swi_°iA­_iA{+|·¿Áu�egi�x�i6���}s�egimsvz�¡�swx6�w|�¡FiA +i6¶t~Nx!u��¢q*h+~4u�x�eXeg|�s�~U��iA~�yU¿Á|�{Nu�i6��iAsvuA°Nuwegim��iAx�iA|¢­NiA *u���~UÔ+x¨i�¶gx�iAiA gse�|�s�xA~U��~Nx�|¢u�q_» ��y_��uwe�|�s��gzg���Py@sviN°�~/z�swi6��s�~4u�|�sv¿Ë~_x�uw|�y_{¾h*i6uw��|�x�|}s�z�swiA �uwy£u�~UÄNi+|¢{@uwyZ~Nx6x�yNzg{@u�uwegi���wyN�PyN�vu�|¢yN{ZyU¿a|�{Nu�i6��iAsvuw|�{g�$ �~4u�~±��~Uuwi���iAx6i6|�­_iH Z~U{� Z���wytx�iHswswiA Á°F~_{� Zeg|}s�x6~U�P~_x�|¢u�q£x�y_����iAsw�PyN{� t|�{g�u�y�uwegi�h�~U¶t|¢h2zgh  g~Uu�~���~4u�i�uwe�~Uu¨egi�xA~U{£e�~U{P t�¢i±®Ë�¢|�h�|·u�iA Z¡rq$eg|�s¨{gi�u�´�y_��ÄXx6y_{g{giHx!u�|¢­r|¢u�q$~U{P ��LyN����wytx�iHswsw|�{g�±�Fy4´9iA��¯�»¨¼½egiA{�~±�P~U�wuw|}x�|���~U{@u¨��iAx6i6|�­_iAsE~U{� Ì�g�wytx6iAs�sviHs¨~U����uwegi� g~4u�~±egi2|�sE|�{Nu�i6��iAsvuwiH |�{Á°reg|}s9s�~4u�|�sv¿Ë~_x�uw|�y_{+h�i�u��w|}xc|}s9h�~U¶t|¢h+~U�F´1e�~Uuwi6­Ni6��uwegimsvzg�Fi6�wÜ�zgyNz�s�uw��~4Ô±x1��~4uwiN»-¹¨i6��i_°@uwe�i¨�_y@~U�P|�s{�yUu¨u�y/~N g~U�gu¨uwy$uwe�i2´�y_��s�uE�wiHx�i6|�­_iA�¨|�{Ìu�i6��h�smy_¿a{gi�u�´�y_��Ä/x6y_{g{�iAx!u�|¢­r|¢u�qÌ~U{� Ì�g�wytx6iAs�sv|�{g�±�Fy4´9iA�A°¡�ztu1uwy�h+~4¶t|�h*|�Ò6i�u�egi�s�~4uw|}sv¿Ë~_x!u�|¢yN{Xy_¿�u�egi��wiHx�iA|¢­Ni6��´1|·u�e£uwegi���y4´9iHs�u z�swi6�cs�~4u�|�sv¿Ë~_x�uw|�y_{/­L~_�¢z�i_»�)��� � ����� *��5�"����� ����� (�� (�# ( *�ÂÃ{^Î�ÏFÐ�Ñ�¦\° �%���"��;��~_�wiX�g�wytx6iAs�sviHsmuwe�~Uu2��zg{&~4u� t|·Í\i6��i6{@u��P~U�wu�s�y_¿ uwegi${gi�u�´�y_��Ä\»£d e�i6q�~U��i+{gyUuswi6��­_iA��sA°H|¢{�uwegi1swi6{�swiau�egi6q� gy¨{gy_u�~_|¢hµ~Uu-�g��ytx�iHswsw|¢{��E~U{rq��_��y_¡P~U�rs�u�~4uwi9¿Ày_��uwe�i�ªE«c°Uswycuwe�i6q� tym{gyUu��iAx6i6|�­_i1 g~Uu�~�u���~UÔ+x1swi6{@u�¡Fi�u�´�i6iA{���~U�wuw|}x�|���~U{@u�s6»�Æ1x!u�z�~U���¢qN°N~_�_i6{@u�sa tqr{�~Uh�|}x6~_�¢��q2 ti6uwiA�wh�|�{gicÒ6yN{giAs´1|¢uwe£u�egi�ªE«(¡rq/x6y_{�sw|� gi6��|¢{g�*u�egi� t|}s�u��w|�¡gztu�|¢yN{ZyU¿Å��~_�vu�|�x6|¢��~_{@u�sc~_{� /uwegiAq/xA~U�}x�zg�}~4u�i�~U�g���wyN�g�w|}~4u�ix6i6���·¸Ãsw|¢ÒAiAs�~_x6x6y_�� t|�{g��u�y2u�egi� ti6{Psv|¢u�q+yU¿-��~U�wuw|}x�|���~U{@u�s9|�{/iA~_x�eXÒ6y_{�i_»ÅÆc�Ni6{@u�s1~_��swy�e�~L­Ni¨u�y2�Fi6��|�yr g|·¸xA~U���¢q����wytx�iHsws¬uwe�i s�~4u�|�sv¿Ë~_x�uw|�y_{�y_¿PiH~_x�e���~_�vu�|�x6|¢�P~U{@u�~Nx6x6y_�� t|¢{��1uwy�eg|}s�x6~U�P~_x�|¢u�q_°Lu�egi1sv|�Ò6i�yU¿Peg|�s�~_�wiH~y_¿�|¢{@uwiA�wiHs�u�~U{� *u�egiE tiA{�sw|·u�q*yU¿Á��~_�vu�|�x6|¢�P~U{@u�sÅ´1|¢uwe�|¢{±e�|�s�x�zg����i6{@uaÒ6yN{gi_»akE{�x�icuweg|}s9x6y_h��gztu�~4u�|¢yN{+|�s gy_{giN°g~U�_iA{@u�s�x6~U{£ ti6uwi6��h�|¢{�iE{giA´ ÒAy_{giHsm®Ëy_�1|�{r­_i6��swi6��q2u�egi6q$x6~U{/~U�N�_��i6�N~Uuwici6¶t|�svuw|�{g��Ò6yN{giAs�¯!°t~U{P h�yt t|¢¿Àq�u�egi¨x6i6���·¸Ãsv|�Ò6iHsÅ´1|¢uweg|�{+uwe�icÒ6yN{giAs�´1egi6��i uwegi¨��~U�wuw|}x�|���~U{@u�sÅ´1|·u�e+uwe�ic�¢y4´�iAsvu�s�~4uw|}sv¿Ë~_x!u�|¢yN{+~U��i��ytx6~UuwiA Á»-d egiA�wi6¿Ày_��i_°rÎ\Ï\Ð�Ñ�¦���iA�@zg|���iAs�uwegic gq@{P~Uh�|�x���~_�vu�|·u�|¢yN{g|�{g��yU¿�u�egi1ª¨«�|�{@uwy�x�iA�¢�}sÅyU¿\ t|¢ÍFiA�wiA{Nusw|�Ò6iAsA°�~_{� /uwegi2~_s�svytx�|}~4u�|¢yN{$y_¿�uwegiHsvi�x6i6����s¨´1|·u�eZh�zg�¢uw|}x6~Ns�uE�_��y_zg��sA»9ƨ�_iA{Nu�s1e�~L­Ni�uwyX tqr{�~_h�|�xA~U���¢q gi�uwiA�wh�|�{gi�~U�g���wyN�g�w|}~4u�imx6i6���·¸Ãsw|¢ÒAim­4~_�¢zgiHs |¢{£yN�� tiA��uwy+h+~4¶t|�h*|�Ò6i�z�swi6��s��rs�~4u�|�sv¿Ë~_x�uw|�y_{Á»³Ezg��|¢{g��u�egi�swiAs�sv|�y_{Á°t~_�_i6{@u�s9�Fi6�w¿Ày_��h u�egim¿Ày_���¢y4´1|�{g��y_�Fi6��~4u�|¢yN{�s ���Å~U�wuw|¢uw|�y_{Ìu�egi�ª¨« |¢{@u�y$swi6­_iA��~_��1&�"!� ��°Á~Nx6x6y_�� t|¢{��+uwy$uwegi+ t|}svuw��|¢¡gzguw|�y_{�y_¿�z�swi6��s6°Fu�egi�z�sviA��ssw~Uuw|}s�¿Ë~Nx!u�|¢yN{�s6°g~_{� Xuwegi�ªE«(s�u��wz�x�uwzg��i+®ÀiN» �P»¢°t��yry_h+s6°r´ ~U����sA°ti�u�xU»ë¯!»

�j9y_h��gztu�i�uwegi�~_�g�g��y_�g��|}~4uwi�x�iA�¢�¢¸Ãsv|�Ò6iE¿Ày_�ciH~_x�e$Ò6y_{�i�®>sviAi �-|¢�Nzg�wi��r¯!»

�³¨|�­r|� gi¨iA~Nx�e+Ò6yN{gic|�{Nu�y�x�iA�¢�}sA°@~Nx6x�yN�� g|¢{g��u�y�eg|}s�x6y_h��gztu�iA ±x6i6���·¸Ãsw|¢ÒAi_°N~_{� ±~Nswsw|¢�N{+~�h�zg�¢uw|}x6~Ns�u�_��y_zg�£~_ � t�wiHsws9u�y*iH~_x�e£x�iA�¢�Áy_¿�iH~_x�e/Ò6y_{�i_»

ÝÀÞ-ßÁÝáà

Page 14: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� ÊNÊ

�ÂÃ{t¿Ày_��h u�egi ��~U�wuw|}x�|���~U{@u�s�y_¿P´1eg|}x�e*h�zg�¢uw|}x6~Ns�uÅ�_��y_z���s�uwegiAq�{gi6iH �u�y���y_|�{2|�{2yN�� gi6�-uwy�|�{Nu�i6��~_x�u´1|·u�e£��~U�wuw|}x�|���~U{@u�s �¢ytx6~UuwiH $~_�wyNzg{� XuwegiAh/»

Superfluous Area Area of Interest

Cells

��|��_z��wi�� ���Å~U�wuw|¢uw|�y_{�|¢{g��´1|¢uweZ t|¢ÍFiA�wiA{@u¨x�i6���¢¸Osw|¢ÒAiAs

