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Modèles D'habillage De Surface Pour La Synthèse D'images

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Modèles D'habillage De Surface Pour La Synthèse D'images Modèles d’habillage de surface pour la synthèse d’images. Sylvain Lefebvre To cite this version: Sylvain Lefebvre. Modèles d’habillage de surface pour la synthèse d’images.. Interface homme-machine [cs.HC]. Université Joseph-Fourier - Grenoble I, 2005. Français. tel-00012154 HAL Id: tel-00012154 https://tel.archives-ouvertes.fr/tel-00012154 Submitted on 18 Apr 2006 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Universite´ Joseph Fourier de Grenoble (UJF) Modeles` d'habillage de surface pour la synthese` d'images Sylvain LEFEBVRE These` present´ ee´ pour l'obtention du titre de Docteur de l'Universite´ Joseph Fourier Specialit´ e´ Informatique Arretˆ e´ Ministeriel´ du 5 juillet 1984 et du 30 mars 1992 Prepar´ ee´ au sein du laboratoire EVASION-GRAVIR/IMAG-INRIA. UMR CNRS C5527. Composition du jury : Fabrice NEYRET Directeur de these` Claude PUECH President´ du Jury Michael MCCOOL Rapporteur Mathias PAULIN Rapporteur Mark HARRIS Examinateur Jean–Michel DISCHLER Examinateur Przemek PRUNSINKIEWICZ Encadrant Eurodoc 1 Remerciements Mes premiers remerciements vont a` mes parents, Maryse et Jean-Claude Lefebvre, et a` ma famille, pour leur soutien et leurs encouragements sans faille. Mais je n'aurais que difficilement traverse´ ces trois annees´ sans ma compagne, Franc¸oise, qui m'a apporte´ aide, soutien, et bonheur au quotidien, malgre´ les nombreuses separations´ imposees´ par un emploi du temps trop charge´ et de nombreux voyages. Je remercie aussi tout particulierement` mon frere,` Stephane´ Lefebvre, a` qui je dois, entre–autre, ma passion pour les jeux videos,´ mes premiers pas de Basic et ma premiere` lecture, plus tard, du Richie–Kernighan. Je remercie eg´ alement Fabrice, pour m'avoir initie´ au monde de la recherche, pour sa dis- ponibilite,´ les nombreuses discussions et idees´ echang´ ees,´ et la liberte´ qu'il m'a permise durant ces trois annees´ de these.` Merci aussi a` Jean–Luc Koning, pour ses conseils precieux´ au travers de trois annees´ de monitorat a` l'ESISAR. Je souhaite eg´ alement remercier Przemek Prunsinkie- wicz, pour m'avoir accueilli a` l'Universite´ de Calgary dans d'excellentes conditions ; et Hugues Hoppe, pour m'avoir offert l'incroyable opportunite´ d'effectuer un stage, puis un postdoc a` Mi- crosoft Research. Mille mercis a` Jer´ omeˆ Decroix et Thomas Bruel, graceˆ a` qui j'ai decouv´ ert l'informatique graphique (POVray, les “coding party”), et qui m'ont beaucoup appris. C'est ensemble que nous avons mis les premieres` miettes de pizza dans nos claviers (tout un symbole !). Merci aussi a` Alexis Angelidis, graphiste et codeur de talent, avec qui nous avons passe´ de nombreux bons moments a` creer´ un raytracer, puis un jeu (Etees), puis a` nous detendre´ autour de quelques Gui- ness bien merit´ ees.´ Merci a` Samuel Hornus et a` Jerome´ Darbon pour les nombreuses aventures de “deadline” inoubliables, et les recherches menees´ ensemble ! Merci eg´ alement aux compagnons de these,` Stephane´ Grabli, Stephane´ Guy, Sylvain Paris et a` tous les thesards´ d'ARTIS et EVASION pour les bons moments et leur aide precieuse.´ Et puis bien surˆ , un grand merci aux equipes´ d'ARTIS et EVASION, pour quatre annees´ de bonne humeur, pauses cafe,´ discussions improvisees´ et pour toutes les choses, indenombrables,´ que j'ai apprises a` leurs cotˆ es.´ Merci en particulier a` Xavier Decoret, Lionel Reveret, Gilles De- bunne, Phillipe Decaudin, Joelle Thollot, pour leurs conseils et les nombreux echanges´ d'idees.´ Enfin, merci aux copains, Antoine, Philippe, Charly, Karine, Renaud, Lili, Eric, Vincent, Cindy pour les nombreuses soirees´ de detente.´ Un grand merci eg´ alement a` l'equipe´ du 17, Matthieu, Louis, Philippe, Cyril, Jean–Baptiste, pour les soirees´ autour du theme` du jeu video,´ les week–end “ShufflePuck Cafe” et les modeles` 3D et textures que le lecteur retrouvera dans ces pages ! 2 T a b l e d e s m a t i e` r e s I Introduction et etat´ de l'art 13 1 Introduction 15 1 Un probleme` de tapisserie . 17 2 Objectifs de la these` . 