Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Sign Language is a fully-fledged natural language possessing its own syntax and grammar; a fact which implies that the problem of machine translation from a spoken source language to Sign Language is at least as difficult as machine translation between two spoken languages. Sign Language, however, is communicated in a modality fundamentally different from all spoken languages. Machine translation to Sign Language is therefore burdened not only by a mapping from one syntax and grammar to another, but also, by a non-trivial transformation from one communicational modality to another. With regards to the computer visualization of Sign Language; what is required is a three dimensional, temporally accurate, visualization of signs including both the manual and nonmanual components which can be viewed from arbitrary perspectives making accurate understanding and imitation more feasible. Moreover, given that facial expressions and movements represent a fundamental basis for the majority of non-manual signs, any system concerned with the accurate visualization of Sign Language must rely heavily on a facial animation component capable of representing a well-defined set of emotional expressions as well as a set of arbitrary facial movements. This thesis investigates the development of such a computer facial animation system. We address the problem of delivering coordinated, temporally constrained, facial animation sequences in an online environment using VRML. Furthermore, we investigate the animation, using a muscle model process, of arbitrary three-dimensional facial models consisting of multiple aligned NURBS surfaces of varying refinement. Our results showed that this approach is capable of representing and manipulating high fidelity three-dimensional facial models in such a manner that localized distortions of the models result in the recognizable and realistic display of human facial expressions and that these facial expressions can be displayed in a coordinated, synchronous manner. / AFRIKAANSE OPSOMMING: Gebaretaal is 'n volwaardige natuurlike taal wat oor sy eie sintaks en grammatika beskik. Hierdie feit impliseer dat die probleem rakende masjienvertaling vanuit 'n gesproke taal na Gebaretaal net so moeilik is as masjienvertaling tussen twee gesproke tale. Gebaretaal word egter in 'n modaliteit gekommunikeer wat in wese van alle gesproke tale verskil. Masjienvertaling in Gebaretaal word daarom nie net belas deur 'n afbeelding van een sintaks en grammatika op 'n ander nie, maar ook deur beduidende omvorming van een kommunikasiemodaliteit na 'n ander. Wat die gerekenariseerde visualisering van Gebaretaal betref, vereis dit 'n driedimensionele, tyds-akkurate visualisering van gebare, insluitend komponente wat met en sonder die gebruik van die hande uitgevoer word, en wat vanuit arbitrêre perspektiewe beskou kan word ten einde die uitvoerbaarheid van akkurate begrip en nabootsing te verhoog. Aangesien gesigsuitdrukkings en -bewegings die fundamentele grondslag van die meeste gebare wat nie met die hand gemaak word nie, verteenwoordig, moet enige stelsel wat te make het met die akkurate visualisering van Gebaretaal boonop sterk steun op 'n gesigsanimasiekomponent wat daartoe in staat is om 'n goed gedefinieerde stel emosionele uitdrukkings sowel as 'n stel arbitrre gesigbewegings voor te stel. Hierdie tesis ondersoek die ontwikkeling van so 'n gerekenariseerde gesigsanimasiestelsel. Die probleem rakende die lewering van gekordineerde, tydsbegrensde gesigsanimasiesekwensies in 'n intydse omgewing, wat gebruik maak van VRML, word aangeroer. Voorts word ondersoek ingestel na die animasie (hier word van 'n spiermodelproses gebruik gemaak) van arbitrre driedimensionele gesigsmodelle bestaande uit veelvoudige, opgestelde NURBS-oppervlakke waarvan die verfyning wissel. Die resultate toon dat hierdie benadering daartoe in staat is om hoë kwaliteit driedimensionele gesigsmodelle só voor te stel en te manipuleer dat gelokaliseerde vervormings van die modelle die herkenbare en realistiese tentoonstelling van menslike gesigsuitdrukkings tot gevolg het en dat hierdie gesigsuitdrukkings op 'n gekordineerde, sinchroniese wyse uitgebeeld kan word.