d egiEº���s�u�uwe��wiAi¨y_�Fi6��~4u�|¢yN{�s�~U��iEx6~_�¢��iA +uwegi ()��� ����"G�c�^� �G&^����� �_(*°g´1egiA�wiH~_s�uwegim�wiHsvz��·u�s�y_¿ÁuwegiHsviyN�PiA��~Uuw|�y_{�s ~Ns1 tiAsw|¢�N{�~4u�iA /~_s�u�egi)( � � ����"G�c��"��*&���( ����� &�"�»�)�;� � ! � � (%��� (���� ��� � ! *"(����ÂÃ{¾y_�� tiA�Eu�yÌx�yNh*h2zg{g|}x6~Uuwi*h�~_�g�g|�{g�£|¢{g¿Ày_��h�~Uuw|�y_{�uwy£z�swi6��s6°¬|>» i_»�°Áu�egi+~_s�svytx�|}~4u�|¢yN{�¡Fi�u�´�i6iA{¾x6i6����s~_{� Éh�zg�¢uw|}x6~Ns�u+�_��y_z��É~_ � t�wiHswswiAsA°a|¢u±|�s�{�iAx�iHsws�~U��q�uwy¾º�{P  ~¾´ ~Lq�uwy�|} ti6{@uw|¢¿ÀqÉ~_{� É{�~Uh�i/uwegiHsvix6i6����s�´1|·u�eg|¢{�u�egi±ªE«c» �-|���svuA°¬uwegi±ªE« |�s�s�u�~4uw|}x6~_�¢��q��P~U�wuw|¢uw|�y_{giH �|�{@uwyÌswi6­Ni6��~U����~_�w�Ni���~U�wu�sA°�xA~U���¢iH ��� �^����� 1&^"!� �!»Ìd egiAswi$svu�~_�vuw¸SÒAy_{giHs�~U��i±~_x�uwz�~_�¢��q� ti�º�{�iA &~Nx6x�yN�� g|¢{g�£u�yÌu�egiX|�{@uw��|¢{�sw|}x±s�u��wzPx!uwz��wi±y_¿u�egiZª¨« ®Ëi_» ��»�°9��yry_h+s6°aÜ�yry_�H°�´ ~U����sA°�i6u�xU»ë¯ ~U{�  x6~_{(� u±i6­_iA��¡PiÌx6y_h�¡�|¢{giH �»^«�~_x�e^svu�~U�wuv¸OÒ6yN{gi/|�ssvu�~Uuw|}x6~_�¢��qÌ��~_�vu�|·u�|¢yN{giA �|¢{@u�y/|�{� t|�­r|�sw|�¡g�¢i 1&�"!��� � "����;�¨´1eg|}x�e¾~_�wi*uwe�i±svh+~U����iAsvu�z�{g|·u�~U��qÌÒ6yN{giAsmu�e�~4ux6y_h��FyNswiEu�egi�svu�~_�vuw¸SÒAy_{giN»a³¨zg��|�{g��uwegi2sviHswsw|¢yN{Á°gsvu�~U�wuv¸OÒ6yN{giAs1~_�wi� tqr{�~_h�|�xA~U���¢qX g|¢­r|} tiA £|�{@uwy+Ò6yN{giAs´1e�|�x�eZ~U���Áe�~L­Nimuwegi�s�~Uh�i�x�iA�¢��sv|�Ò6iN»9pry�°Px�i6���}sc~U��i�h+~U�g�g|�{g��yU¿Åh2zg�·u�|�xA~_svuc�_��y_zg�Ps�u�y±~�{rzgh�¡Fi6�cy_¿ÒAy_{gi6¸Sz�{g|·u�s6»2ƨs�~U�Ni6{@u�sm tiAx6|� gi2u�y/ gi�º�{gi�{giA´µÒ6yN{giAsm|�{�yN�� tiA�¨u�y/u�~UÄNi�|�{@uwy£~_x6x6y_zg{@u�x�e�~U{��_iAsE|�{u�egi� t|}s�u��w|�¡gztu�|¢yN{£yU¿���~U�wuw|}x�|���~U{@u�s6°ru�egi6q$|� tiA{@uw|¢¿ÀqXu�egiAswi�Ò6yN{giAs1~Ns1svi6u�s1y_¿-yN{gi�y_�1h�y_��i�x�y_{@u�|¢�Nzgy_z�sÒAy_{gi6¸Sz�{g|·u�s ¡PiA�¢yN{g�_|�{g�*uwy*u�egi�sw~_h�i�svu�~_�vuw¸SÒAy_{giN»

ß � é�n�o�p�q�r

Page 15: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

ÊL� � ����( �"�� ����^� �*� �^���

d�y*swzgh�h+~U��|¢ÒAi_°t~*Ò6yN{giE|}s ~2swzg¡�swi�u1y_¿�~2svu�~_�vuw¸SÒAy_{gim~U{� $|}s�x6y_h��FyNswiA ±¡rqnx�y_{@u�|¢�Nzgy_z�s9Ò6yN{gi�¸

z�{g|·u�s(n ≥ 1)

»�¼½|·u�eg|¢{/~��N|¢­Ni6{±ÒAy_{giN°@~_�¢��x6i6����s9e�~L­_icuwegi�sw~_h�imsw|¢ÒAi¨¡gztu�u�´�y2 t|}s�u�|¢{Px!u Ò6y_{�iAs�x�y_z��� eP~L­_i� t|·Í\i6��i6{@u¨x6i6���·¸Ãsv|�Ò6iHs6»�)��� �9! �,*"(�& (��)! � *8����*���� � � ����*5&�� � � .�)( & ! *"(����d e�i6��i�~_�wi�swi6­_iA��~_�\�¢iA­_i6�}s yU¿�x�yNh*h2zg{g|}x6~Uuw|�y_{/|¢{¾Î\Ï\Ð�Ñ�¦ �

�«�~_x�e¾��~_�vu�|�x6|¢��~_{@umswzg¡�s�x���|¢¡FiAsEuwy£yN{gi2yN��h*yN�wi2h�zg�¢uw|}x6~Ns�u��N�wyNzg��sE¡gztu�sviA{� gs� g~Uu�~$��~_x�ÄNi�u�sy_{Z~�sv|�{g�N�¢i��_��y_z��Á»

�«�~_x�e£��~_�vu�|�x6|¢�P~U{@u�|}scx6y_{g{giHx!u�iA Xuwy±~�sv|�{g�N�¢i�~U�Ni6{@uA°tzPsv|�{g�+~ Y¨³E�½zg{g|}x6~_svucx�yN{g{giAx�uw|�y_{Á»

�Æc�Ni6{@u�s�x�yNh*h2zg{g|}x6~Uuwic´1|¢uwe±iH~_x�e+y_uwegiA��y_{±~2sv|�{g�N�¢ich2zg�¢uw|}x6~_svu��N�wyNzg� ��uwegi�� �G�*"���� � � ��� ���2���� �'&^����®

AMG¯!»

Æ���~_�vu�|�x6|¢�P~U{@u1e�~_s�u�y�swzg¡�s�x���|�¡Pi�u�y2u�´�y+ t|¢ÍFiA�wiA{Nu1Är|�{� gs1y_¿�h�z��·u�|�xA~_svuc�_��y_zg��s ��� ��� � ���'&������+~_s�svytx6|�~UuwiA &uwy�u�egiÌx�iA�¢�}s�uweP~4u±|�{Nu�i6��sviHx!u+eg|}s±~U��iA~�yU¿�|�{Nu�i6��iAsvuA»(ǨyUuwi£u�e�~4uX~��~U�wuw|}x�|���~_{Nu1yN{g�¢q$sviA{� gs1 g~Uu�~*uwy*u�egi�h�zg�¢uw|}x6~Ns�u1�N�wyNzg�/~Nswswytx�|}~4u�iA +u�y�eg|�s¨x�zg���wiA{@u1x6i6���>»

���&^"�� �'&�� ���'&�������~_s�svytx�|}~4u�iA &uwy¾uwegi ��� �^����� %&�"!� ��uweP~4u±|�{Nu�i6��sviHx!u+eg|}s+~U��iA~�yU¿m|¢{@uwiA�wiHs�uH» �gy_�uwegiHsvi¾�_��y_z���s6°c~I��~U�wuw|}x�|���~_{Nu/|�s$y_{��¢q½~&��iAx6i6|�­_iA�A» Æc�_iA{@u�s$z�svi¾x�yN{Nu��wyN�E�N�wyNzg��s±uwyÉswi6{P h+~U�g�g|�{g��|�{t¿Ày_��h+~4uw|�y_{/��i6�}~4uw|�­_iEuwy*u�egi�s�u�~U�wu1Ò6y_{�iAsA»�d e�|�s |�{t¿Ày_��h+~4u�|¢yN{X|}s1�PiA�w|�yt t|}x6~U����q±sviA{Nu¿Ày_�miA~Nx�eÌs�u�~U�wuv¸OÒ6y_{�i_°P~_{� Ìx6y_{@u�~_|¢{Zu�egi�h+~_�g�g|�{g�X|�{t¿Ày_��h+~4u�|¢yN{£¿Ày_��~U���¬u�egi�ÒAy_{giHs¨¡Fi6��y_{g�N|¢{��uwyXuwegi�svu�~_�vuw¸SÒAy_{gi±®Ë|>» i_»�°Fuwegi*x�iA�¢�¢¸Osw|�Ò6i�¿Ày_�EiA~Nx�eZÒ6y_{�i�~U{� /u�egi2~Nswswytx�|}~4u�iA /h�zg�¢uw|}x6~Ns�uE�_��y_zg��s~_ g g�wiHswswiAs�¯!»

��y_��iH~_x�e�yU¿ u�egiAswi±�_��y_z���s6°�uwe�i±��~U�wuw|}x�|���~_{Nu�eP~_s�u�yÌh+~UÄNi+iA~U����q&^��"@s�u�~UÄr|�{g�Z|¢{@u�y�~_xAx�y_z�{Nu�e�|�ssw�Fi6iA Á°�~U{� Xuwe�i ��y_|�{t¸S�}~4u�i6{�x6q±­4~U��zgi_»«�~Nx�eZ��~U�wuw|}x�|���~_{NuE|�sEx�y_{�{giAx�uwiA /u�y±eg|}s¨{�iA~U��iAsvu¨~U�Ni6{@ucz�sw|¢{��X~ Y¨³E� x6y_{g{�iAx!u�|¢yN{Á» «�~_x�e£u�|¢h�i

~±��~U�wuw|}x�|���~U{@u¨iA{@uwi6��s¨~X{gi6´ ÒAy_{gi6¸Sz�{g|·uH°Pe�i2swi6{� gsE~Xswegy_�wu¨h�iAs�s�~U�_i�u�yXeg|}sm~U�_iA{@uA»¨d eg|}sch�iHsws�~U�Nix6y_{@u�~_|¢{PsEe�|�s�|} tiA{Nu�|·u�qN°¬eg|}s��FyNsw|·u�|¢yN{�|¢{¾uwe�i+Ò6y_{�i�¸Ozg{g|¢uA°Áeg|}s�x6zg�w��i6{@u�sw|¢ÒAi*y_¿ ~_�wiH~Xy_¿�|�{@uwiA�wiHs�u�~U{P e�|�s�x6~_��~_x6|·u�q9 �Ê6��O»Åd egi6��i�¿ÀyN�wiciH~_x�eX~_�_iA{Nu9|�s ~U¡��¢i¨uwy�u���~Nx�Ä�u�egim�¢ytx6~Uuw|�y_{±y_¿Á|·u�s x�y_{�{giAx�uwiA ±z�sviA��s9|�{u�egi�ªE«c»PÂÃ{�y_�� ti6�1u�y±i6­4~_�¢z�~Uuwi�u�egi2 tiA{�sw|·u�q/yU¿Å��~_�vu�|�x6|¢��~_{@u�s1´1|¢uweg|�{ÌiH~_x�e£Ò6yN{gi_°F~U�_iA{@u�s1i6¶tx�eP~U{g�Ni|�{t¿ÀyN�wh+~4u�|¢yN{$yN{Xu�egi

AMGh�zg�¢uw|}x6~Ns�u1�N�wyNzg�Á»

