Une simulation du comportement d’une nu\u00c3\u00a9e d’oiseaux en vol.<\/p>\n
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Un incroyable et bien r\u00c3\u00a9el vol d’\u00c3\u00a9tourneaux :<\/p>\n
<\/iframe><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" id=\"image2451\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2012\/09\/pixel_gris.gif\" alt=\"Grey line\" width=\"482\" height=\"1\" \/><\/p>\n<p><a href=\"http:\/\/www.red3d.com\/cwr\/boids\/\">Craig Reynolds<\/a> est expert en intelligence artificielle appliqu\u00c3\u00a9e \u00c3\u00a0 l’image num\u00c3\u00a9rique. Il a (entre autres) collabor\u00c3\u00a9 au film <a href=\"http:\/\/en.wikipedia.org\/wiki\/Tron_%28film%29\">Tron<\/a> et \u00c3\u00a0 <a href=\"http:\/\/en.wikipedia.org\/wiki\/Batman_Returns\">Batman returns<\/a>. Il travaille aujourd’hui chez <a href=\"http:\/\/www.research.scea.com\/\">Sony Computer Entertainment US Research and Development<\/a>, centre de recherche d\u00c3\u00a9di\u00c3\u00a9 notamment \u00c3\u00a0 la recherche d’applications pour la Playsation 3 et les futures plateformes de Sony Entertainment.<\/p>\n<p>Il y a quelques ann\u00c3\u00a9es de cela, Craig Reynolds r\u00c3\u00a9alisa dans le cadre de son travail de d\u00c3\u00a9veloppement chez Symbolics Inc. un programme contr\u00c3\u00b4lant le mouvement individuel d’oiseaux (repr\u00c3\u00a9sent\u00c3\u00a9s par des triangles) et qu’il appela <em>bo\u00c3\u00afds<\/em> (birds en langage enfantin). Apr\u00c3\u00a8s quelques exp\u00c3\u00a9riences complexes et peu concluantes, il s’inspira des th\u00c3\u00a9ories du chaos et programma quelques r\u00c3\u00a8gles simples inspir\u00c3\u00a9es par des sp\u00c3\u00a9cialistes de l’\u00c3\u00a9tude des vols d’oiseaux :<\/p>\n<li>maintenir une distance minimale avec les objets pr\u00c3\u00a9sents dans l’environnement, ainsi qu’avec les autres oiseaux. <\/li>\n<li>adapter sa vitesse \u00c3\u00a0 celle des oiseaux situ\u00c3\u00a9s dans le voisinage. <\/li>\n<li>se d\u00c3\u00a9placer vers le centre per\u00c3\u00a7u de la masse des oiseaux pr\u00c3\u00a9sents dans le voisinage.<\/li>\n<p>Pour corser la situation, Craig Reynolds introduisit dans le paysage des colonnes jouant le r\u00c3\u00b4le d’obstacles, avec la r\u00c3\u00a8gle suivante : si un \u00ab\u00a0bo\u00c3\u00afd\u00a0\u00bb arrive de face, il prend la tangente. Si c’est impossible (chance infime), il la percute, tombe \u00c3\u00a0 sa base, puis doit voler plus vite pour rattraper ses cong\u00c3\u00a9n\u00c3\u00a8res. <\/p>\n<p><img decoding=\"async\" id=\"image431\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/boids_colonnes_482.gif\" alt=\"boids_colonnes_482.gif\" \/><\/p>\n<p>Une fois ces quelques r\u00c3\u00a8gles fix\u00c3\u00a9es, il observa lors de l’ex\u00c3\u00a9cution du programme une situation totalement impr\u00c3\u00a9vue. Un comportement quasi \u00e2\u20ac\u0153vivant\u00e2\u20ac\u0153 d’un <em>bo\u00c3\u00afd<\/em> : le vol harmonieux et impr\u00c3\u00a9visible des <em>bo\u00c3\u00afds<\/em> s’approcha des colonnes. <\/p>\n<p>La majorit\u00c3\u00a9 des triangles se faufila \u00c3\u00a0 travers elles en prenant les tangentes, en se divisant en sous-groupes ou en