With the rapid expansion of the range of digital characters involved in film and game production, creating a wide variety of expressive characters has become a problem that cannot be solved efficiently through current animation methods. Key-frame animation is time-consuming and requires animation expertise. Motion capture is constrained by equipment and environment requirements and is most applicable to humanoid characters. Simulation can produce physically correct motion but does not account for expressiveness. This thesis focuses on developing a more efficient animation system using a procedural approach in which the skeletal structure and characteristics of motion that communicate weight and age in quadrupeds have been isolated and engineered as user-controlled tools and modifiers to build creature shape and synthesize cyclic gait animation. This new approach accomplished the goal of quick generation of expressive characters. It is also successful in achieving real-time animation playback and adjustment.

Studien gick ut på att undersöka huruvida animationskurvor kunde användas för att generera slagrörelser som var användbara i spel samt om dessa uppfattades som tilltalande av en publik. Det undersöktes även i vilken utsträckning animationskurvor och rörelsekurvor kan användas för att generalisera animationsfenomen. / The purpose of the study was to examine whether animation curves could be used to generate punching movements useful in games, and if an audience perceived these movements as appealing. It also held the purpose of investigating to which extent movement curves and animation curves can be used to generalize animation phenomena.

Procedural human motion generation is still an open area of research. Most research into procedural human motion focus on two problem areas: the realism of the generated motion and the computation time required to generate the motion. Realism is a problem because humans are very adept at spotting the subtle nuances of human motion and so the computer generated motion tends to look mechanical. Computation time is a problem because the complexity of the motion generation algorithms results in lengthy processing times for greater levels of realism. The balancing human problem poses the question of how to procedurally generate, in real-time, realistic standing poses of an articulated human body. This report presents the balancing human algorithm that addresses both concerns: realism and computation time. Realism was addressed by integrating two existing algorithms. One algorithm addressed the physics of the human motion and the second addressed the prediction of the next pose in the animation sequence. Computation time was addressed by identifying techniques to simplify or constrain the algorithms so that the real-time goal can be met. The research methodology involved three tasks: developing and implementing the balancing human algorithm, devising a real-time simulation graphics engine, and then evaluating the algorithm with the engine. An object-oriented approach was used to model the balancing human as an articulated body consisting of systems of rigid-bodies connected together with joints. The attributes and operations of the object-oriented model were derived from existing published algorithms.

Achieving a believable gait pattern for a virtual quadrupedal character requires a significant time investment from an animator. This thesis presents a prototype system for creating a foundational layer of natural-looking animation to serve as a starting point for an animator. Starting with video of an actual horse walking, joints are animated over the footage to create a rotoscoped animation. This animation represents the animal’s natural motion. Joint angle values for the legs are sampled per frame of the animation and conditioned for Fourier analysis. The Fast Fourier Transform provides frequency information that is used to create mathematical descriptions of each joint’s movement. A model representing the horse’s overall gait pattern is created once each of the leg joints has been analyzed and defined. Lastly, a new rig for a virtual quadruped is created and its leg joints are animated using the gait pattern model derived through the analysis.

Procedural animations are still in its infancy, and one of the techniques to create such is using Reinforcement Learning. In this project, swimming animations are created using UnityML version 0.6 with their Reinforcement Learning training agents, using the policy PPO, created by OpenAI. A humanoid character is placed in a simulated water environment and propels itself forward by rotating its joints. The force created depends on the joints mass and the scale of the rotation. The animation is then compared to a swimming animation created using movement capture data. It is concluded that the movement capture data animation is significantly more realistic than the one created in this project. The procedurally created animations displays many of the typical issues with reinforcement learning such as jittering and non-smooth motions. While the model is relatively simple, it is not possible to avoid these issues completely with more computational power in the form of a more complex model with more Degrees of Freedom. It is however possible to finetune the animations with the improvements listed at the end of the discussion. / Procedurellt skapade animationer är ett relativt nytt område som ständigt utvecklas och en av teknikerna för att skapa dessa är genom att använda sig av Reinforcement Learning. I detta projekt är animationer av simningsbeteenden skapade med hjälp av Unity’s plugin UnityML version 0.6, med hjälp av deras Reinforment Learning agenter och policyn PPO, skapad av OpenAI. En mänsklig karaktär är instantierad i en simulerad vattenmiljö och får sin rörelseförmåga genom att rotera sina lemmar, så som armar och ben, ihopkopplade med Unity’s jointkomponenter. Kraften skapad är baserad på lemmens massa och storleken av rotationen från en observation till den nästa. Större massa och rotation ger en större kraft. Ett animationsbeteende skapas av ett stort antal observationer och utförda krafter. Animationen jämförs sedan med en simningsanimation skapad med hjälp av referensdata från en människa. Den procedurellt skapade animationen visar sig vara betydligt mindre realistic än den skapad med hjälp av referensdata. Projektets skapade animation visar flera av de vanliga svagheterna hos animationer skapade med Reinforcement Learning så som överdrivna och hastiga rörelser. Även om modellen är relativt simpel skulle inte kvalitén på animationen förbättras betydelsefullt med en mer komplex modell med en högre Degree of Freedom. Det är däremot möjligt att förbättra animationen och eliminera många av felen i efterhand, något som beskrivs i diskussionen.