Generating natural phenomena in a virtual world has a number of practical applications. Thanks to the rich and complicated details in the real world, the goal of realistically and efficiently reproducing natural phenomena is well known as an open problem for graphics researchers. In this dissertation, three different issues in modeling liquid animations have been addressed. First, a virtual surface method is proposed to account for surface tension effects and their interactions with solid surfaces in physically based fluid simulation. This allows us to generate various surface tension behaviors in small scale liquid. The second issue that is addressed is how to make small scale fluid simulation more efficient. The proposed solution is a general shallow wave equation model, extended from the original shallow wave equations. By simplifying 3D incompressible fluid dynamics into 2D, small scale liquid can be stably and efficiently simulated over arbitrarily curved surfaces using implicit numerical schemes. The third contribution is a novel hybrid framework that combines image based reconstruction techniques with physically based fluid simulation. While image based methods cannot correctly generate fluid animations alone frame by frame, physics is used as a refinement tool to enforce physical soundness by propagating shape information back and forth in space and time. In this way, water animations can be realistically and faithfully generated from images without error accumulation or stability issues.

動作擷取法是現今相當受到歡迎的角色動作產生方法，而一般多是使用已擷取好的動作，以人工的方式將數個不同的動作混合以產生出所需的動作。但想要大量產生符合需求的混合動作仍相當不容易，因此有人提出了「動作圖」這個方法。動作圖是一種根據使用者所給定的動作擷取資料集合，經過自動化的計算找出各個動作資料之間可以連接的動作片段。藉由這個自動化的程序，各個動作擷取資料可以相互連接起來，達到在不同的動作間平順轉換，且同時保有原動作擷取資料擬真特性的目的。但縱使有上述的好處，目前動作圖的技術僅能就所擷取的全身動作進行串接，品質與彈性往往決定於一開始動作擷取資料的準備，因此如何讓既有的全身動作資料得以分解再利用，以發揮最大的價值，是一個重要的問題。在本研究中，我們提出了一個階層式的動作圖結構名為多層式動作圖，在這個多層式動作圖的結構中，我們將身體的動作區分成數個部位，分別計算各自的動作圖後再合併成一個多層式的架構，而合併的過程中我們提出「整體動作相似度」的計算方式，以做為兩個動作是否容易轉接的比較依據。我們也提出了在不同階層間動作圖運作的規則，以使計算的複雜度及系統的可用性取得合理的平衡。此外，我們更進一步提出名為Motion Script的簡易語意描述語言，來輔助控制這個具有高複雜度的動作圖結構。實驗的結果顯示，我們的方法可以即時根據使用者的指令，搜尋並產生出原動作資料所沒有的動作組合。與傳統的動作圖相比，我們的方法能更進一步的發揮原動作擷取資料的價值，以有系統的方式讓動作組合自動產生更具豐富性及彈性。 / Motion capture is a popular method for generating realistic character animation. In most applications, a motion usually is prepared by manually blending existing captured motion clips to generate a desired motion clip. However, finding a good transition points manually for two motion clips is a time-consuming task and cannot be scaled up easily. Motion Graph is a technique that has been proposed to automate this process by finding suitable connection points and the corresponding transition motions between motion data. With this automatic procedure, motions captured separately can be smoothly connected while keeping the realism of the captured motions. However, most motion graph techniques only consider the transition of full-body motions in two motion clips, and therefore, the resulting motion .depends on the variety of motions available in the motion database. It is an important issue to be able to compose new motion clips as much as possible with given motion capture database. In this research, we propose a hierarchical motion graph structure called Multi-Layered Motion Graph. In this structure, we divide motion data into layers of parts depending on the articulated structure of human body, and then compute a motion graph for each part of the motion. We then combine these motion graphs into an interconnected hierarchical structure. In order to facilitate the composition of motions for different parts from different motion clips, we propose a new metric called Overall Motion Similarity to find reasonable composition of motions in run time. We also propose several rules about how to traverse the motion graphs in different layers to generate feasible motions. Furthermore, we have designed a scripting language called Motion Script to facilitate the specification and search of desirable animation to be generated. Our experimental results reveal that our method is able to compose animations that the original motion graph cannot generate in real time. Compared to the traditional motion graph method, our method is able to make good use of existing motion capture library to compose new motions in a systematic way.