acc\u00c3\u00a9l\u00c3\u00a9rant leur vol. Mais un seul <em>bo\u00c3\u00afd<\/em>, arrivant dans une trajectoire improbable de collision, hors de toute tangente possible, percuta une colonne. Il tomba \u00c3\u00a0 terre, fit le tour de la colonne et rattrapa \u00e2\u20ac\u0153\u00c3\u00a0 tire d’aile\u00e2\u20ac\u0153 les autres <em>bo\u00c3\u00afds<\/em> qui poursuivaient leur vol ! Une situation non programm\u00c3\u00a9e \u00c3\u00a0 \u00c3\u00a9merg\u00c3\u00a9 des contraintes et du comportement collectif des individus. Le programme a \u00e2\u20ac\u0153invent\u00c3\u00a9\u00e2\u20ac\u0153 une solution \u00c3\u00a0 une situation particuli\u00c3\u00a8re. <\/p>\n<p>Le plus \u00c3\u00a9tonnant est qu’ind\u00c3\u00a9pendamment de la r\u00c3\u00a9partition ou la dispersion des <em>bo\u00c3\u00afds<\/em> au d\u00c3\u00a9part de la simulation, un vol group\u00c3\u00a9 se constitue \u00c3\u00a0 chaque exp\u00c3\u00a9rience, bien que la formation \u00ab\u00a0vol group\u00c3\u00a9\u00a0\u00bb ne soit programm\u00c3\u00a9e dans aucun individu.<\/p>\n<p><img decoding=\"async\" id=\"image430\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/boids1_482.jpg\" alt=\"boids1_482.jpg\" \/><\/p>\n<p>Le travail de Craig Reynolds a inspir\u00c3\u00a9 de nombreuses d\u00c3\u00a9clinaisons. Ce type de simulation est \u00c3\u00a9videmment adaptable \u00c3\u00a0 des groupes de diverses natures : bancs de poissons, essaims d’insectes ou autres troupeaux d’animaux. <\/p>\n<p>Dans le domaine de l’animation comportementale, il faut citer le travail majeur de <a href=\"http:\/\/en.wikipedia.org\/wiki\/Karl_Sims\">Karl Sims<\/a>, pionnier, chercheur et artiste en particules et vie artificielle. Karl Sims a remport\u00c3\u00a9 deux \u00ab\u00a0Golden Nicas\u00a0\u00bb au Festival Ars Electronica de Linz, avec <a href=\"http:\/\/www.aec.at\/de\/archives\/prix_archive\/prix_projekt.asp?iProjectID=2420\">Panspermia en 1991<\/a> et avec <a href=\"http:\/\/www.aec.at\/de\/archives\/prix_archive\/prix_projekt.asp?iProjectID=2424\">Liquid Selves \/ Primordial Dance en 1992.<\/a> <\/p>\n<p>Ses films sont t\u00c3\u00a9l\u00c3\u00a9chargeables sur archive.org :<\/p>\n<li>Evolved virtual creatures (1994) :<br \/>\n<a href=\"http:\/\/www.archive.org\/details\/sims_evolved_virtual_creatures_1994\">http:\/\/www.archive.org\/details\/sims_evolved_virtual_creatures_1994<\/a><\/li>\n<li>Liquid Selves (1992) :<br \/>\n<a href=\"http:\/\/www.archive.org\/details\/sims_liquid_selves_1992\">http:\/\/www.archive.org\/details\/sims_liquid_selves_1992<\/a><\/li>\n<li>Primordial Dance (1991) :<br \/>\n<a href=\"http:\/\/www.archive.org\/details\/sims_primordial_dance_1991\">http:\/\/www.archive.org\/details\/sims_primordial_dance_1991<\/a><\/li>\n<li>Panspermia (1990) :<br \/>\n<a href=\"http:\/\/www.archive.org\/details\/sims_panspermia_1990\">http:\/\/www.archive.org\/details\/sims_panspermia_1990<\/a><\/li>\n<li>Particle Dreams (1988) :<br \/>\n<a href=\"http:\/\/www.archive.org\/details\/sims_particle_dreams_1988\">http:\/\/www.archive.org\/details\/sims_particle_dreams_1988<\/a><\/li>\n<p>Plus r\u00c3\u00a9cemment, le travail de <a href=\"http:\/\/en.wikipedia.org\/wiki\/Jeffrey_Ventrella\">Jeffrey Ventrella<\/a> est \u00c3\u00a9galement \u00c3\u00a0 noter dans le domaine de la vie artificielle. Son site contient de nombreux programmes t\u00c3\u00a9l\u00c3\u00a9chargeables.