�)��� � ! � � (%���1!�#�� � ��( *"' �ƨ�_iA{Nu�s±|�h��g�¢iAh�i6{@u£~&h�~_�g�g|�{g�É~_�¢�Ny_��|·u�egh u�yÉ tqr{�~_h�|�xA~U���¢q^ ti�ºP{gi�ÒAy_{giHs±|�{½uwegi¾ª¨«¨°�~_{� ^uwy gq@{P~Uh�|�xA~U���¢q�x�yNh��gztuwi�~U{$~U�g�g��y_���w|}~4u�icx�i6���¢¸Osw|¢ÒAi¨´1|¢uweg|�{XiH~_x�e+ÒAy_{giN°@x6y_{�sw|� gi6��|¢{g��uwegi� t|}s�u��w|�¡gztu�|¢yN{y_¿P��~_�vu�|�x6|¢�P~U{@u�sÅ~_{� �u�egi6|��as�~4uw|}sv¿Ë~_x!u�|¢yN{�sA»�d�y�sw|�h*���¢|¢¿Àq�u�egicx�yNh*��ztu�~Uuw|�y_{*yU¿\h�~_�g�g|�{g��|¢{g¿Ày_��h�~Uuw|�y_{Á°Î�ÏFÐ�Ñ�¦�y_{g��q�x�yN{�sv|} tiA��s�s��NzP~U��i�x6i6����sA°U´1|¢uwe+~U{2|¢{@uwiA�_iA�-{rzgh2¡PiA�ÅyU¿\x�i6���}s��PiA�ÅÒ6y_{�i_»�d eg�wyNzg�_e�y_ztu-uwegiswiAs�sw|¢yN{Á°U~U�Ni6{@u�s��Fi6��|¢yt t|}x6~_�¢��q�x6y_h��gztu�i uwegic~L­Ni6��~U�_i� ti6{Psv|¢u�q�yU¿\��~_�vu�|�x6|¢��~_{@u�s��Fi6�Åh�z��·u�|�xA~_svua�_��y_zg�Á°¡rq� t|�­@|} t|�{g�Zu�egi±{rzgh�¡Fi6�2yU¿¨x6y_{g{giHx!u�iA ���~_�vu�|�x6|¢��~_{@u�s�´1|¢uwe�u�egiX{rzgh2¡PiA��yU¿c~L­4~U|��}~U¡g��i+h�zg�¢uw|}x6~Ns�u�N�wyNzg��s�¿Ày_�9uwegi�~_�g�g��|�xA~4uw|�y_{¬»-ÆEs ��~U�wuw|}x�|���~U{@u�s9~_�w��|¢­Ni¨~U{P ±h�y4­_iE|¢{$uwegimª¨«¨°g~U�_iA{@u�s9Ä_i6iA�±u���~Nx�Ä*y_¿u�egi� tiA{�sv|¢u�q±y_¿-��~_�vu�|�x6|¢�P~U{@u�s�|�{/iH~_x�e/Ò6yN{gi_»d egi�h+~_�g�g|�{g�+~U���_y_��|¢uwegh x6y_{�sw|�svu�s |�{/uwegi�¿ÀyN�¢��y4´1|�{g�2yN�PiA��~Uuw|�y_{�s �

ÝÀÞ-ßÁÝáà

Page 16: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� ÊH²

��-|¢��s�uH°P~_�_i6{@u�scx�yNh*��ztuwi�~±x6i6���·¸Ãsw|¢ÒAi�¿Ày_�ciH~_x�e/Ò6y_{�i�¡rqXy_{��¢qXu�~UÄr|�{g�+|�{Nu�yX~_xAx�yNzg{@u�u�egi� t|}svuw��|·¸¡gztu�|¢yN{/y_¿-�P~U�wuw|}x�|���~U{@u�s�|�{/uwegi�ªE«c»

�d egi6{¬°\uwegi*��~U�wuw|}x�|���~_{Nu�sc´1|¢uwe�uwegi*�¢y4´�iAsvuEs�~4u�|�sv¿Ë~_x�uw|�y_{�~_�wi�|} tiA{Nu�|·ºPiA �~Ns¨´�i6����~_s¨uwegiA|¢�� t|}s�¸uw��|¢¡�ztuw|�y_{±|�{+u�egiEªE«c»@ÂO¿�~U�Ni6{@u�sa gi�uwiHx!u ~�x�yN{�x�iA{@uw��~4uw|�y_{�y_¿Ázg{�s�~4uw|}svº�iA +�P~U�wuw|}x�|���~U{@u�sa´1|·u�eg|¢{~¾��~U�wu+yU¿�~�ÒAy_{giN°au�eg|�s±Ò6y_{�i/|}s+ t|�­r|� tiH  |¢{@uwy¾u�´�y�{gi6´ Ò6yN{giAs*|�{ yN�� gi6�*uwy�|}svyN��~Uuwi/uwegiHsvi��~U�wuw|}x�|���~_{Nu�s6»

��-|¢{�~_�¢��q_°1~_�_i6{@u�s*xA~U{½ tiHx�|} ti£¿À�wyNh5uw|�h�i£uwy�u�|¢h�i£uwy&~_�_�N�wiA�N~4u�i$x6y_{@uw|��_zgyNz�s�Ò6yN{giAsA°�|¢¿�uwegix�iA�¢�¢¸Osw|�Ò6iAs1~_�wiEuwe�i�sw~_h*im¿ÀyN� uwegiHsvi�ÒAy_{giHs1~U{� $|·¿-uwe�i6qX¡Fi6��y_{��2u�y�uwegi�s�~Uh�i�s�u�~U�wuv¸OÒ6yN{gi_»

� %�� ���6.01'2"������ ��¬#/��" ������ � � * �.� ��� )��� & ��( �)*"(���� ! �� � � ! � .�"�� ��� *5*�����#%�d e�i*¤2¥w¦r§�¦�~U���g�¢|}x6~Uuw|�y_{�e�~_sm¡Fi6i6{�uwiHs�u�iA �y4­_iA�¨u�egi�ªEd1¹¨³ {�i�u�´�y_��Ä- ë�U²��c®ËªÅ��~_|¢h�i6{@u�d��wfHsm¹E~Uztu³��6¡�|·u!¯!»ÅªEd1¹E³�|�s ~�{�~4u�|¢yN{�~U�Feg|��_e$sw�Fi6iA X{gi�u�´�y_��Ä\°@ gi6�g��y4q_iH ±~U{� Xy_�Fi6��~4u�iA +¡rq �g��~U{�x6iEd�i6��iAx6y_h���³�°�´1|·u�e(u�egi�swzg�g�Fy_�wu$y_¿��cǨ��d�°1~U{½|�{g|¢uw|}~4uw|�­_i�yU¿�u�egi ���wiA{�x�e(lZ|�{g|}s�u�i6�/yU¿�ÂÃ{� tzPs�u��wq½~U{P �ciAswiA~U��x�eÁ»�d eg|}s2����~Uuv¿Ày_��h5|�{Nu�i6��x�yN{g{giAx�u�s*sv|¢uwiHs*|¢{r­_yN�¢­NiA �|�{É���³ ~Nx!u�|¢­r|¢uw|�iAs*´1|·u�eÉ~Nx6x�iHsws2��|¢{gÄts¿À��y_h8Ê :m¡g�Ps�zg�Iu�y&�t» B :m¡g�Ps6»^Æch�y_{��¾y_uwegiA��sA°�ªmd1¹¨³ ~_�¢��y4´cs2¿Ày_��i�¶t�Fi6��|¢h�i6{@u�~4uw|�y_{ ��i6�}~4uwiH u�y�ÂÃ� �L¼(³ml�°����wy_uwiAx�uw|�y_{ �4�wiHs�u�y_��~4u�|¢yN{�h*iHx�e�~U{�|�swh+s6°1j9y@pÉ~U{�  ª¨�9Ç �g�wy4­r|}sv|�y_{�|¢{g�P°aÂÃ�a­t�g° ~U{P lÌzg�·u�|�xA~_svuA»£d egiAswiAs�sviA�w­r|}x�iAs�~U��i�uwiAsvuwiH �´1|·u�e&Çci6¶@u :mi6{giA��~Uuw|�y_{�ÂÃ{@uwi6��{gi6u�~U�g�g��|}x6~4u�|¢yN{�s�swz�x�e&~_s¤2¥w¦r§-¦\°¨u�i6��i6h�iA giAx�|�{gi�~U�g���¢|}x6~Uuw|�y_{�sA°¨~U{P  :��1Â�³ x�yNh��gztuw|�{g�^~U�g���¢|}x6~Uuw|�y_{�sA» ªEd1¹¨³ swzg�g�Fy_�wu�sh2zg�¢uw|}x6~_svucsviA�w­r|}x�iHs9¡P~_swiA $y_{£¡Py_uweZÆEpgl�~_{� £pgptl�h�yr gi6�S»d egi�h+~_|¢{£|�{Nu�i6��iAsvu1yU¿�i�¶t�PiA�w|�h�i6{@uw|�{g�±¤2¥w¦r§�¦$´1|¢uweg|�{/uweg|}s1iA{@­r|��wyN{gh�i6{@u1|�s�u�e�~4uc|¢u¨|�{r­_y_��­_iHs9~

��yUu�y_¿�h2zg�¢uw|}x6~_svu�swy_zg��x�iHs �4�wiHx�i6|�­_iA��sA°F�wiA��~UuwiA �uwyZ{rzgh�iA�wyNz�s��_��y_zg�Ps6°Á|�{�sw|� giX~/­_i6��qÌeg|��_e�¡g|¢u���~4u�ih2zg�¢uw|}x6~_svu�i6{r­r|¢��y_{gh�iA{Num´1|·u�egy_zgum|�h���~_x�uw|�{g�${�i�u�´�y_��Ä/��zg{g{�|¢{g�/~U{� ��PiA�v¿ÀyN�wh+~_{�x�iHs6»�d egi*�_y@~U�-|�s~_��swycu�yE�@~U|�{2~E¡Pi6uvu�i6�ÅÄr{gy4´1��iA t�NiayU¿FÂÃ�¾lZz��·u�|�xA~_svuA°U~U{P �u�y¨u�iAsvu-iH�Nz�|¢�gh�iA{NuÅ|�{@uwi6��y_�Fi6��~U¡�|¢��|·u�q�|�{�sw|� ti~*h2zg�·u�|·¸O­_iA{� tyN��{�i�u�´�y_��ısvz�x�eZ~Ns9ªmd1¹¨³2»

��y_��u�egi�s�~UÄ_iÅy_¿Nu�egiAswiai6¶r�Fi6��|�h*iA{@u�sA°A´�ia´1��yUuwiÅ~c gzgh�h�q�¤�¥�¦r§�¦�x���|�i6{@uÁuweP~4u�~_�¢��y4´csFuwycsw|¢h2zg�}~4uwiu�egi����wiHsviA{�x�i2yU¿�~±�}~U���_i�{@z�h�¡Fi6�myU¿a��~_�vu�|�x6|¢��~_{@u�sA»Ed egiHsvi2��sviAz� ty_¸S��~_�vu�|�x6|¢�P~U{@u�s ¸1~U�}swy±Är{gy4´1{�~_sǨy_{/�a�}~Lq_i6�Ej9eP~U��~_x!u�i6��s�|�{/uwegi��@~Uh�iAs9u�i6��h*|�{gyN�¢yN�_q�¸9~_�wi� ti6��|�x�uwiA /yN{$ºP�_zg��i BÆEsX tiHswx6�w|�¡PiH  y_{ º��_z��wiZ�g°�u�eg|�sXi�¶t�Fi6��|¢h�i6{@u�~4uw|�y_{ |}s±sv|�h�z��·u�~U{giAy_z�sw�¢qÉ�wz�{ yN{½sviA­_i6��~U�1sw|·u�iAs

x6y_{g{�iAx!u�iA Xuwy+ªmd1¹¨³ ����d1���³µ©¬~_{g{g|�y_{Á°

�Â�Ǩ�1Â�Æ pry_�ge�|�~U¸Oƨ{Nu�|¢�Fy_��|}s

�Â�Ǩ�1Â�Æ �1ytx6�@zgi6{Px�y_z��vu

�«�ÇEpgd�¸ 9���i�u�~_�_{gi�|�{ 99��iAsvud egiAq�~U��i���ytx6~UuwiA �|¢{Psv|} ti�sviA��~U��~4u�i2~Uzguwy_{�y_h�y_z�smswqrsvuwiAh+s*®>ÆEpg¯�»ÁÂÃ{@uwiA�v¸ÃÆEpÌh�zg�¢uw|}x6~Ns�u�x�yN{tº��U¸

z���~Uuw|�y_{ e�~_s�¡Fi6iA{^swi�u�zg�^z�sw|¢{g�&l�pt³¨� �4l 9�:m� �Fi6i6��|�{g��¡Pi6u�´9iAi6{ uwegiÌ�c� � s±yU¿muwegi£¿ÀyNzg�XÆEp � s|�{r­_yN�¢­NiA �»d egi�¿ÀyN�¢��y4´1|�{g��u�~_swÄts ´9iA�wi��Fi6�w¿Ày_��h*iH X|�{£y_�� ti6��u�y�swi�u�zg�/uwegi�{�i�u�´�y_��Ä ��i6{�~_¡g��|¢{g�£��y_ztu�iAs�~N t­_iA�vu�|�swi6h�i6{@u�|�{�sv|} ti+l 9�:m� ®Àh2zg�¢uw|}x6~_svu�svyNzg��x�iAs�~_{� ¾�1���wyNztuwiA��s��g��i�¸ºg¶tiAs�¯!Ó

