Posing 3D Models from Drawing

Inferring the 3D pose of a character from a drawing is a complex and under-constrained problem. Solving it may help automate various parts of an animation production pipeline such as pre-visualisation. In this paper, a novel way of inferring the 3D pose from a monocular 2D sketch is proposed. The proposed method does not make any external assumptions about the model, allowing it to be used on different types of characters. The inference of the 3D pose is formulated as an optimisation problem and a parallel variation of the Particle Swarm Optimisation algorithm called PARAC-LOAPSO is utilised for searching the minimum. Testing in isolation as well as part of a larger scene, the presented method is evaluated by posing a lamp, a horse and a human character. The results show that this method is robust, highly scalable and is able to be extended to various types of models

RealitySketch: Embedding Responsive Graphics and Visualizations in AR through Dynamic Sketching

We present RealitySketch, an augmented reality interface for sketching interactive graphics and visualizations. In recent years, an increasing number of AR sketching tools enable users to draw and embed sketches in the real world. However, with the current tools, sketched contents are inherently static, floating in mid air without responding to the real world. This paper introduces a new way to embed dynamic and responsive graphics in the real world. In RealitySketch, the user draws graphical elements on a mobile AR screen and binds them with physical objects in real-time and improvisational ways, so that the sketched elements dynamically move with the corresponding physical motion. The user can also quickly visualize and analyze real-world phenomena through responsive graph plots or interactive visualizations. This paper contributes to a set of interaction techniques that enable capturing, parameterizing, and visualizing real-world motion without pre-defined programs and configurations. Finally, we demonstrate our tool with several application scenarios, including physics education, sports training, and in-situ tangible interfaces.Comment: UIST 202

Interfaces for human-centered production and use of computer graphics assets

L'abstract è presente nell'allegato / the abstract is in the attachmen

Ensimmäisen persoonan immersiivinen animaatiotyökalu

Computer-generated animation has an important role in both video game and film industry. 3D computer animation is generally done with 2D devices, such as the computer mouse, that are not optimal for that kind of use. To use them efficiently in 3D, long training periods are needed. This makes them especially inefficient in novice hands. Additionally, 2D display devices, such as the computer monitor, are unable to give the user depth perception. Therefore the user has to rely on perspective projection. The goal of this thesis was to create an animation tool, which provides the user a 3D view of the objects of interest and the user can manipulate the objects with his own hands in virtual space. This should be quite natural for users, because humans have lived their whole lives in a 3D world. The tool was developed and tested in collaboration with professional game industry animators. The tool uses an Oculus Rift DK2 device to give the user a 3D view with 6 DOF head tracking. The hand tracking is done with a Leap Motion controller, which is mounted in front of the Oculus Rift device. The software was programmed using the Unity game engine. According to the results there are uses for this sort of a tool especially in the first rough posing phases. The hand tracking quality still has something to improve, but even at the current level it can increase productivity in certain parts of the workflow.Tietokoneella luotu animaatio on tärkeässä osassa videopeli- ja elokuvateollisuudessa. Kolmiulotteisia tietokoneanimaatioita tehdään yleisesti kaksiulotteisilla laitteilla, kuten hiirellä, jotka eivät ole optimaalisia tähän käyttöön. Niiden käyttäminen tehokkaasti vaatii pitkää harjoittelua, joten ne ovat tehottomia etenkin vasta-alkajien käsissä. Kaksiulotteiset näyttölaitteet eivät myöskään pysty antamaan syvyysvaikutelmaa, joten käyttäjät joutuvat tyytymään perspektiiviprojektioon. Tämän diplomityön tarkoituksena oli luoda animaatiotyökalu, jonka avulla animaattori näkee hahmon kolmiulotteisena ja voi muokata sen asentoa omin käsin perinteisen nukkeanimaation tapaan. Tämän pitäisi olla hyvin luontevaa, koska ihmiset ovat oppineet elämään kolmiulotteisessa maailmassa. Työkalu kehitettiin yhteistyössä peliteollisuudessa työskentelevien animaattoreiden kanssa. Työkalu käyttää Oculus Rift DK2 -laitetta antaakseen käyttäjälle kolmiulotteisen näkymän ja kuuden vapausasteen liikkeentunnistuksen pään asennoille. Käsien liikettä seurataan Leap Motion -ohjaimella. Työkalun ohjelmointi tehtiin Unity-pelimoottoria käyttäen. Tuloksien perusteella tämän kaltaisella työkalulla olisi käyttöä etenkin karkeassa alkuvaiheen sommittelussa. Käsienseurantalaitteen tarkkuudessa on vielä parantamisen varaa, mutta nykytasollakin pystyy tehostamaan tiettyjä kohtia työnkulusta