18 3 Contributions . 19 4 Organisation du document . 20 2 Etat de l'art 23 1 Rappel sur la creation´ d'images de synthese` . 23 1.1 Representation´ des formes . 23 1.2 Eclairage . 24 1.3 Algorithmes de rendu . 24 1.3.1 L'ecran´ . 24 1.3.2 Lancer de rayon . 24 1.4 Rendu projectif . 26 1.5 Modeles` d'illumination locale . 28 1.6 Moduler l'illumination locale avec un modele` d'habillage . 28 2 Modeles` d'habillage pour les surfaces quelconques . 30 2.1 Placage de texture standard, par parametrisation´ de surface . 30 2.1.1 Principe . 30 2.1.2 Parametrisation´ planaire . 30 2.1.3 Stockage des donnees´ de texture . 35 2.1.4 Acces` aux donnees´ de texture . 35 2.1.5 Interpolation . 35 2.1.6 Limitations du placage de texture . 37 2.1.7 Extensions du placage de texture . 40 2.2 Cartes d'environnement . 45 2.2.1 Principe . 45 2.2.2 Cartes d'environnement gen´ eralis´ ees´ . 46 2.2.3 Conclusion sur les cartes d'environnement . 47 2.3 Particules de textures . 48 2.3.1 Principe . 48 4 TABLE DES MATIERES` 2.3.2 Representations´ utilisees´ et difficultes´ . 48 2.4 Habillage en volume . 49 2.4.1 Principe . 49 2.4.2 Donnees´ d'habillage en volume . 50 3 Modeles` d'habillage pour les terrains . 52 3.1 Textures explicites . 52 3.2 Pavages periodiques´ du plan . 52 3.3 Pavages aperiodiques´ du plan . 53 3.4 Pavages de surfaces . 56 3.5 Quelques techniques utilisees´ dans le jeu video´ . 56 3.5.1 Melange´ de differentes´ echelles´ . 57 3.5.2 Transitions entre materiaux´ . 57 3.5.3 Ajout de hautes frequences´ . 58 4 Filtrage . 60 4.1 Origine du probleme` . 60 4.2 Sur–echantillonnage´ . 62 4.3 Filtrage et modeles` d'habillage . 62 4.3.1 Filtrage pour le placage de texture . 62 4.3.2 Filtrage et combinaison de textures explicites . 66 4.3.3 Filtrage des textures procedurales´ . 66 4.3.4 Filtrage des modeles` d'habillage en gen´ eral´ . 66 4.4 Note sur la qualite´ de filtrage . 67 4.5 Limites du filtrage pour les modeles` d'habillage . 67 4.5.1 Aliasing geom´ etrique´ . 67 4.5.2 Interaction avec le modele` d'eclairage´ . 68 5 Techniques de gen´ eration´ d'aspect de surface . 69 5.1 Techniques de peinture . 69 5.2 Synthese` de textures . 69 5.2.1 Textures procedurales´ . 70 5.2.2 Synthese` a` partir d'un echantillon´ . 71 5.2.3 Methodes´ basees´ sur la simulation . 73 5.3 Methodes´ respectant les contraintes des pavages . 73 5.4 Textures animees´ ou dynamiques . 74 6 Modeles` d'habillage et representations´ alternatives . 75 6.1 Textures Volumiques . 75 6.2 Imposteurs . 75 6.3 Rendu par point . 76 7 Concevoir des modeles` d'habillage pour les applications interactives . 77 7.1 Cartes accel´ eratrices´ . 77 7.2 Geom´ etrie´ et applications interactives . 79 8 Resum´ e´ et conclusion . 80 TABLE DES MATIERES` 5 II Habillage a` base de motifs pour terrains et surfaces parametr´ ees´ 83 3 Textures procedurales´ a` base de motifs 85 1 Notre approche : Textures procedurales´ a` base de motifs . 86 1.1 Cartes et textures . 88 1.2 Combiner les composants . 88 1.3 Composants pour le choix et le positionnement des motifs . 88 1.4 Transitions . 96 1.5 Animation . 99 2 Notes d'implementation´ . 102 2.1 Encodage des tables en 2D . 102 2.2 Encodage d'entiers dans des textures . 103 3 Connecter les composants pour gen´ erer´ des textures : etude´ de cas . 103 4 Filtrage des textures gen´ er´ ees´ . 108 4.1 Solutions pour nos textures procedurales´ . 108 4.2 Discussion sur l'interpolation . 110 5 Resultats´ . 111 6 Conclusion . 112 4 Application : rendu de gouttes d'eau sur surfaces 115 1 Positionnement des gouttes d'eau . 115 2 Texture d'humidite´ . 116 3 Rendu . 116 4 Conclusion . 117 5 Application : ombres portees´ par un grand ensemble d'objets 121 1 Le contexte . 121 1.1 Gen´ eration´ de la foretˆ . 122 1.1.1 Principe . 122 1.1.2 Le carre´ de foretˆ . 122 1.1.3 Creation´ des arbres a` partir des graines . 123 2 Ombres d'objets sur un terrain . 123 3 Conclusion . 127 III Textures de haute resolution´ plaquees´ sur surfaces quelconques 129 6 Gestion de textures de haute resolution´ plaquees´ sur des surfaces quelconques 131 1 Travaux sur le chargement progressif . 132 2 Organisation des donnees´ de texture . 134 3 Vue d'ensemble de notre architecture . ..
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