ß � é�n�o�p�q�r

Page 17: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

ÊA� � ����( �"�� ����^� �*� �^���

�-|¢�Nzg��i B��Åd egi�ª¨«^�Fy_�gzg�}~4u�iA /´1|¢uweZ tzgh�h�q$��~U�wuw|}x�|���~_{Nu�s

�-|��_zg��i����ad egi�ªEd1¹E³µ{gi6u�´9yN�wÄ

ÝÀÞ-ßÁÝáà

Page 18: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� Ê@B

�x�egiAx�Är|�{g�+l�pt³E�½~U{g{gyNzg{�x6iAs�º��¢uwiA�w|�{g��Ó

� ti�ºP{g|¢{��+h�zg�¢uw|}x6~Ns�u1¡Fy_zg{� �~U��|¢iHs6»

���wyNh ~£��y_ztu�|¢{g�£�Fy_|�{@u�yU¿ ­@|�i6´�°�l�pt³E� �Ul 9�:m�µsviHswsw|¢yN{�s�iAsvu�~_¡g��|�swegh�i6{@u�h�z�svu�¡Fi±x�egiAx�ÄNiA �»�-|��·u�i6��|¢{��¾|}s�svzgiHs�i6{�x6y_zg{@u�i6��iA É¡Pi6u�´9iAi6{^ t|·Í\i6��i6{@uXÆmpIeP~L­_i/¡PiAi6{½svyN�¢­NiA �»½lZz��·u�|�xA~_svu*ÜPy4´cs+~U��ix6y_���wiHx!u��¢qÉuw��~U{�sv¿Ài6����iA ^u�eg�wyNzg�_e ªEd1¹¨³ {�i�u�´�y_��ÄF» �aÂ�lZ¸Ãptl svu�~4u�iAs/x�yN�w��iAsw�PyN{� t|�{g��u�y ¤2¥w¦r§�¦h2zg�¢uw|}x6~_svu¬�N�wyNzg��s¬~_�wiax6�wiH~4u�iA �~U{P �h+~U|�{Nu�~U|�{giA �|�{�sw|� giauwe�i9x�yN�wiÅ��y_zguwi6��sÁ|�{�u�egi6|��¬h2zg�·u�|�xA~_svu���y_ztu�|¢{��u�~U¡g��iAsA»d egi$h�iA~_swzg��iAs�´�i6��i±h+~_ gi+uwe�~_{gÄts�u�y�~Ìx�yNzg�g��iXy_¿ ÂÃ�P~U{giAh�~Ì|¢��� i_ÊH�_�N�£��~_s�sv|�­_i�u���~UÔ±x+h�iA~4¸

swzg��i6h�i6{@u¨ tiA­r|�x6iAsc��ytx6~UuwiA £|�{£uwe�i�¡�~_x�Är¡Fy_{gi��wyNztuwiA��s1x6�¢y@svi�u�y+uwegi2¡PyN�� gi6�H» 9�i6|�{g�±�P~_s�sv|�­_iN°tuwegiHsvi gi6­r|�x6iAs� tyZ{�yUu�|¢{@u�i6�w¿Ài6��i+´1|·u�e�u�egi±~U���g�¢|}x6~Uuw|�y_{�uw��~4Ô±xUÓ�uwe�i6q��Fi6�w¿Ày_��ho¡�~Nsv|}x�|} ti6{@uw|¢ºPxA~4uw|�y_{�~U{P u�|¢h�|�{g��u�~_swÄrs�~U{� +swi6{� *u�egi¨x6y_���¢iHx!uwiH + g~4u�~muwy�~�x6i6{@uw��~U�PsviA�w­Ni6�c®ÀÂÃ�a¸S¡FyNs�s�¯Å�¢ytx6~UuwiH �|¢{�u�egic{gi6u�´9yN�wÄ¡P~_x�Ä+yUÔ±x6i_°ruweP~4u¨x�yNh��gztuwiHs uwe�im��iAswzg�¢uw|�{g��h�iA~_swzg��i6h�i6{@u�s6°t|�{�x���z� t|�{g�*uw��~4Ô±xm��~4uwi�~_{� X��yNs�s ��~4uw|�y�°yN{gi�¸O´ ~Lq*�}~4u�i6{�x6qX~U{P ���|¢uvu�i6�H»Æ1 g g|·u�|¢yN{g{�~U����q_°@¿Ày_���N~UuwegiA�w|�{g��|�{t¿ÀyN�wh+~4u�|¢yN{±y_{±uwegim¡PyN�� gi6��{gi�u�´�y_��Äts6°N´9i�x�egyNswi1u�y2��zg{+u�egiEÂÃ�

h2zg�¢uw|}x6~_svuclZy_{�|·u�y_�1{�~_h*iH $lÌzg�·u�|�l¾kmÇ �ÊAÈ�O°lZz��·u�|�l�kmÇ |}s9~�h*yN{g|¢uwy_��|�{g��uwyryN��u�e�~4u x�y_����iAx!u�s6°@y_���N~_{g|�Ò6iAs�~U{� ± g|�sw�g�}~Lqrs9~U����u�egi¨ÂÃ�Éh�zg�¢uw|}x6~Ns�u

u���~UÔ±xÌ�g��iAswi6{@u$~Uu$u�egi���ytx6~4u�|¢yN{(yU¿�u�egi�lZzg�¢uw|}l�kmÇ swi6��­_iA�A» ¼½eg|¢��i�lZzg�¢uw|}l�kmÇ |}s/~&�_iA{gi6��~U���zg�w�FyNswi�h2zg�·u�|�xA~_svuEh�y_{�|·u�y_��|¢{g�Xuwyry_�S°F|·u�|�sEiAsw�FiAx�|}~U����q$|�{@uwi6{P tiA ÌuwyXh�yN{g|·u�y_�mh�zg�¢uw|}x6~Ns�uEuw��~4Ô±x�yN{��ytx6~_�-{�i�u�´�y_��ÄÌsviA�_h�i6{@u�s�~_{� ¾svegyNzg�} �~Nswsw|�svu�~${�i�u�´�y_��ÄÌ~_ th�|�{g|�svuw��~4u�y_��|�{�h+~U{P~U�_|�{g�$uwegi�u���~UÔ±xyN{/~_{$ÂÃ{@u���~_{gi�uH»lZz��·u�|¢h�y_{*|}s�¡gzg|��·uÅy_{*~�x���|¢iA{Nu �4swi6��­_iA�¬¡�~Nsv|}s-´1eg|�x�e*~U���¢y4´cs¬uwe�i  �~4u�~mx�yN�¢��iAx�uwyN��s�®ËxA~U���¢iH 2swi6��­_iA��s�¯

u�y�¡Pi� t|}svu�~U{@u1¿À��y_h u�egi : YcÂ9¿À��y_{@u1i6{� £ t|}sv����~Lqts�®ËxA~U���¢iH /x6�¢|�i6{@u�s�¯�»¼½egiA{±u�egiEswi6��­_iA�a|�s�svu�~U�wuwiH �°r~�´1|�{� ty4´½�Fy_��s�zg�$~_{� ±swegy4´csÅu�egiE ti6uwiHx!uwiH +h�z��·u�|�xA~_svu�swiAs�sv|�y_{�s

|} tiA{Nu�|·ºPiA /¡rq±egyNsvu �4�PyN�vu1{rzgh2¡PiA�A°t|�{�x�yNh�|¢{g��¡rq@uwi�x�yNzg{@u¨~U{� /swiAs�sv|�y_{Xu�q@�Fi_»kE{�|�{g|·u�|�~_��svu�~U�wuwz��Á°U{gi6u�´9yN�wÄ�h�yN{g|·u�y_��|¢{��m tyriHsÅ{gyUuÅu�~UÄNi�����~Nx�i_ÓNy_{g��q�´1egiA{+~mx6�¢|�i6{@ua|}sÅ��iA�@zgiAsvuv¸

|�{g�� �~4u�~�´1|¢����u�x��\ tzgh��X¡FiEsvu�~_�vu�iA �°r~U{P �h�zg�¢uw|}x6~Ns�u9uw��~4Ô±x1h�y_{g|¢uwyN�wiH �»-¼½egi6{X~2x���|¢iA{@u�|�s9|�{g|·u�|�~_�¢��qsvu�~_�vu�iA �°�uwegiÌx6�¢|�i6{@u+h+~U|�{É´1|�{� ty4´  t|}sv�g�}~Lqts2uwegi£u�yUu�~_�1¡�~U{P t´1|� tuwe yrxAx�zg��|¢iH I¡rq�u�egiZh�zg�¢uw|}x6~Ns�uu���~UÔ±xm~_{� $�g�wy4­r|} tiAs ~*�_��~U��eg|�xA~U�Å®À��|¢i�x�e�~_�vu!¯9¡g�wiH~UÄt ty4´1{$yU¿-uwegi�u���~UÔ+xm¡rqX~_�g�g��|�xA~4uw|�y_{$u�qr�PiN»����� ��� �=� ��( � ��� * � & ���! ��(����«�{� r¸SuwyU¸Oi6{P �uwiHs�u�|¢{���e�~Ns�¡Fi6iA{É��iA~_�¢|�Ò6iH �|¢{Éy_�� ti6�2uwy�­L~_�¢|} g~Uuwi£¤�¥w¦t§�¦�h2zg�·u�|�xA~_svu*swyU¿áu�´ ~U��i+¿À��y_hiH~_x�e£sv|¢uwiN»Åd egi�¿Ày_���¢y4´1|�{g�*uwiHs�u�s e�~L­_im¡Fi6i6{£�Fi6�w¿Ày_��h�iA  �

�uwegi���~U�wuw|}x�|���~U{@u�s1x6~U{Zswi6i�iH~_x�e/yUuwe�i6�c~U���PiH~U�c|�{/uwegi��N��~_�geg|}xmi6{r­r|¢��y_{gh�iA{NuH°g~U{� £xA~U{Zx�yNh2¸h�zg{�|�xA~4uwi¾z�sw|¢{��Iu�i�¶ruwz�~_��h*iHsws�~U�NiAsA°1�g��y4­@|} tiH ^uwegiAq(~U��i���ytx6~4u�iA  |¢{ uwegi � h�iH t|¢z�h �_��~Lq$���~_{g�_iNÓ

�uwegiAq+x6~U{Xz�sviE�wiAh�yUuwiEx�y_{g¿Ài6��i6{�x6i�®Ë~_z� t|�y�~U{� ±­@|} tiAy@¯Å|¢¿�uwe�i6��iE~U��ic��ytx6~4u�iA �|�{+uwe�ims�~Uh�i¨x6i6���>Ó

�iA~Nx�e$¤2¥w¦r§�¦XegyNsvu1�wz�{�s�h�zg�¢uw|��g��i� gzgh�h�q±iAq_iAsA°tsvy�~_s9u�y�x6�wiH~4u�i¨h�z��·u�|�xA~_svu�u���~UÔ±x¨yN{$h+~U{rqh�zg�¢uw|}x6~Ns�uc�N�wyNzg��sAÓ