Multi-touch Detection and Semantic Response on Non-parametric Rear-projection Surfaces

The ability of human beings to physically touch our surroundings has had a profound impact on our daily lives. Young children learn to explore their world by touch; likewise, many simulation and training applications benefit from natural touch interactivity. As a result, modern interfaces supporting touch input are ubiquitous. Typically, such interfaces are implemented on integrated touch-display surfaces with simple geometry that can be mathematically parameterized, such as planar surfaces and spheres; for more complicated non-parametric surfaces, such parameterizations are not available. In this dissertation, we introduce a method for generalizable optical multi-touch detection and semantic response on uninstrumented non-parametric rear-projection surfaces using an infrared-light-based multi-camera multi-projector platform. In this paradigm, touch input allows users to manipulate complex virtual 3D content that is registered to and displayed on a physical 3D object. Detected touches trigger responses with specific semantic meaning in the context of the virtual content, such as animations or audio responses. The broad problem of touch detection and response can be decomposed into three major components: determining if a touch has occurred, determining where a detected touch has occurred, and determining how to respond to a detected touch. Our fundamental contribution is the design and implementation of a relational lookup table architecture that addresses these challenges through the encoding of coordinate relationships among the cameras, the projectors, the physical surface, and the virtual content. Detecting the presence of touch input primarily involves distinguishing between touches (actual contact events) and hovers (near-contact proximity events). We present and evaluate two algorithms for touch detection and localization utilizing the lookup table architecture. One of the algorithms, a bounded plane sweep, is additionally able to estimate hover-surface distances, which we explore for interactions above surfaces. The proposed method is designed to operate with low latency and to be generalizable. We demonstrate touch-based interactions on several physical parametric and non-parametric surfaces, and we evaluate both system accuracy and the accuracy of typical users in touching desired targets on these surfaces. In a formative human-subject study, we examine how touch interactions are used in the context of healthcare and present an exploratory application of this method in patient simulation. A second study highlights the advantages of touch input on content-matched physical surfaces achieved by the proposed approach, such as decreases in induced cognitive load, increases in system usability, and increases in user touch performance. In this experiment, novice users were nearly as accurate when touching targets on a 3D head-shaped surface as when touching targets on a flat surface, and their self-perception of their accuracy was higher