In the digital era, the comics medium has been transported from print to computer screen, and thus its evolution takes place in digital performances based on full-body interaction technologies. The major implication of this process is that the conventions of comics will be merging with those of performance, film, and animation. In a comics story implemented with full-body interaction technologies, representational space shifts from two to three dimensions. Physical elements can now easily be combined with virtual ones. The participants' contribution to the experience now includes a larger set of kinesthetic choices. Earlier media offer the readers the opportunity to read the story with their eyes, turn pages, and click a mouse. Instead of one or perhaps two readers of print and screen-based comics, a digital performance can be experienced by a group of viewers positioned in space in various ways. By utilizing the tools of computer vision, the projection of a participant can be made the main character of the comics story. Consequently, the comics and animation frame changes when moved to digital performance spaces. The frame becomes embodied, nested, elastic, and dynamic. The first two qualities relate to the physicality of the medium, where performers and viewers are simultaneously present in both the real and fictional spaces. The second two qualities relate to the procedurality of the medium and the potential for computational manipulation within the frame based on changing relationships across space (distance) and time (story).

Dans cette recherche, nous étudions les problèmes de modélisation de discontinuités topologiques d'objets physiques déformables. Parmi toutes les discontinuités topologiques possibles, nous nous intéressons à celles que nous avons qualifiées de « discontinuités de 1 vers N » dans le contexte de la modélisation physique. Entrent dans cette catégorie les phénomènes de fractures, de cassures, de déchirures et de fissures. De nombreux travaux se sont intéressés à la modélisation et la simulation de ce type de phénomènes. Plusieurs méthodes ont été proposées, à partir de systèmes de modélisation différents parmi lesquels les plus courants sont : modélisation masses – ressorts sur maillages, méthodes d'éléments finis avec et sans maillage. Une question commune qui se pose dans toutes les méthodes discutées dans cette thèse est la question des endroits fonctionnels où apparaissent et se propagent les discontinuités topologiques. Nous étudions ce problème à travers plusieurs approches sur la modélisation physique de discontinuités topologiques. Nous proposons ensuite notre approche, qui se fonde sur le formalisme masses – interactions. Nous montrons en quoi ce type de modélisation offre certaines propriétés natives pour traiter cette question. En particulier, le fait qu'elles soient par principe affranchies de toute notion de contigüité spatiale et de continuité matérielle leur permet de poser de manière très générale la question des changements d'état physique à l'origine des discontinuités topologiques observées. Nous montrons qu'une très grande majorité de changements d'états physiques peuvent se modéliser par des variations des paramètres physiques d'interactions physiques non linéaires en lieu et place de changements structurels adoptés dans majorité des travaux menés par des méthodes courante et qui conduisent à des modifications très importantes et complexes du modèle physique. Néanmoins, cela induit, des effets d'enlèvements de matière aux endroits du changement d'état puisque celui –ci est porté par l'interaction, c'est à dire une contrainte physique qui est placée entre les points matériels. Pour s'affranchir de ces effets, nous proposons alors une nouvelle méthode, qui consiste à modéliser les discontinuités topologiques sur un élément de masse physique et non pas sur un élément de contrainte physique. Nous appelons ce dispositif « MAT éclatable ». Le processus de modélisation avec les MAT éclatables s'inscrit dans le processus de modélisation masses-interactions tel que défini dans le formalisme de modélisation et de simulation de CORDIS – ANIMA. La méthode proposée permet d'effectuer des changements topologiques par modèle physique par changements structurels, mais différemment de ceux plus couramment effectuées dans les méthodes usuelles (tels que par exemple, ajout ou suppression de ressorts ou de masses), la méthode des MAT éclatables permet de maîtriser le fonctionnement du modèle physique en termes d'optimalité des transformations, de stabilité du temps de calcul et de stabilité numérique. La méthode des MAT éclatables a été développée sous forme d'un dispositif de modélisation, destiné aux utilisateurs de notre outil de modélisation CORDIS-ANIMA. Pour illustrer et valider la méthode, nous proposons un ensemble de modèles physiques modélisation des fractures et déchirures multiples apparaissant et se propageant dans des objets très déformables, des effilochures, ou des fragmentations. / L'auteur n'a pas fourni de résumé en anglais