ß � é�n�o�p�q�r

Page 19: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

ÊH� � ����( �"�� ����^� �*� �^���

Æ1 g g|·u�|¢yN{g{�~U����q2´�i1�PiA�v¿ÀyN�wh�iH ��Eyrp2h*iH~_swzg��i6h�i6{@u�s¨®Ë tiA��~LqtsA°U��~_x�ÄNi�u�sÅ�¢y@swsA°���|¢uvu�i6�H°N��~4u�iH¯�»-Æ^¿ÀiA´sw|�h*���¢i*swx6i6{�~_�w|�yNs¨e�~L­_i�¡Fi6iA{� ti6º�{giH Z|¢{�y_�� ti6�¨uwy$¡Pi�~U¡g��i�u�y$x6y_���wiA��~Uuwi�u�egi2 g~Uu�~X�N~4u�egi6��iA £´1|¢uwe´�i6���¢¸O ti6º�{giH $~Nx!uw|�y_{Ps�¿À�wyNh uwegi��P~U�wuw|}x�|���~U{@u�sA°ri_» ��»

�´1egi�u�egi6�cuwegi���~_�vu�|�x6|¢�P~U{@u�s ~U��i��_��y_zg�FiA X|¢{/u�egi�sw~_h�i�x6i6���Áy_� e�~_{g�_|�{g�+~U��y_z�{� ±u�egi�´9yN�w�} �Ó

�´1egi�u�egi6��uwe�i6��i9~U��i� tz�h*h2q���~U�wuw|}x�|���~_{Nu�sÁ�g��iAswi6{@uH°L~_{� �|¢¿�svyE´1egi�u�egi6��uwe�i6q�~U��i�x�yN{�x�iA{@uw��~4uwiH |¢{Z~*�_|�­_iA{/~_�wiH~�yN�cswxA~4uwuwi6��iA Xuwe��wyNzg�_egyNztu�uwegi�´�y_���� ÁÓ

�´1egi�u�egi6�cuwegiA�wi�|}sc~�³1ª�Ü�y4´(ÜPy4´1|¢{g�*|�{$u�egi�¡�~Nx�Ä@¡Fy_{�i_»ÂÃ{�u�egia¿ÀyN�¢��y4´1|�{g�¨swiAx!u�|¢yN{�s�® Bt» ²c~U{P  Bt» �@¯\´�i�´1|����@x6y_h�h�i6{@uÁuwe�i���iAswzg�·u�sÁyN¡tu�~_|¢{giH �|�{�u�´9yEsv�FiAx6|·ºPx

��zg{�s1~_h�y_{g�2uwegi�´1e�y_��i�x6y_���¢iHx!u�|¢yN{$y_¿� g~Uu�~�»

ÝÀÞ-ßÁÝáà

Page 20: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� Ê^M

���;� ��� �=� ��( � ��� *�� � ( *"' !�.)(�� *,�"!�� &�-|���svucx�yN{�sv|} tiA�c~U{£~Uz� t|�y*Ü�y4´ swi6{@u1¡rqX~+¤2¥w¦r§�¦$��~_�vu�|�x6|¢��~_{@u |�{£©¬~U{�{g|¢yN{X¸�sviAiEºP�_zg��i Mr»¼¾iÌx6~_{I{gy_uw|}x�i/uwe�~Uu±�PiH~UÄts£® M�M4��h�s�y_¿m tiA��~LqN°9��» B���yU¿m��~_x�ÄNi�u��¢y@sws�~U{P ÉÈN��h+s�yU¿9��|·uwuwiA��¯

yN¡�swi6��­_iA �¿Ày_�a�cÆÅdIÜ�y4´&h+~4u�x�e2´1|¢uwe�h�y4­_iAh�i6{@u�s-|�{�sv|} ti ­r|¢�wuwzP~U�t´�y_���� 2~4ua�_� � ²N²g°4�_� � B_²E~_{� XÊH��� �_È�»Æ1x�uwz�~_�¢��q_°r´1egiA{$��iA~L­r|�{g��u�egi� ti6��~_�vu�zg��iEx�iA�¢�S°ruwe�im�P~U�wuw|}x�|���~U{@u�xA~U{(� u1x�y_h�h2zg{g|}x6~4u�im~_{rq@h�yN�wic´1|¢uwey_uwegiA��smsw|¢{�x6i�h2zg�·u�|�xA~_svum�N�wyNzg�Ze�~NsEx�e�~_{g�_iH �°\zg{g��iAs�s¨e�i2|}sm�¢ytx6~UuwiH Ìx���yNswi�u�y$~U{�yUuwe�i6�my_{gi* tzg��|¢{g�u�egyNswi�h�y4­_i6h�iA{Nu�s6»Åd egi�s�~Uh�i�¡PiAe�~L­r|¢yN�1x6~U{/¡Fi�{gyUu�|�x6iA $¿Ày_� C�EGF�h�zg�¢uw|}x6~Ns�u1ÜPy4´cs6»

�-|��_zg��i M �aǨi�u�´�y_��ıx�e�~U��~_x�uwi6��|}s�u�|�xAs9 tz��w|�{g�+~Uz� g|¢y+swiAs�sv|�y_{�s

ß � é�n�o�p�q�r

Page 21: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

ÊHÈ � ����( �"�� ����^� �*� �^���

����� ��� �=� ��( � ��� *�� � ( *"'�" # �(%�&� *,�"!��1&ÂO¿Å´�i�{gy4´ e�~L­_i�~���yry_ÄXyN{ �Ey@p$��iAswzg�·u�s ¿Ày_�E~±³1ª Ü�y4´�swi6{@u¨¡rq$~±pryN�geg|}~�uwiA�wh�|�{�~U�S°� tiA�g|}x!uwiH Z|�{ºP�_zg��i+Èg»±´�i+y_¡�swi6��­_i2uweP~4u�¡g|¢uv¸O��~Uuwi+|}s��@zg|¢uwi±x�yN{�svu�~U{@u±®Ë~_¡PyNztu*�_È/lÌ¡g|·u�s �Us�¯ ��|¢u�y_{g��q� tiHx���iA~NsviHs´1e�i6{ ©�~U{g{g|�y_{ ��~U�wuw|}x�|���~U{@u � sXi6q_i��¢iH~L­_iHs+uwe�i� tiA��~U�wuwzg��i�x6i6���*®Ë´1egi6��i�³E|��_|¢u�~U�mª¨|} tiAyÉh�y4­r|¢i�|�s g|�sw�g�}~Lq_iA P¯�~4uZÊH����ÊAÈÌ~_{� (ÊH���ë�U²g»&d e�i$��~_�vu�|�x6|¢�P~U{@u�xA~U{(� u�´�~Uu�x�e�u�egi£h*y4­r|�i/~_{rq@h�yN�wi±|¢¿E|¢u+{gyUu��ytx6~UuwiA �|�{�sv|} ti+|¢u�s�ºPi6�} �y_¿�­r|�i6´�»±d eg|}s�¿Ë~Nx!u�~U�}svy£i6¶r����~_|¢{�s�´1erq�uwegiA�wi+~U��i+svyNh�i� gi6�}~LqrsA°Á��~Nx�Ä_i6u��yNs�swiAs ~U{� ���|¢uvuwiA�E~Uu�u�egi�s�~Uh�imuw|�h*iN»

�-|¢�Nzg��i�È �ųE~Uu�~��N~UuwegiA�wiH X tz��w|�{g�+³1ªµswiAs�sv|�y_{

����� � ! �8� � � � � . #+!%*"(����:m��y_¡P~U���¢qN°tuwegi�uw��~4Ô±x���i6�}~4uwiH $uwy± tzgh�h2q/x6�¢|�i6{@u�sE tyriAs1{�yUuE t|}svuwzg��¡£yUuwe�i6�ch2zg�·u�|�xA~_svucÜ�y4´cs1��iAx6i6�t¸u�|¢yN{Á»�1i6¿Ài6���w|�{g�*uwy�yNzg� uwiHs�u¨s�x�iA{�~U��|¢yP°t tzgh�h�q$��~U�wuw|}x�|���~U{@u�s�s�x�iA{�~U��|�yNs�|¢{r­Ny_��­_i �

ÝÀÞ-ßÁÝáà

Page 22: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� ÊH�

��U�N�� tzgh�h2q&~L­L~Uu�~_��s��Ni6{giA��~UuwiH �¿À�wyNh5©¬~U{�{g|¢yN{�uwiA�wh�|�{�~U�1~_{� ���yrxA~4u�iA &|�{&u�egi£ ti6��~_�vu�zg��ix�iA�¢�S°g´1eg|}x�e/sw|�h�zg�¢u�~_{gi6yNz�sv��q���yN|¢{Z~_x�uw|�­_imh�zg�¢uw|}x6~Ns�uc�N�wyNzg��®S�_��Bt»�Ê_» Bt»�ÊH�_¯

��U�N�Xy_uwegiA�� gzgh�h�q�~L­4~4u�~U��s¨�Ni6{giA��~UuwiH Z¿À��y_h pryN�geg|}~±u�i6��h�|¢{�~_�a~U{� ¾s�x6~4uwuwiA�wiH Ìi6­Ni6��qr´1egi6��i|¢{Psv|} ti��_��~U��eg|�xEi6{r­r|��wyN{gh�i6{@uA°t´1eg|}x�e2��y_|�{/��~U{P ty_h h2zg�¢uw|}x6~_svu1�_��y_zg�Ps6»kE{Iuwegi£y_{�iXe�~_{� �°�©�~U{g{g|�y_{  tzgh�h�|¢iHs� ty_{(� u��_i6{�i6��~4uwi/~_ g g|·u�|¢yN{�~U��uw��~4Ô±x�®Ësw|¢{�x6iXu�egi6q£��zPs�u

��yN|¢{±uwegi�sw~_h�i¨i�¶t|}s�u�|¢{���h�z��·u�|�xA~_svu��N�wyNzg�P¯!»akE{+u�egiEy_uwegiA�9eP~U{� �°gpryN�geg|}~� tz�h*h�|�iAs ~U��ic�gerqtsw|�xA~U���¢qs�x6~Uuvu�i6��iA �|�{�sv|} tim­r|¢�wuwz�~_�P´�y_���} �°N´1e�|�x�e±|�h��g��|¢iHs�~��_��iA~Uu�{rzgh�¡Fi6� yU¿Á{�i6´(��iAx6i6|�­_i6��s�¿ÀyN�9{giA´(h�z��·u�|·¸xA~_svu¨�_��y_z���s6»1Ǩi�u�´�y_��ÄXiA�@zg|��gh�i6{@u�sc|�{�sv|} ti2ªEd1¹¨³ h�zPs�u¨h+~_|¢{@u�~_|¢{£u�egi�h2zg�¢uw|}x6~_svu¨��y_ztu�|¢{��+u�~_¡g�¢i®w®>p\° :�¯1svu�~UuwiAs�¯!»Åd erz�sA°gh�z��·u�|�xA~_svu�u���~UÔ±xE|�{�sw|� gi�ªEd1¹¨³µ{gi�u�´�y_��Ä+|�sc{gyUuc t|��wiHx!u��¢q±���wyN�PyN�vu�|¢yN{�~U�Fuwyu�egi�{rzgh�¡Fi6�1y_¿-��iAx6i6|�­_iA��sA»d egy@svi �Eyrp�h�iH~_swzg�wiAh�i6{@u�sÅswegy4´csÅ~�swz�x6x6iAs�s�¿Àzg��{gi�u�´�y_��Ä� ti6��|�­_i6��q�y_¿Fh2zg�¢uw|}x6~_svu Y¨³E����~Nx�Ä_i�u�s6»