3DCGキャラクタの表現の改善法と実時間操作に関する研究

早大学位記番号:新8176早稲田大

Animation de personnages 3D par le sketching 2D

Free-form animation allows for exaggerated and artistic styles of motions such as stretching character limbs and animating imaginary creatures such as dragons. Creating these animations requires tools flexible enough to shape characters into arbitrary poses, and control motion at any instant in time. The current approach to free-form animation is keyframing: a manual task in which animators deform characters at individual instants in time by clicking-and-dragging individual body parts one at a time. While this approach is flexible, it is challenging to create quality animations that follow high-level artistic principles---as keyframing tools only provide localized control both spatially and temporally. When drawing poses and motions, artists rely on different sketch-based abstractions that help fulfill high-level aesthetic and artistic principles. For instance, animators will draw textit{lines of action} to create more readable and textit{expressive} poses. To coordinate movements, animators will sketch textit{motion abstractions} such as semi-circles and loops to coordinate a bouncing and rolling motions. Unfortunately, these drawing tools are not part of the free-form animation tool set today. The fact that we cannot use the same artistic tools for drawing when animating 3D characters has an important consequence: 3D animation tools are not involved in the creative process. Instead, animators create by first drawing on paper, and only later are 3D animation tools used to fulfill the pose or animation. The reason we do not have these artistic tools (the line of action, and motion abstractions) in the current animation tool set is because we lack a formal understanding relating the character's shape---possible over time---to the drawn abstraction's shape. Hence the main contribution of this thesis is a formal understanding of pose and motion abstractions (line of action and motion abstractions) together with a set of algorithms that allow using these tools in a free-form setting. As a result, the techniques described in this thesis allow exaggerated poses and movements that may include squash and stretch, and can be used with various character morphologies. These pose and animation drafting tools can be extended. For instance, an animator can sketch and compose different layers of motion on top of one another, add twist around strokes, or turning the strokes into elastic ribbons. The main contributions of this thesis are summarized as follows: -The line of action facilitating expressive posing by directly sketching the overall flow of the character's pose. -The space-time curve allowing to draft full coordinated movements with a single stroke---applicable to arbitrary characters. -A fast and robust skeletal line matching algorithm that supports squash-and-stretch. -Elastic lines of action with dynamically constrained bones for driving the motion of a multi-legged character with a single moving 2D line.L'animation expressive permet des styles de mouvements exagerés et artistiques comme l'étirement de parties du corps ou encore l'animation de créatures imaginaires comme un dragon. Créer ce genre d'animation nécessite des outils assez flexible afin de déformer les personnages en des poses quelconques, ainsi que de pouvoir contrôler l'animation à tout moment dans le temps. L'approche acutelle pour l'animation expressive est le keyframing: une approche manuelle avec laquelle les animateurs déforment leur personnage un moment spécifique dans le temps en cliquand et glissant la souris sur une partis spécifique du corps---un à la fois. Malgré le fait que cette approche soit flexible, il est difficile de créer des animations de qualité qui suivent les principes artistiques, puisque le keyframing permet seulement qu'un contrôle local spatiallement et temporellement. Lorsqu'ils dessinent des poses ou des mouvements, les artistes s'appuient sur différentes abstractions sous forme de croquis qui facillitent la réalisation de certain principes artistiques. Par example, certains animateurs dessinent des lignes d'action afin de créer une pose plus lisible et expressive. Afin de coordonner un mouvement, les animateurs vont souvent dessiner des abstractions de mouvement comme des demi-cercles pour des sauts, ou des boucles pour des pirouettes---leur permettant de pratiquer la coordination du mouvement. Malheureusement, ces outils artistiques ne font pas partis de l'ensemble d'outils de keyframing actuelle. Le fait que l'on ne puisse pas employer les même outils artistiques pour animater des personnages 3D a une forte conséquence: les outils d'animation 3D ne sont pas employés dans le processus créatif. Aujourd'hui, les animateurs créent sur du papier et utilisent le keyframing seulement à la fin pour réaliser leur animation. La raison pour laquelle nous n'avons pas ces outils artistiques (ligne d'action, abstractions de mouvement) en animation 3D, est parce qu'il manque une compréhension formelle de ceux-ci qui nous permettrais d'exprimer la forme du personnage---potentiellement au cours du temps---en fonction de la forme de ces croquis. Ainsi la contribution principale de cette thèse est une compréhension formelle et mathématique des abstractions de forme et de mouvement courrament employées par des artistes, ainsi qu'un ensemble d'algorithme qui permet l'utilisation de ces outils artistiques pour créer des animations expressives. C'est-à-dire que les outils développés dans cette thèse permettent d'étirer des parties du corps ainsi que d'animer des personnages de différentes morphologies. J'introduis aussi plusieurs extentions à ces outils. Par example, j'explore l'idée de sculpter du mouvement en permettant à l'artiste de dessigner plusieurs couches de mouvement une par dessus l'autre, de twister en 3D les croquis, ou encore d'animer un croquis ligne comme un élastique. Les contributions principales de cette thèse, aussi résumé ci-dessous: -La ligne d'action facilitant la création de poses expressives en dessinant directement le flow complet du personnage. -La courbe spatio-temporelle qui permet de spécifier un mouvement coordoné complet avec un seul geste (en dessinant une seule courbe), applicable à n'importe quel personnage 3D. -Un algorithme de matching rapide et robuste qui permet du ``squash and stretch''. -La ligne d'action élastique avec des attachements dynamiques à la ligne permettant d'animer un personnages à plusieurs jambes (bras) avec une seule ligne 2D animée