Popular fiction books describe rich visual environments that contain characters, objects, and behaviour. This research develops automated processes for converting text sourced from fiction books into animated virtual environments and multi-modal films. This involves the analysis of unrestricted natural language fiction to identify appropriate visual descriptions, and the interpretation of the identified descriptions for constructing animated 3D virtual environments. The goal of the text analysis stage is the creation of annotated fiction text, which identifies visual descriptions in a structured manner. A hierarchical rule-based learning system is created that induces patterns from example annotations provided by a human, and uses these for the creation of additional annotations. Patterns are expressed as tree structures that abstract the input text on different levels according to structural (token, sentence) and syntactic (parts-of-speech, syntactic function) categories. Patterns are generalized using pair-wise merging, where dissimilar sub-trees are replaced with wild-cards. The result is a small set of generalized patterns that are able to create correct annotations. A set of generalized patterns represents a model of an annotator's mental process regarding a particular annotation category. Annotated text is interpreted automatically for constructing detailed scene descriptions. This includes identifying which scenes to visualize, and identifying the contents and behaviour in each scene. Entity behaviour in a 3D virtual environment is formulated using time-based constraints that are automatically derived from annotations. Constraints are expressed as non-linear symbolic functions that restrict the trajectories of a pair of entities over a continuous interval of time. Solutions to these constraints specify precise behaviour. We create an innovative quantified constraint optimizer for locating sound solutions, which uses interval arithmetic for treating time and space as contiguous quantities. This optimization method uses a technique of constraint relaxation and tightening that allows solution approximations to be located where constraint systems are inconsistent (an ability not previously explored in interval-based quantified constraint solving). 3D virtual environments are populated by automatically selecting geometric models or procedural geometry-creation methods from a library. 3D models are animated according to trajectories derived from constraint solutions. The final animated film is sequenced using a range of modalities including animated 3D graphics, textual subtitles, audio narrations, and foleys. Hierarchical rule-based learning is evaluated over a range of annotation categories. Models are induced for different categories of annotation without modifying the core learning algorithms, and these models are shown to be applicable to different types of books. Models are induced automatically with accuracies ranging between 51.4% and 90.4%, depending on the category. We show that models are refined if further examples are provided, and this supports a boot-strapping process for training the learning mechanism. The task of interpreting annotated fiction text and populating 3D virtual environments is successfully automated using our described techniques. Detailed scene descriptions are created accurately, where between 83% and 96% of the automatically generated descriptions require no manual modification (depending on the type of description). The interval-based quantified constraint optimizer fully automates the behaviour specification process. Sample animated multi-modal 3D films are created using extracts from fiction books that are unrestricted in terms of complexity or subject matter (unlike existing text-to-graphics systems). These examples demonstrate that: behaviour is visualized that corresponds to the descriptions in the original text; appropriate geometry is selected (or created) for visualizing entities in each scene; sequences of scenes are created for a film-like presentation of the story; and that multiple modalities are combined to create a coherent multi-modal representation of the fiction text. This research demonstrates that visual descriptions in fiction text can be automatically identified, and that these descriptions can be converted into corresponding animated virtual environments. Unlike existing text-to-graphics systems, we describe techniques that function over unrestricted natural language text and perform the conversion process without the need for manually constructed repositories of world knowledge. This enables the rapid production of animated 3D virtual environments, allowing the human designer to focus on creative aspects.

Orientador: Prof. Dr. João Paulo Gois / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência da Computação, 2017. / Uma tarefa difícil para animadores é redesenhar modelos 2D para cada nova visão ou pose. Como consequência, várias aplicações têm sido propostas para tornar este processo mais fácil. Uma abordagem bem sucedida é a técnica de Modelagem Cartoon 2.5D. O objetivo desta ténica é automatizar o cálculo de novas visões ¿ pela simulação da rotação global 3D ¿ a partir de entradas 2D fornecidas pelo usuário. No entanto, os trabalhos anteriores de modelos 2.5D não apresentam esquemas para criar novas poses de maneira eficiente, i.e., o usuário redesenha as visões de entrada novamente na nova pose. Para esta finalidade, nós apresentamos uma nova abordagem que permite ao usuário criar novas visões e novas poses para os modelos 2.5D. Criamos uma estrutura hierárquica de ossos que explora a metodologia de modelos 2.5D, garantindo a coerência entre a estrutura de ossos e o modelo. A usabilidade da técnica apresentada é intuitiva, especialmente para usuários já familiarizados com outras ferramentas 2.5D. / A laborious task for animators is to redesign of 2D models for each new required view or pose. As a consequence, several applications have been proposed to make this task easier. A successful approach is the Cartoon 2.5D Models. Its goal is to automaticaly produce new views (by the simulation of 3D global rotation) from userprovided 2D models. However, previous works of 2.5D Models does not have support to calculate poses efficiently, i.e., the user redraws the input views again in the new pose. We present a novel approach that allows the user to produce both new views and poses easily for the 2.5D Models, thus puppeteering the 2.5D Models. It makes use of a hierarchical bone structure that explores the methodology of the 2.5D Models, ensuring coherence between the bone structures and the model. The usability of our approach is intuitive, especially for the users acquainted with previous 2.5D Modeling tools.