��zg�wuwegiA�wh�y_��i_°P{gyX�P~_x�Ä_i6u¨��yNs�s¨x�yNzg�} Z¡Pi* ti�u�iAx�uwiA Z¿Ày_�m{gy_{t¸O��iA~U�Áuw��~4Ô±xU°\svzPx�e�~_scuwi�¶rumh*iHsws�~U�Ni�y_��Ni6yN�_��~U�geg|}x6~_��ÜPy4´cs6»d eg|}sEº���s�umh�zg�¢uw|}x6~Ns�umuwiHs�u�x6~Uh���~_|¢�N{Ì|}s¨�N�¢yN¡�~U���¢qZswz�x6x6iAs�s�¿Àz��-sw|¢{Px�i�iH~_x�e�sw|¢uwi2xA~U{�{gy4´ z�swi2¤2¥

¦t§�¦&~_{� &x�yNh�h�zg{g|}x6~Uuwi$´1|·u�eIyUu�egi6�*��~_�vu�|�x6|¢��~_{@u�s�u�eg��y_zg�Ne&ªEd1¹E³ ÂÃ� {gi�u�´�y_��Ä\»¢»�ƨs*~Ì��iAswzg�¢uA°y_uwegiA�Eªmd1¹¨³¨¸Ox6y_{g{�iAx!u�iA �i6{@uw|¢uw|�iAsE|¢{@u�i6��iAsvuwiA Ì|¢{�uweg|}s�~4uvu���~Nx!u�|¢­Ni�i�¶t�Fi6��|¢h�iA{Nu�~4u�|¢yN{Ze�~L­_i2�wiHx�i6{@u��¢q��yN|¢{/z�sA»

� + ,�. ���-� �¬,�' � �!" ,�" $ � �!�¬"-#$���I%('*)����-,�'£.01'2" �Æ ��~_�w�Nic{rzgh�¡Fi6��yU¿�ª¨|��vu�z�~U�F«a{r­r|¢��y_{gh�iA{Nu�s¨®Ëª¨«9¯�~U���g�¢|}x6~Uuw|�y_{�s�e�~L­_iE¡PiAi6{X giAsw|¢�N{giA ±swy�¿Ë~_�A»�¹ciA�wi´�i*h�~_|¢{��¢q£¿Àytx�zPsEyN{�ªE« ~_�g�g��|�xA~4uw|�y_{Pscu�e�~4u�z�swiAsEh�zg�¢uw|}x6~Ns�u�x6y_h�h�zg{�|�xA~4uw|�y_{¬»�pri6­Ni6��~U��~_��x�e�|·u�iAx!¸u�zg��iAs�svzPx�e*~Ns-Ǩ�9ptǨ«�d �ÊA��S°_³EÂꨫ ²�O°_lÌÆmpgprÂꨫa¸Ã�$ ��O° :��1«a«�Çmpr��ƨj9« ë�_����~_{� 2pr�9©ÁÂ�Çc« ë�2�eP~L­_i�~_�¢��iA~N tq^¡PiAi6{  giAsw|¢�N{giA  z�sv|�{g�Éh�zg�¢uw|��g��i�h2zg�·u�|�xA~_svu/�N�wyNzg��sA» Çc�9ptǨ«�d �ÊA���|}s$uwegi�º���s�u³E|}s�u��w|�¡gztu�iA ½ÂÃ{@uwiA��~Nx!u�|¢­Ni�pr|�h�zg�}~4u�|¢yN{ ®Ë³EÂvpg¯$~U�g�g��|}x6~4u�|¢yN{½uwyIz�svi�ÂÃ� h2zg�·u�|�xA~_svu$�g��yUu�ytx�y_�S» d egiǨ�9ptǨ«�d^ª¨«�|}sa��~_�vu�|·u�|¢yN{giA *|�{@uwy�egi6¶t~_�_yN{�~U�gx6i6����sÅ´1e�|�x�e±~_�wic~Nswswytx�|}~4uwiH �´1|¢uwe+h2zg�¢uw|}x6~_svua�_��y_z���s6»³EÂꨫ ² ��z�swiAsE~��wiA�g�¢|}x6~UuwiH £´9yN�w�} £ g~4u�~U¡�~Nsvi�~_{� £�PiAi6�w¸>u�yU¸O�PiAi6�cx6y_h�h�zg{�|�xA~4uw|�y_{¬» d�y±zg�\ g~Uuwi�~_{yN¡t��iAx�uA°U~mh�iAs�sw~_�_i9|�s�swi6{@u�u�y�~U���@�Fi6iA��s�u�ymz��F g~Uuwi�uwe�i6|��-y4´1{2�wiA�g��|�xA~_s�~_xAx�y_�� t|�{g�_��q_»�d¬ym�wiH tz�x6i9{gi6uv¸´�y_��Ä�uw��~4Ô±x_°tuwegi�yN¡t��iAx�u�s1|�{/uwegi�³EÂꨫ½­r|��vu�z�~U�¬´9yN�w�} X~_�wi�eg|�i6��~U��x�eg|}x6~U����q±x�y_h��FyNswiA /~U{� £xA~U{£¡Pi~Nswswytx�|}~4u�iA 2´1|·u�eX~�svi6u�yU¿�eg|�i6��~U��x�eg|}x6~_�th�zg�¢uw|}x6~Ns�u��N�wyNzg��sA»�lÌÆmpgprÂêE«Å¸Ã��|�s9~�x�yN�¢�}~U¡Fy_��~4u�|¢­Ni�­r|��vu�z�~U�iA{r­@|���y_{gh�i6{@umuwe�~Uu�~U���¢y4´csEz�swi6��s¨u�y£|¢{@uwiA��~Nx!u�´1|·u�e�iH~_x�e�yUuwe�i6��y4­_iA�m~£x�yNh�¡g|�{�~Uuw|�y_{�y_¿��_��~U��eg|�xAs6°~_z� t|�y$~_{� Zu�i�¶ru�h*iH t|}~g»�ÂOu�z�swiAsm¡Py_uwe¾~$x6�¢|�i6{@u �UsviA�w­Ni6�m~U��x�eg|·u�iAx�uwzg��i2~_{� Ìh2zg�·u�|�xA~_svuA»�d e�i*swi6��­_iA����wy4­r|} tiAs-u�egic��~_�vu�|�x6|¢��~_{@u�sÅ´1|¢uwe±~_{*|�{g|¢uw|}~U�P�PyN|¢{@u�y_¿\~Nx6x�iHswsÅuwy�uwe�icª¨«I~_{� *i6{@uw|¢uw|�iAs9~U��i1�wiA�g��|�xA~4uwiH yN{/ gi6h+~U{� /~U{P $~_�wi�~_s�svytx6|�~UuwiA X´1|·u�e£h�zg�¢uw|}x6~Ns�u1�_��y_z���s6»-ÂÃ{ :��1«a«�Çmpr��ƨj9« ë�_���O°tiA~Nx�e$��~_�vu�|�x6|·¸�P~U{@u�u���~_{�svh�|¢u�s9|·u�s9svu�~UuwiEz�sv|�{g�2h�zg�¢uw|}x6~Ns�u ~U{� ±~��¢|��_e@u�´�i6|��_e@u9swi6��­_iA�9~_s�sw|¢�N{�sÅh�z��·u�|�xA~_svu ~N g t��iAs�sviHs~_{� 2|¢{t¿ÀyN�wh+sÅ�P~U�wuw|}x�|���~U{@u�s�y_¿Fx�e�~_{g�_iHs�|¢{*u�egi1ª¨«c»NÂÃ{±pr��©ÁÂ�Ǩ« ��S°_uwegi1ªE«�|�sa g|¢­r|} tiA *|�{Nu�y�sviA­_iA��~_�ÒAy_{giHs±®ÀyN�I��&1���^��� �v¯!°Å´1eg|}x�e�e�~L­Ni±~U��¡g|·u���~_�wqÌsw|�Ò6iX~_{� �sveP~U�FiX~U{� �~_�wi±~Nswswytx�|}~4u�iA ¾´1|·u�e�h�zg�¢uw|}x6~Ns�u�N�wyNzg��sA»+ÂOu�z�swiAs�~£ t|}s�u��w|�¡gztu�iA �~_��x�eg|¢uwiHx!u�zg�wi*|�{�´1eg|�x�e�iH~_x�e¾{gyt ti+h+~U|�{Nu�~U|�{�s�~£��~_�vu�|�~_�ax�y_�rqÌy_¿u�egi�ª¨«½x6y_���wiHsv�Fy_{� g|¢{g�2uwy*u�egi�~U��iA~2yU¿�|¢{@u�i6��iAsvuA»d egi* ti6�P~U�wuwh�i6{@uEy_¿�³¨i6¿Ài6{�swi�eP~_sE¡PiAi6{Ì�gz���swzg|�{g�±|¢u�sEy4´1{�~U��x�eg|¢uwiAx�uwzg��i_°Fx6~_�¢��iA Ì¹E©¬Æ � �S°P¿Ày_�

­r|��vu�z�~U�9i6{r­r|¢��y_{�h*iA{@u�|¢{@uwiA�wyN�PiA��~_¡g|��¢|¢u�q�´1eg|}x�e�e�~Ns�¡Fi6i6{I�wiHx�i6{@u��¢q�~_ tyN�tuwiH �¡rq�u�egi±Âëa«a«¨»�¹E©¬ÆºP�·u�i6��|¢{g��h�iAx�e�~_{g|�swh+s�~U��iX¡�~NsviH �y_{ ³¨Âvp&i�¶t�PiA�w|�i6{Px�i/´1|·u�eIh�z��·u�|�xA~_svu�~_{� &z�swi$uwegi£x�yN{�x�iA�tu*y_¿

ß � é�n�o�p�q�r

Page 23: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

�_� � ����( �"�� ����^� �*� �^���

� &^� � ��"G� �;��� ��� �!»9Æ���y_ztu�|¢{g�±sw��~Nx�i�|�sch�~N ti�yU¿ ����������� �!� � &^"¾�wiA�_|�y_{�s x6y_���wiHsv�Fy_{� g|¢{g�2uwy+h�iAh�¡Fi6� � si6¶t�g�wiHswsw|�y_{�y_¿9|�{@uwi6��iAsvu�~U{�  ����� �^� �+��i6�N|¢yN{�sEuwe�~Uu�i�¶t�g��iAs�sm´1e�~4u�~/h�i6h�¡Fi6��|�s�~_¡g�¢i*u�y/���wyt tz�x6i_Ó��i6�N|¢yN{�s�~U��i+�wiHx!u�~U{g�N�¢i+~U��iA~Nsm|¢{�u�egi+�wyNztuw|�{g�Ìsw��~_x6i_»±¼½e�|¢��i�uwegi$³¨Âvp¾�g��yUu�ytx�y_�Å|}s�x6�¢y@sviA�¢qÌ��|�{gÄ_iH ´1|¢uweXuwegim�g��y_�Fi6�wuw|�iAs�yU¿¬h�|��¢|¢u�~_�wq�zg{g|¢u�s�~U{P ±­_iAeg|}x���iAsA°_u�egiE��~4u�|¢yN{�~U��ic¡Fi6eg|�{� $¹¨©¬Æ |}s�u�e�~4u�|·u1x�yNzg�} ¡Fi1z�swiA *´1|¢uwe± t|¢ÍFiA�wiA{@uÅu�q@�FiAsayU¿�sv|�h�zg�}~4u�|¢yN{�s1®À{�yUu�yN{g�¢q�h*|���|·u�~U��q2~U���g�¢|}x6~Uuw|�y_{�s�¯-~U{� *|¢u�|}s�u�~_�w�Ni�uwiH u�y4´�~_�� �s�{giA´ sw|�h�zg�}~4u�|¢yN{/ tiA­_iA�¢yN�gh�i6{@u�sA»Ç¨y_{gi yU¿PuwegiHsvi1 t|¢Í\i6��i6{@uÅ´9yN�wÄts�e�~L­_i9�g�wiHsviA{@uwiA 2~U{�~U��x�eg|¢uwiAx�uwzg��i9uwy� tqr{�~Uh�|}x6~U����q���~U�wuw|¢uw|�y_{2uwegi