Animation of human walk is employed in many interactive applications, mostly in computer games. There are many ways to create such animation which differ in compromise among naturalness, control over animation and computing time. This work implements procedural animation which is applicable for walking on uneven terrain. Skeletal animation is used for manipulation with model of human body. Furthermore, inverse kinematics is described and implemented. That allows for adaptation to uneven terrain. It also describes phases of human walk, so we can accurately aproximate them. Proposed solution enables specification of walk using number of parameters and is able to adapt to surrounding terrain. The result should be usable in creation of computer games and should allow for creation of specific animation of human walk without need to create such animation manually.

When it comes to video games, immersion is key. All types of games aim to keep the player immersed in some form or another. A common aspect of the immersive world in most role-playing games -- but not exclusive to the genre -- is the non-playable character (NPC). At their best, NPCs play an integral role to the sense of immersion the player feels by behaving in a way that feels believable and fits within the world of the game. However, due to lack of innovation in this area of video games, at their worst NPCs can jar the player out of the immersive state of flow with unnatural behavior. In an effort towards making non-playable characters (NPCs) in games smarter, more believable, and more immersive, a method based in psychological theory for controlling the behavior of NPCs was developed. Based on a behavior model similar to most modern games, our behavior model for NPCs traverses a behavior tree. A novel method was introduced using the five-factor model of personality (also known as the big-five personality traits) and the circumplex model of affect (a model of emotion) to inform the traversal of the behavior tree of NPCs. This behavior model has two main beneficial outcomes. The first is emergent gameplay, resulting in unplanned, unpredictable experiences in games which feel closer to natural behavior, leading to an increase in immersion. This can be used for complex storytelling as well by offering information about an NPC's personality to be used in the narrative of games. Secondly, the model is able to provide the emotional status of an NPC in real time. This capability allows developers to programmatically display facial and body expression, eschewing the current time-consuming approach of artist-choreographed animation. Finally, a maze simulation environment was constructed to test the results of our behavior model and procedural animation. The data collected from 100 iterations in our maze simulation environment about our behavior model found that a correlation can be observed between traits and actions, showing that emergent gameplay can be achieved by varying personality traits. Additionally, by incorporating a novel method for procedural animation based on real-time emotion data, a more realistic representation of human behavior is achieved.

程序式動畫是一種根據使用者所提供的高階運動參數，自動產生動畫的方法。藉著高階的運動參數，程序式動畫比運動擷取資料有著更高的彈性。使用者可透過調整參數，輕易地讓動畫滿足情境上所需的限制。但如何調整適當的運動參數以產生擬真的動畫仍屬不易，因此程序式動畫常有在視覺上觀感不自然的問題。本研究的目標是，將運動擷取資料擬真的要素，帶到程序式動畫之中，以改進程序式動畫的品質。我們將問題定義成一個最佳化問題：給定一段運動擷取資料，系統該如何調整程序式動畫之參數，使得程序式動畫與運動擷取資料的差距盡可能地縮小？我們的系統可以參考一段運動擷取資料，以最佳化演算法，自動調整程序式動畫的參數，搜尋能產生出與運動擷取資料最為相似的運動參數。為了進一步讓產生之動畫符合環境的限制需求，多組最佳化過後的運動參數可以再透過內插，重新產生出一組符合限制需求的運動參數。實驗結果顯示，我們的方法不但使程序式動畫得以保留原來彈性的優點，也改善了程序式動畫常有的視覺觀感不自然的缺點。 / Procedural animation provides a way for a user to generate animation according to the high-level motion parameters that the user supplies. With the high-level motion parameters, procedural animation has the flexibility of generating animation accommodating the requested constraints in a scenario. However, tuning parameters to generate realistic animations usually is a difficult task. Therefore, animations produced with this approach often have the drawback of unrealistic-looking. Our goal is to improve the quality of procedural animation by bringing the naturalness of motion capture data into procedural animation. We model our problem as an optimization problem: given a motion captured clip, how does the system tune the motion parameters in an animation procedure to minimize the difference between animations produced by a procedure and captured in a motion clip? Our proposed system takes a motion captured clip as a reference and tunes the motion parameters of the animation procedure with an optimization algorithm. In order to generate animation satisfying environmental constraints, multiple optimized motion parameters can be interpolated to create a new set of motion parameters which can also satisfy the constraints. Our experimental results show that our method not only retains the flexibility of procedural animation, but also enhances the quality of procedural animation.