Animation de personnages 3D par le sketching 2D

Free-form animation allows for exaggerated and artistic styles of motions such as stretching character limbs and animating imaginary creatures such as dragons. Creating these animations requires tools flexible enough to shape characters into arbitrary poses, and control motion at any instant in time. The current approach to free-form animation is keyframing: a manual task in which animators deform characters at individual instants in time by clicking-and-dragging individual body parts one at a time. While this approach is flexible, it is challenging to create quality animations that follow high-level artistic principles---as keyframing tools only provide localized control both spatially and temporally. When drawing poses and motions, artists rely on different sketch-based abstractions that help fulfill high-level aesthetic and artistic principles. For instance, animators will draw textit{lines of action} to create more readable and textit{expressive} poses. To coordinate movements, animators will sketch textit{motion abstractions} such as semi-circles and loops to coordinate a bouncing and rolling motions. Unfortunately, these drawing tools are not part of the free-form animation tool set today. The fact that we cannot use the same artistic tools for drawing when animating 3D characters has an important consequence: 3D animation tools are not involved in the creative process. Instead, animators create by first drawing on paper, and only later are 3D animation tools used to fulfill the pose or animation. The reason we do not have these artistic tools (the line of action, and motion abstractions) in the current animation tool set is because we lack a formal understanding relating the character's shape---possible over time---to the drawn abstraction's shape. Hence the main contribution of this thesis is a formal understanding of pose and motion abstractions (line of action and motion abstractions) together with a set of algorithms that allow using these tools in a free-form setting. As a result, the techniques described in this thesis allow exaggerated poses and movements that may include squash and stretch, and can be used with various character morphologies. These pose and animation drafting tools can be extended. For instance, an animator can sketch and compose different layers of motion on top of one another, add twist around strokes, or turning the strokes into elastic ribbons. The main contributions of this thesis are summarized as follows: -The line of action facilitating expressive posing by directly sketching the overall flow of the character's pose. -The space-time curve allowing to draft full coordinated movements with a single stroke---applicable to arbitrary characters. -A fast and robust skeletal line matching algorithm that supports squash-and-stretch. -Elastic lines of action with dynamically constrained bones for driving the motion of a multi-legged character with a single moving 2D line.L'animation expressive permet des styles de mouvements exagerés et artistiques comme l'étirement de parties du corps ou encore l'animation de créatures imaginaires comme un dragon. Créer ce genre d'animation nécessite des outils assez flexible afin de déformer les personnages en des poses quelconques, ainsi que de pouvoir contrôler l'animation à tout moment dans le temps. L'approche acutelle pour l'animation expressive est le keyframing: une approche manuelle avec laquelle les animateurs déforment leur personnage un moment spécifique dans le temps en cliquand et glissant la souris sur une partis spécifique du corps---un à la fois. Malgré le fait que cette approche soit flexible, il est difficile de créer des animations de qualité qui suivent les principes artistiques, puisque le keyframing permet seulement qu'un contrôle local spatiallement et temporellement. Lorsqu'ils dessinent des poses ou des mouvements, les artistes s'appuient sur différentes abstractions sous forme de croquis qui facillitent la réalisation de certain principes artistiques. Par example, certains animateurs dessinent des lignes d'action afin de créer une pose plus lisible et expressive. Afin de coordonner un mouvement, les animateurs vont souvent dessiner des abstractions de mouvement comme des demi-cercles pour des sauts, ou des boucles pour des pirouettes---leur permettant de pratiquer la coordination du mouvement. Malheureusement, ces outils artistiques ne font pas partis de l'ensemble d'outils de keyframing actuelle. Le fait que l'on ne puisse pas employer les même outils artistiques pour animater des personnages 3D a une forte conséquence: les outils d'animation 3D ne sont pas employés dans le processus créatif. Aujourd'hui, les animateurs créent sur du papier et utilisent le keyframing seulement à la fin pour réaliser leur animation. La raison pour laquelle nous n'avons pas ces outils artistiques (ligne d'action, abstractions de mouvement) en animation 3D, est parce qu'il manque une compréhension formelle de ceux-ci qui nous permettrais d'exprimer la forme du personnage---potentiellement au cours du temps---en fonction de la forme de ces croquis. Ainsi la contribution principale de cette thèse est une compréhension formelle et mathématique des abstractions de forme et de mouvement courrament employées par des artistes, ainsi qu'un ensemble d'algorithme qui permet l'utilisation de ces outils artistiques pour créer des animations expressives. C'est-à-dire que les outils développés dans cette thèse permettent d'étirer des parties du corps ainsi que d'animer des personnages de différentes morphologies. J'introduis aussi plusieurs extentions à ces outils. Par example, j'explore l'idée de sculpter du mouvement en permettant à l'artiste de dessigner plusieurs couches de mouvement une par dessus l'autre, de twister en 3D les croquis, ou encore d'animer un croquis ligne comme un élastique. Les contributions principales de cette thèse, aussi résumé ci-dessous: -La ligne d'action facilitant la création de poses expressives en dessinant directement le flow complet du personnage. -La courbe spatio-temporelle qui permet de spécifier un mouvement coordoné complet avec un seul geste (en dessinant une seule courbe), applicable à n'importe quel personnage 3D. -Un algorithme de matching rapide et robuste qui permet du ``squash and stretch''. -La ligne d'action élastique avec des attachements dynamiques à la ligne permettant d'animer un personnages à plusieurs jambes (bras) avec une seule ligne 2D animée