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" id=\"image2451\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2012\/09\/pixel_gris.gif\" alt=\"Grey line\" width=\"482\" height=\"1\" \/><\/p>\n<p><strong>LIENS.<\/strong><\/p>\n<p><strong><em>Bo\u00c3\u00afds<\/em> de Craig Reynolds :<\/strong><\/p>\n<li><a href=\"http:\/\/www.red3d.com\/cwr\/boids\/\">http:\/\/www.red3d.com\/cwr\/boids\/<\/a><\/li>\n<p><strong><em>OpenSteer<\/em>, librairie C++ de Craig Reynolds<\/strong><br \/>\nd\u00c3\u00a9di\u00c3\u00a9e aux comportements directionnels d’individus\/objets : <\/p>\n<li><a href=\"http:\/\/opensteer.sourceforge.net\/\">http:\/\/opensteer.sourceforge.net\/<\/a><\/li>\n<li><a href=\"http:\/\/www.red3d.com\/cwr\/steer\/\">http:\/\/www.red3d.com\/cwr\/steer\/<\/a><\/li>\n<p><strong><em>A boids experiment<\/em> de Matt Mays <\/strong><br \/>\nbas\u00c3\u00a9 sur le pseudocode de <a href=\"http:\/\/www.vergenet.net\/~conrad\/boids\/\">Conrad Parker<\/a> et sur le code de <a href=\"http:\/\/www.behaviorworks.com\/people\/ckline\/boids\">Christopher Kline<\/a> (source C++ t\u00c3\u00a9l\u00c3\u00a9chargeable) :<\/p>\n<p><img decoding=\"async\" id=\"image436\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/matt_mays_482.jpg\" alt=\"matt_mays_482.jpg\" \/><\/p>\n<li><a href=\"http:\/\/switch.sjsu.edu\/nextswitch\/switch_engine\/front\/front.php?artc=287\">http:\/\/switch.sjsu.edu\/nextswitch\/switch_engine\/front\/front.php?artc=287<\/a>\n<\/li>\n<p><strong><em>C++ Boids<\/em> de Christopher Kline<\/strong><br \/>\n(objets C++ t\u00c3\u00a9l\u00c3\u00a9chargeables) :<\/p>\n<p><img decoding=\"async\" id=\"image437\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/christopher_kline_482.gif\" alt=\"christopher_kline_482.gif\" \/><\/p>\n<li><a href=\"http:\/\/www.behaviorworks.com\/people\/ckline\/boids\">http:\/\/www.behaviorworks.com\/people\/ckline\/boids<\/a><\/li>\n<p><strong><em>Swarm<\/em> de Daniel Shiffman <\/strong><br \/>\nest une installation vid\u00c3\u00a9o qui impl\u00c3\u00a9mente un pattern de vol d’oiseau inspir\u00c3\u00a9 de Boids de Craig Reynolds adapt\u00c3\u00a9 au mouvement constant d’un \u00ab\u00a0pinceau\u00a0\u00bb, un peu \u00c3\u00a0 la mani\u00c3\u00a8re du \u00ab\u00a0dripping\u00a0\u00bb Jackson Pollock, autre inspiration de Daniel Shiffman :<\/p>\n<p><img decoding=\"async\" id=\"image438\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/swarm3_482.jpg\" alt=\"swarm3_482.jpg\" \/><\/p>\n<li><a href=\"http:\/\/www.shiffman.net\/projects\/swarm\/\">http:\/\/www.shiffman.net\/projects\/swarm\/<\/a><\/li>\n<p><strong><em>Bo\u00c3\u00afds<\/em> de Poul Henriksen <\/strong><br \/>\n(source Java t\u00c3\u00a9l\u00c3\u00a9chargeable) :<\/p>\n<p><img decoding=\"async\" id=\"image435\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/poul-henriksen_482.gif\" alt=\"poul-henriksen_482.gif\" \/><\/p>\n<li><a href=\"http:\/\/www.greenfoot.org\/scenarios\/index.html\">http:\/\/www.greenfoot.org\/scenarios\/index.html<\/a><\/li>\n<p><strong><em>Vie