Att utveckla 3D-animeringar till dataspel är kostsamt eftersom det tar mycket tid och resurser för att uppnå den kvalitet som dagens spelare kräver. För att både spara arbetstid och göra det lättare för ovana animatörer att skapa animationer av tillräckligt hög kvalitet undersöker detta arbete hur ett verktyg för regelbaserad procedurell animering kan utformas, vad spelare anser om resultatet och vad utvecklare anser om både resultat och användning. För att testa detta skapades en artefakt (ett rymdspel) bestående av 3D-modeller och programmering (C# i Unity) av script, API, klasser och metoder. Arte­fakten animerar procedurellt utifrån algoritmer baserade på variabler. Utvärderingen av artefakten genomfördes med stöd av funktionsprotokoll, enkät och intervjuer. Slutsatsen är att regelbaserad procedurell animering är användbar för mekaniska delar utifrån synpunkter från dataspelsutvecklare och spelare. Framtida arbete kan bestå av en utökad undersökning med fler respondenter, tillförande av ett grafiskt gränssnitt, produktutveckling tillsammans med företag, skapande av fler verktyg och användade av AI.

Les créatures à n-pattes, comme les quadrupèdes, les arachnides ou les reptiles, sont une partie essentielle de n’importe quelle simulation et ils participent à rendre les mondes virtuels plus crédibles et réalistes. Ces créatures à n-pattes doivent être capables de se déplacer librement vers les points d’intérêt de façon réaliste, afin d’offrir une meilleure expérience immersive aux utilisateurs. Ces animations de locomotion sont complexes en raison d’une grande variété de morphologies et de modes de déplacement. Il convient d’ajouter à cette problématique la complexité des environnements où ils naviguent. Un autre défi lors de la modélisation de tels mouvements vient de la difficulté à obtenir des données sources. Dans cette thèse nous présentons un système capable de générer de manière procédurale des animations de locomotion pour des dizaines de créatures à n-pattes, en temps réel, sans aucune donnée de mouvement préexistante. Notre système est générique et contrôlable. Il est capable d’animer des morphologies différentes, tout en adaptant les animations générées à un environnement dynamique complexe, en temps réel, ce qui donne une grande liberté de déplacement aux créatures à n-pattes simulées. De plus, notre système permet à l’utilisateur de contrôler totalement l’animation produite et donc le style de locomotion / Multi-legged characters like quadrupeds, arachnids, reptiles, etc. are an essential part of any simulation and they greatly participate in making virtual worlds more life-like. These multi-legged characters should be capable of moving freely and in a believable way in order to convey a better immersive experience for the users. But these locomotion animations are quite rich due to the complexity of the navigated environments and the variety of the animated morphologies, gaits, body sizes and proportions, etc. Another challenge when modeling such animations arises from the lack of motion data inherent to either the difficulty to obtain them or the impossibility to capture them.This thesis addresses these challenges by presenting a system capable of procedurally generating locomotion animations fordozens of multi-legged characters in real-time and without anymotion data. Our system is quite generic thanks to the chosen Procedural-Based techniques and it is capable of animating different multi-legged morphologies. On top of that, the simulated characters have more freedom while moving, as we adapt the generated animations to the dynamic complex environments in real-time. Themain focus is plausible movements that are, at the same time,believable and fully controllable. This controllability is one of the forces of our system as it gives the user the possibility to control all aspects of the generated animation thus producing the needed style of locomotion