Tangent-space optimization for interactive animation control

Character animation tools are based on a keyframing metaphor where artists pose characters at selected keyframes and the software automatically interpolates the frames inbetween. Although the quality of the interpolation is critical for achieving a fluid and engaging animation, the tools available to adjust the result of the automatic inbetweening are rudimentary and typically require manual editing of spline parameters. As a result, artists spend a tremendous amount of time posing and setting more keyframes. In this pose-centric workflow, animators use combinations of forward and inverse kinematics. While forward kinematics leads to intuitive interpolations, it does not naturally support positional constraints such as fixed contact points. Inverse kinematics can be used to fix certain points in space at keyframes, but can lead to inferior interpolations, is slow to compute, and does not allow for positional contraints at non-keyframe frames. In this paper, we address these problems by formulating the control of interpolations with positional constraints over time as a space-time optimization problem in the tangent space of the animation curves driving the controls. Our method has the key properties that it (1) allows the manipulation of positions and orientations over time, extending inverse kinematics, (2) does not add new keyframes that might conflict with an artist's preferred keyframe style, and (3) works in the space of artist editable animation curves and hence integrates seamlessly with current pipelines. We demonstrate the utility of the technique in practice via various examples and use cases.</jats:p

Shadows, touch and digital puppeteering: a media archaeological approach

Aims The practical aim of this research project is to create a multi-touch digital puppetry system that simulates shadow theatre environments and translates gestural acts of touch into live and expressive control of virtual shadow figures. The research is focussed on the qualities of movement achievable through the haptics of single and multi-touch control of the digital puppets in the simulation. An associated aim is to create a collaborative environment where multiple performers can control dynamic animation and scenography, and create novel visualisations and narratives. The conceptual aim is to link traditional and new forms of puppetry seeking cultural significance in the ‘remediation’ of old forms that avail themselves of new haptic resources and collaborative interfaces. The thesis evaluates related prior art where traditional worlds of shadow performance meet new media, digital projection and 3D simulation, in order to investigate how changing technical contexts transform the potential of shadows as an expressive medium. Methodology The thesis uses cultural analysis of relevant documentary material to contextualise the practical work by relating the media archaeology of 2D puppetry—shadows, shadowgraphs and silhouettes—to landmark work in real-time computer graphics and performance animation. The survey considers the work of puppeteers, animators, computer graphics specialists and media artists. Through practice and an experimental approach to critical digital creativity, the study provides practical evidence of multiple iterations of controllable physics-based animation delivering expressive puppet motion through touch and multiuser interaction. Video sequences of puppet movement and written observational analysis document the intangible aspects of animation in performance. Through re-animation of archival shadow puppets, the study presents an emerging artistic media archaeological method. The major element of this method has been the restoration of a collection of Turkish Karagöz Shadow puppets from the Institut International de la Marionnette (Charleville, France) into a playable digital form. Results The thesis presents a developing creative and analytical framework for digital shadow puppetry. It proposes a media archaeological method for working creatively with puppet archives that unlock the kinetic and expressive potential of restored figures. The interaction design introduces novel approaches to puppetry control systems—using spring networks—with objects under physics-simulation that demonstrate emergent expressive qualities. The system facilitates a dance of agency¹ between puppeteer and digital instrument. The practical elements have produced several software iterations and a tool-kit for generating elegant, nuanced multi-touch shadow puppetry. The study presents accidental discoveries—serendipitous benefits of open-ended practical exploration. For instance: the extensible nature of the control system means novel input—other than touch—can provide exciting potential for accessible user interaction, e.g. with gaze duration and eye direction. The study also identifies limitations including the rate of software change and obsolescence, the scope of physics-based animation and failures of simulation. Originality/value The work has historical value in that it documents and begins a media archaeology of digital puppetry, an animated phenomenon of increasing academic and commercial interest. The work is of artistic value providing an interactive approach to making digital performance from archival material in the domain of shadow theatre. The work contributes to the electronic heritage of existing puppetry collections. The study establishes a survey of digital puppetry, setting a research agenda for future studies. Work may proceed to digitise, rig and create collaborative and web-mediated touch-based motion control systems for 2D and 3D puppets. The present study thus provides a solid platform to restore past performances and create new work from old, near forgotten-forms. ¹ Following Andrew Pickering, puppetry is ‘a temporally extended back-and-forth dance of human and non-human agency in which activity and passivity on both sides are reciprocally intertwined’ PICKERING, A. 2010. Material Culture and the Dance of Agency. In: BEAUDRY, M. C. & HICKS, D. (eds.) Oxford Handbook of Material Culture Studies. Oxford University Press.