Artificielle, o\u00c3\u00b9 la biologie rencontre l’informatique<\/em>,<br \/>\nillustr\u00c3\u00a9 avec Java par Jean-Philippe Rennard<\/strong><br \/>\n(source Java comment\u00c3\u00a9e t\u00c3\u00a9l\u00c3\u00a9chargeable) : <\/p>\n<p><img decoding=\"async\" id=\"image434\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/rennard_boids_482.gif\" alt=\"rennard_boids_482.gif\" \/><\/p>\n<li><a href=\"http:\/\/www.rennard.org\/iva\/boids.html\">http:\/\/www.rennard.org\/iva\/boids.html<\/a><\/li>\n<p><strong><em>eFloys<\/em> de Ariel Dolan<\/strong><br \/>\n(source Java t\u00c3\u00a9l\u00c3\u00a9chargeable et description des algorithmes) :<\/p>\n<p><img decoding=\"async\" id=\"image433\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/ariel_dolan_482.jpg\" alt=\"ariel_dolan_482.jpg\" \/><\/p>\n<li><a href=\"http:\/\/www.aridolan.com\/ofiles\/eFloys.html\">http:\/\/www.aridolan.com\/ofiles\/eFloys.html<\/a><\/li>\n<p><strong><em>Bo\u00c3\u00afds<\/em> de Conrad Parker<\/strong><br \/>\n(source Java t\u00c3\u00a9l\u00c3\u00a9chargeable et description des algorithmes) :<\/p>\n<p><img decoding=\"async\" id=\"image432\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2007\/03\/conrad_parker_482.gif\" alt=\"conrad_parker_482.gif\" \/><\/p>\n<li><a href=\"http:\/\/www.vergenet.net\/~conrad\/boids\/\">http:\/\/www.vergenet.net\/~conrad\/boids\/<\/a><\/li>\n<li><a href=\"http:\/\/www.vergenet.net\/~conrad\/boids\/pseudocode.html\">http:\/\/www.vergenet.net\/~conrad\/boids\/pseudocode.html<\/a><\/li>\n<p><img loading=\"lazy\" decoding=\"async\" id=\"image2451\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2012\/09\/pixel_gris.gif\" alt=\"Grey line\" width=\"482\" height=\"1\" \/><\/p>\n<p><em>Cours ‘Arts num\u00c3\u00a9riques – Atelier’<br \/>\nErg (\u00c3\u2030cole de Recherche Graphique) 2006-2007, P\u00c3\u00b4le Art.<br \/>\nProfesseur : Marc Wathieu. <\/em><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" id=\"image2451\" src=\"http:\/\/www.multimedialab.be\/blog\/wp-content\/uploads\/2012\/09\/pixel_gris.gif\" alt=\"Grey line\" width=\"482\" height=\"1\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Une simulation du comportement d’une nu\u00c3\u00a9e d’oiseaux en vol.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,32,30],"tags":[],"class_list":["post-439","post","type-post","status-publish","format-standard","hentry","category-code","category-generatif","category-sciences"],"_links":{"self":[{"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=\/wp\/v2\/posts\/439","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=439"}],"version-history":[{"count":8,"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=\/wp\/v2\/posts\/439\/revisions"}],"predecessor-version":[{"id":3142,"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=\/wp\/v2\/posts\/439\/revisions\/3142"}],"wp:attachment":[{"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=439"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=439"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.multimedialab.be\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=439"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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