ªE« |�{@uwy/h�zg�¢uw|}x6~Ns�u��_��y_z���s6°Fu�~UÄr|¢{��$|�{@uwy£~_x6x6y_zg{@umuwegi+ tiA{�sw|·u�qZy_¿���~U�wuw|}x�|���~_{Nu�sm�PiA��x6i6���Å~U{� �uwegi�P~U�wuw|}x�|���~U{@u�s��tx6~_��~_x6|·u�|¢iHs6»�ªc¸O« m«½|�s yN{gi�yU¿�uwegi�º���svu1~_�g�g��|�xA~4u�|¢yN{Xu�y+|¢h��g��i6h�i6{@u¨swz�x�e£~*s�x6~_��~_¡g��i~_��x�e�|·u�iAx!u�zg��i¨¿ÀyN�c~2�}~U���_i�s�x6~U��i�­r|¢�wuwz�~_��i6{r­r|¢��y_{�h*iA{@uA»

� + ,�'/�9��# �¬�6,�' ��'$7��$#±"-#X���� ,����¼¾i� tiAs�x���|¢¡FiA (egy4´ uwegiÉÎ\Ï\Ð�Ñ�¦^�_iA{gi6��~U�mx�y_h�h2zg{g|}x6~4u�|¢yN{½¿À��~Uh�i6´�y_��ÄÉxA~U{ i6ÍFiHx!u�|¢­Ni6��q e�i6��� |�{|�h��g��i6h�i6{@uw|�{g�/uw��~4Ô±x�swi6�_h�iA{Nu�~4u�|¢yN{Á°Á~U{� �uwerz�s�~Nx�eg|�i6­r|¢{��/~/­_iA�wqZe�|¢�Ne���i6­Ni6�ÅyU¿ swxA~U�}~U¡g|���|·u�qZ|�{¾~ªm©�pr«¨»t¼�i�~U�}svy2y_ztu��¢|�{giH ±egy4´ swz�x�e/~���~4uwe�i6��­_y_�}~4u�|¢��i_°@��yrxA~4u�|¢yN{t¸O gi6�Fi6{� g~_{@uA°t~_ g g�wiHswsw|¢{���swx�e�i6h�i_°xA~U{+¡Fi¨i6ÍFiHx!uw|�­_iA�¢q+x6y_zg�g��iA �´1|¢uweÌÎ\Ï\ЬÑ�¦@¸Ozg{�~L´ ~U��ic~U���g�¢|}x6~Uuw|�y_{�sA°Nswz�x�e±~NsÅuwe�iE³1ª svzg¡Psvqtsvuwi6h£°N¿Ày_�~�swh�y@y_uwe/|¢{@u�i6�_��~4u�|¢yN{Xy_¿-¡FyUu�e£~_�g�g��yN~Nx�egiAsA»d egi�|�h��g��i6h�i6{@u�~Uuw|�y_{�s¨~U{� $i�¶t�Fi6��|¢h�i6{@u�~4uw|�y_{Ps1 tiAs�x���|¢¡FiA $|�{$u�eg|}s1��~U�Fi6�E~U��im~_�¢�Á¡P~_swiA $y_{/uwegi

Æmptl ÜP~L­_yN��yU¿�ÂÃ�Éh2zg�·u�|�xA~_svuA»�¼¾i�~_�wimx�zg����i6{@uw��q�´9yN�wÄr|�{g��y_{/~*p�ptl£¸O¡�~_swiA $~U�g�g��yN~Nx�eÁ»-p�ptl ´ ~_s|�{g|¢uw|}~U���¢q�|�{@uw��yr gz�x�iH &svy�~_s�u�y�iH~_swiXh�z��·u�|�xA~_svu* tiA�g�¢y4qrh�i6{@u2~Uu�u�egiX{gi6u�´9yN�wľ�}~Lq_i6�H°�sveg|¢¿áuw|�{g��uwegi¡�zg�� gi6{�y_{@uwy/u�egi±~U�g���¢|}x6~Uuw|�y_{Á°�{gyUu�~U¡g��qÌ¿ÀyN��sviA{� ti6��swy_z���x6iAs�h+~U{�~_�_iAh*iA{@uA»±Æc�¢uwe�y_zg�Ne�u�egi$pgpglh�yt tiA�1h�~Lq&~Uu+º���s�u��_�}~U{�x6i£�¢yry_Ä�­Ni6��q�h�y_��i/~_�g�g��y_�g��|�~Uuwi$¿Ày_�+svuw��iA~Uh�|�{g��uwe�~_{É¿ÀyN��|¢{@uwiA��~Nx!u�|¢­Nix6y_h�h�z�{g|�xA~4u�|¢yN{�s6°N´9iE¡PiA�¢|�i6­Ni¨|¢u�|}s9�Py@swsw|¢¡��¢i1u�y�u�~UÄ_im~_ t­4~_{Nu�~U�Ni1yU¿Áu�egiEx6i6{@uw��~U�P�wyN�¢icy_¿Áuwe�i�Î\Ï\Ð�Ñ�¦x6y_h�h�z�{g|�xA~4u�|¢yN{�~U��x�eg|·u�iAx�uwzg��ia~U{� �uwy¨¡�zg|¢�} �~_{2pgptl£¸O¡�~NsviH �ªE©�pt«�´1|¢uwe�~1­Ni6��qm~UÍFyN�� �~U¡g��ia~Uh�y_z�{Nuy_¿-x�e�~_{g�_iHs ~4u1uwe�i�~U�g�g��|}x6~4u�|¢yN{$�}~Lq_iA�A»pryc¿Ë~U�H°A´�i�x�yNzg�} �{gyUuÁºP{� �~1svu�~U¡��¢ia­Ni6��sv|�y_{�y_¿@u�egi�©¬|¢{rzt¶�Ä_iA�w{giA�4uweP~4u¬|}s¬x6y_h��g��|�~_{Nu�´1|·u�e�Â�:�lZ�Ÿ

­t²+~_{� /�aÂ�l£¸O­t�g°g´1eg|��¢i�¼½|¢{� gy4´cs ¶t�Ìx��}~U|�h�s1uwy+e�~L­NiEu�eg|}s¨x6~_��~U¡�|¢��|·u�q${�~4u�|¢­Ni6��q_»�d eg|�sc|�s1´1erq$uwegi¤2¥w¦r§-¦$~_�g�g��|�xA~4u�|¢yN{$|}s1x�zg����i6{@uw��q±¡Fi6|�{g����~U�wuw|}~U���¢qX�PyN�vu�iA $y_{/uweg|}scptlÌlZ¸OxA~U��~_¡g�¢i��g�}~4uw¿Ày_��h£»Æ1 g g|·u�|¢yN{�~U���¢qN°LuwegiA�wi9¡PiA|¢{��¨{gyEi6­r|� gi6{�x6i�yU¿gÂÃ��h�zg�¢uw|}x6~Ns�u-¡PiA|¢{g�my_{�i� g~Lq�~L­4~U|���~_¡g�¢iÅyN{�uwe�i9ÂÃ{@uwiA�v¸

{�i�u�|�{+uwe�ic��~_�w�Ni ¸¬i6­Ni6{+zg{P ti6�9|·u�sa�g��iAswzgh+~U¡g��q�h�yN�wi1h+~U{P~U�_iH~U¡g��i¨pgptl ¿ÀyN�wh ¸�h+~_{@q*~U�g���wy@~_x�egiHseP~L­_i*¡PiAi6{��g��y_�FyNswiA ��wiHx�i6{@u��¢qZ|�{¾uwegi±swyU¸Ãx6~_�¢��iA �~U�g�g��|}x6~4u�|¢yN{t¸O��~LqNi6�mh�zg�¢uw|}x6~Ns�u�~U��i6{P~g»+d egyNswi+~U�t¸���wy@~_x�egiHs��Ni6{giA��~_�¢��q��wiA�¢q�yN{É~U{ zg{� gi6���¢qr|�{g��y4­Ni6����~Lq¾{gi6u�´9yN�wÄ�swz�x�eÉ~Ns�u�egiZy_{�iAs*|¢{@u��wyt tz�x6iAs*|�{�Fi6iA�v¸Suwy_¸S�Fi6iA��uwiHx�eg{gyN�¢yN�_|�iAsA°�~U{P �´9iX~_�wi$x�y_{Psv|} ti6��|�{g�£uwy�svuwzP tq¾uwegi+¿ÀiH~_sw|¢¡�|¢��|·u�q�y_¿1~�Î\Ï\ЬÑ�¦@¸O��|¢ÄNih�yt tiA��|¢{Zswz�x�eZ~2�PsviAz� tyU¸Oh�z��·u�|�xA~_svu�iA{@­r|��wyN{gh�i6{@uA»

ÝÀÞ-ßÁÝáà

Page 24: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

������¤�¥w¦t§�¦������ ���������������������������������! #"�$%���'&�"�()�*"�� �gÊ

� 134 ��1'$���� ¢Ê � � �^$^�^"������ � ��"���� � &^� "-� �]�'���_��� � �� � �'��»�e@uvu�� � � �L´1´1´�» ~U�}s�~4¸O�g�wy_��iAx�uA» y_��� �r» ��=/P»t¼ »39 ~U����z�s6°t��»PjE»t¼�~4u�i6��s6°g~_{� /³�»39m»gƨ{� ti6��swy_{Á»�©Áytx6~_�¢iHs �aprz��g�PyN�vu�|¢{��*�}~U���_iEh�zg�¢uw|�z�swi6�­r|��vu�z�~U�-i6{r­r|��wyN{gh�i6{@u�sA»�� T T ��T&^()�!� � �*� � �'�����_� � �I�^"-� � � ��� � ���^� � &^""�!°Á�P~U�_iHs�ÊH��®Ë�@¯ � BU��� B�Mt°Ç¨y4­_iAh�¡Fi6��ÊA�N�_��»

² ��jE»�j�~_�w�}swswy_{±~_{� /k2»t¹E~U�Ns�~U{P �»¬³E|¢­Nic¸a~�h2zg�¢uw|\z�swi6��­@|��wuwz�~_�F��iA~_�¢|¢u�q�svqtsvuwi6h£»�ÂÃ{ �#�'&1����������"G� �� T T �� ����P°gpriH~4uwuw��i_°g¼�~_sweg|�{g�Uu�y_{Á°�priA�tuwiAh�¡Fi6��ÊH�_�N²g»

� �=/P»N³m~Ue�h�~_{Á° /�»@��»_¼¾iA~UuwegiA�w��q_°@~U{�  ��»���z�eg�>» � �'���^� ��"G���T&�(��� � �� �!��( � ������� &�"I�!2��� �( ��� �]"�*"�� �'&��^������ &�"7� &7���K��� � �@�I���*$^�� �]�'���_��� ���*� � �'�6»-���wiA{�x!u�|�x6i�¹E~U���>°¬ÊA�_�N�g»

B� �i� � ��� � � ����� �^�]��� ��� & � � �^""� ��&^��� ��2��� �*(*»�eNuwuw� � � �4´1´1´�» sv¿ËxU» ´1|} ti_» ~_ �» ��� �U³1ªEdcp\» � ��jE» :m��i6iA{ge�~U���_e¬»�³Eqr{�~Uh�|}xU°�iAh�¡Fyr g|¢iH Ìh�z��·u�|�xA~_svum�N�wyNzg��sc|�{�h+~Nswsw|¢­Ni�¸��t»�d¬iHx�eg{g|}x6~_�-�1iA�PyN�vuÇ�kmd1d¨j p@¸Ãd1� ¸O�N�4¸ÃȱÊN°�Yc{g|�­_iA��sw|¢u�q+yU¿ÅÇcyUuwuw|�{g�_eP~Uh£°�ÊA�N�_�g»

M2��ª2»-¹E~U�� th+~U{&~_{� �l�»-ÂÃÄ_i6{¬»/«�{ge�~U{Px�iA &�wiH~U��|·u�q¾~Uz� t|�yÌ|�{&|�{Nu�i6��~_x�uw|�­_i+{gi6u�´9yN�wÄNiA ¾i6{r­r|¢��y_{g¸h�iA{Nu�s6»ÅÂÃ{�� �'�^()��� &^���)�*&^���*"�� �*�'���*� ��$^���������������� #"�$1���'&^"�( �"��;�������K�� ��4°ÁÊH�_�N�g»

È ��³2»���zgu�swegi6� /P»�k¨uvu±~U{P ½jE»Å��iA�wÄr|�{�s6»½d egiZh�iHsws�~U�Ni$¡gzPs �ÌÆ �g��~Uuv¿ÀyN�wh ¿Ày_�±x�yNh��PyN{gi6{@uv¸¡P~_swiA ^x�yN{t¿Ài6��i6{�x6|¢{��&~U�g�g��|}x6~4u�|¢yN{�sA» ÂÃ{ ���K� � ����!#"%$�$�$ � &����2�'��&�� &^"&�R&�(��&^"��*"�� ������*� �� �'&����� ���'��°\�U�N�_�g»

� �'��»(�Ey_¡�~Lq@~_sweg|>°PÆ�»¬kE�N~L´ ~g°Pp�»�j�~Nsv{giA�A°\~U{P �jE»�9�yN�wh+~U{�{Á»E�9uw����~Lqr�¢y@~_ /¿Ày_��h+~4uc¿ÀyN�2ÊL�L¸O¡g|¢u �~4u¨~UzP t|¢y+~_{� /�_�4¸�~_{� /�U�U¸O¡g|¢u ��|�{giA~_�csw~_h*���¢iH $~_z� t|�y�»)�� � �+*-,/.�$U°F�_�_�N�g»

�ÊA� ����»0�¨yN¡�~LqN~Nsveg|S°rÆ�»\kE�@~L´�~�°rp�»Fj�~_sw{gi6�H°g~U{P ZjE»799yN�wh+~_{g{Á»a�9uw�£��~Lqr��yN~_ ±¿Ày_��h+~4u ¿Ày_�¨ g­�®À|�iAx��ÊAÈN²U�@¯�­r|� gi6y�»)��1� �+*�,/2�.U°\�U�_�@�t»

�Ê_Ê �$9m»LÇ�»H©Ái6­r|�{gi_°/P»Lj9��y4´�x6�wy_¿áuA°4jE»H³E|¢y_uA°/P»�/P»�:�~U��x�|}~4¸Ã©Áz�{�~4¸ÃÆ1x�iA­_iAsA°6~_{� =/�» ��»3��zg��yNswi_»Nj9yN{�sw|� r¸iA��~Uuw|�y_{/yU¿-�wiHx�i6|�­_iA� |¢{@uwiA�wiHs�u |�{£x6y_{@uwiA{@u�¿ÀyN�1|¢�£ tiA�¢|�­_iA�wqN»-ÂÃ{ �#�'&1����������"G� ���' T 4�657� 8�� 8 �Z°�_�_�N�g»

�ÊH���9 ����*��� � �:�T&�� ���;� � � ����$A»�eNuwuw� � � �4�¢|�¡\ t­\» swy_zg��x�i6¿Ày_���_iN» {gi6u �t» �ÊA² �m«¨»F© ��u�q_°P©a»-:�~_ztuw|�i6�H°�~_{� �jE»P³E|¢y_uA» lZ|�h�~_Ò6iN°�~±²_ /h2zg�·u�|·¸O�g�}~Lq_iA�1�N~Uh�i�yN{$u�egi�|�{@uwi6��{gi6uA»�ÂÃ{

� �'&%����� �^��"_��=<K� �'��"�� ���"!����� &�"!���>�R&�"��*��'�"!��� &�"P� � � �?�1�������������_��2��� �*($�#�^" � �i� � � � ��� ��� �@�4°:m|¢¿ÀzÁ°-/N~_��~U{Á°tǨy4­_i6h2¡PiA��ÊA�N�_Èg»

�Ê6� �m«¨»U©(��u�q�~_{� �d�»4d�zg���¢i6uvuw|S»tÂ�s�svzgiHs¬|�{� tiAsw|¢�N{g|�{g�E~mx�yNh*h2zg{g|}x6~Uuw|�y_{�~_��x�eg|¢uwiHx!u�zg�wi�¿Ày_���}~U���_i�¸Ãs�x6~U��i­r|��vu�z�~U��iA{r­@|���y_{gh�i6{@u�s6»-ÂÃ{ �#�'&1� �R&�� �����A,���B��"�� ���"!����� &�"!���C! &����2�'�K& �W&�"#5 ��D� &^������� � �'&^����T&�( ( � "�� ���^� � &^"P°��a|}s�~g°tÂOu�~_�¢qN°ÁÊ@ML¸�ÊH��Ǩy4­_i6h2¡PiA��ÊA�_�N�g»

ß � é�n�o�p�q�r

Page 25: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

�N� � ����( �"�� ����^� �*� �^���

�Ê1B�m«�h*h+~_{@z�i6�Å©(�6u�q_°\d eg|¢iA�w��q£d¬zg����i�uvu�|>°�~_{�  �g��~U{���y_|}s�9 ~Nx6x�iA�¢��|S»Eptx�yN�wi �c~Xs�x6~U�}~U¡��¢i�x6y_h�h�zg{�|·¸xA~4u�|¢yN{±�g��yUuwytx6y_�t¿ÀyN�9�}~U���_i6¸Os�x6~_�¢i ­r|¢�wuwzP~U��iA{r­@|���y_{gh�i6{@u�s6» � & � � �����^� ��" �' T T �� �A��� �K�'��""�� ���� � &^"�� &^"�5 �*�D� &^������"G� &^� ��"��^�è°-/_z�{gi��U�_�_��»

�ÊA� ��lÌ|�x�e�~_i6�Å��»ÁlÌ~Nx�iH ty_{g|}~g°Á³Ey_{P~U�} Ì��»�9��wzguwÒ6h+~_{Á°ÁlZ|}x�e�~UiA���\qr �~g°Á³m~L­@|} ���»��a��~UuvuH°Á�Å~Uzg�ad�»9 ~_�we�~_h£° /_yNeg{ ��~_�¢¡rqN°_~U{� $/_yNeg{2©¬ytx�Ä_i_»rÇc��ptÇc«�d �NÆÉh2zg�¢uw|¢¸S�g�}~Lq_iA��²N �­r|¢�wuwzP~U�ri6{r­r|¢��y_{�h*iA{@uy4­Ni6��uwe�i�|¢{@uwiA�w{�i�uA»ÅÂÃ{ �!^(��&2����� ( &�"��*"�� �*�'���*� ��$^� * � � �'� �K�_� � �!°���~_�_iHs1�_² �t�U�P°r�gÊA�g°\ÊH�_��Bg»

�Ê@M2��pruwi6­Ni6{�lÌxLj�~U{g{gi+~_{� �ªa~_{�/N~Nx�y_¡PsvyN{Á»�­r|}x ��Æ ÜPi�¶t|¢¡��¢i�¿À��~Uh�i6´�y_��Ä/¿Ày_����~Nx�Ä_i6u�­r|} ti6yP»�ÂÃ{�A��� �i� � � ��( � �^� �U°P�P~U�_iHs BtÊ_Ê � BN�_�t°PÊA�N��Bt»

�ÊAÈ � �i� � � � ���2����� �'���;� �7&^"���� &�����"G�P��&1&^�·»ae@uvuw� � � �L´1´1´�» h*iA��x6|>» x���xU» x6~ �Lh2¡PyN{gi �UlZzg�¢uw|}l�kmÇ �t» �ÊA� ��ƨÄr|¢h�|}x�eg|�kE�N~L´ ~g°0��~Uu�swz�sweg|B�Ey_¡P~LqN~_sweg|S°0��~_Ò6zg{gyN�w|�przg�N|¢zg��~g°¬kms�~Uh2zÌǨ~UÄ4~_h�zg��~g°\~U{�  /_z�{lÌzg��~_|>»�³EiAsw|¢�N{/~_{� X|�h��g��i6h�i6{@u�~Uuw|�y_{$yU¿- g­±¡�~_swiA X­r|� tiAy�y4­_i6���wuw�Á»-ÂÃ{ � � �@� �� ��� � ��& ! &^��� ��'��&��F°\�U�N�_�g»

ë�U� ���R��"���� ����� ��&^��� �*&^� �T� ��� � ������� � �������^($�!»Åe@uvuw� � � �L´1´1´�» svh+x6x_»  gi6h�y_{Á» {g� �L´�i6¡\x6~_h �t» ë�tÊ ��¹¨i6{g{�|¢{g�Xpgx�e@z��¢ÒA�w|�{g{giN»=��� � � &1&^� �!»Åe@uvu�� � � �L´1´1´�» x6sA» x6y_��zgh�¡�|�~�» iH tz �LÂ���d �Usvy_¿áu�´�~_�wi �L�wuw�tu�y@yN��sA» ë�_��m��»gptx�er´ ~U�wuwÒ_°@9m»tj�~_h*��¡PiA�¢�S°gp\»td�~_{g{gi6qN°rp�»� aiA{Á°g~U{� Xd�»rpre�i6{Á»ÁªE|¢�wuwzP~U�F�g��~Lqr�N�wyNzg{�  �-Æc��x�eg|·¸u�iAx�uwzg��iAsc¿Ày_�¨~±swe�~_�wiH $­r|��vu�z�~U�¬´9yN�w�} �» �A� � �!^(��&2����� ( &�" �������������� ����� ���� ��&+���D� �^� � ��"-������ � "!&���&'� 4°\Çcy4­_iAh�¡Fi6��ÊA�N�_È�»

ë�U² �������!�'& �*� � �� � ���1»�e@uwuw� � � �4´1´1´�» ­@uweP �» yN�w�P»

ÝÀÞ-ßÁÝáà

Page 26: A Very Large Scale Virtual Environment for multimedia … · Unité de recherche INRIA Sophia Antipolis 2004, route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex (France) Téléphone

Unité de recherche INRIA Sophia Antipolis2004, route des Lucioles - BP 93 - 06902 Sophia Antipolis Cedex (France)

Unité de recherche INRIA Futurs : Parc Club Orsay Université - ZAC des Vignes4, rue Jacques Monod - 91893 ORSAY Cedex (France)

Unité de recherche INRIA Lorraine : LORIA, Technopôle de Nancy-Brabois - Campus scientifique615, rue du Jardin Botanique - BP 101 - 54602 Villers-lès-Nancy Cedex (France)

Unité de recherche INRIA Rennes : IRISA, Campus universitaire de Beaulieu - 35042 Rennes Cedex (France)Unité de recherche INRIA Rhône-Alpes : 655, avenue de l’Europe - 38334 Montbonnot Saint-Ismier (France)

Unité de recherche INRIA Rocquencourt : Domaine de Voluceau - Rocquencourt - BP 105 - 78153 Le Chesnay Cedex (France)

ÉditeurINRIA - Domaine de Voluceau - Rocquencourt, BP 105 - 78153 Le Chesnay Cedex (France)��������� ���� ���������� ��� ���

ISSN 0249-0803


Recommended