Técnicas baseadas em física têm chamado a atenção da comunidade de computação gráfica, em especial para animação de fluidos (gás ou líquidos). As técnicas tradicionais para animação de fluidos são metodologias top-down baseadas em malhas 2D/3D, tais como Diferenças Finitas e Elementos Finitos, em conjunto com equações de fluidos Navier-Stokes. Entretanto, tais métodos têm um custo computacional alto. Uma alternativa é o uso de técnicas baseadas em Autômatos Celulares do tipo Lattice Gas (LGCA) e o Método de Lattice Boltzmann (LBM). A idéia básica desses métodos consiste em obter a dinâmica macroscópica de um fluido a partir do comportamento coletivo de diversas partículas microscópicas. Em geral, tais metodologias bottom-up são eficientes do ponto de vista computacional. Neste trabalho, são estudados os aspectos teóricos e práticos da animação computacional de fluidos bidimensionais para computação gráfica, usando um método LGCA chamado FHP, e um método LBM chamado D2Q9. É proposto um modelo de fluido 3D baseado nos modelos bidimensionais FHP e D2Q9, bem como em métodos de interpolação. Em seguida, são apresentadas duas aplicações para animação de fluidos através dos métodos mencionados, uma para execução em tempo real e outra para execução off-line. Nos resultados dos experimentos computacionais são enfatizados a simplicidade e o potencial dos modelos propostos quando combinados com técnicas eficientes de rendering. / Physically-based techniques for the animation of fluids (gas or liquids) have taken the attention of the computer graphics community. The traditional fluid animation methods rely on a top down viewpoint that uses 2D/3D mesh based approaches motivated by the Eulerian methods of Finite Element (FE) and Finite Difference (FD), in conjunction with Navier-Stokes equations of fluids. Alternatively, lattice methods comprised by the Lattice Gas Cellular Automata (LGCA) and Lattice Boltzmann (LBM) can be used. The basic idea behind these methods is that the macroscopic dynamics of a fluid is the result of the collective behavior of many microscopic particles. Such bottom-up approaches need low computational resources for both the memory allocation and the computation itself. In this work, we consider animation of fluids for computer graphics applications, using a LGCA method called FHP, and a LBM method called D2Q9, both bidimensional models. We propose 3D fluid animation techniques based on the FHP and D2Q9 as well as interpolation methods. Then, we present two animating frameworks based on the mentioned lattice methods, one for a real time implementation and the other for an off-line implementation. In the experimental results we emphasize the simplicity and power of the presented models when combined with efficient techniques for rendering and compare their efficiency.

Orientadores: José Mario De Martino, Harlen Costa Batagelo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-16T06:00:13Z (GMT). No. of bitstreams: 1 Reis_ClausiusDuqueGoncalves_M.pdf: 10846415 bytes, checksum: 37318c89ce60ddb5bce4efd57c86abd9 (MD5) Previous issue date: 2010 / Resumo: A modelagem e animação de rugas faciais têm sido tarefas desafiadoras, devido à variedade de conformações e sutilezas de detalhes que as rugas podem exibir. Neste trabalho, são descritos dois métodos de apresentação de rugas em tempo real, utilizando as modernas GPUs. Ambos os métodos são baseados no uso de shaders em GPU e em uma abordagem de normal mapping para aplicar rugas sobre modelos virtuais. O primeiro método utiliza áreas de influência descritas por mapas de textura para calcular a exibição de rugas sobre o modelo, controlados por um "Vetor de Ativação", que informa ao shader a visibilidade das rugas em cada uma das áreas de influência. O segundo método apresenta rugas nos modelos faciais, utilizando as informações de deslocamento dos vértices em direções pré-definidas, informadas através de um "Vetor Direção de Rugas", que informa o sentido que o deslocamento de um vértice causa o surgimento de rugas / Abstract: The modeling and animation of facial wrinkles have been challenging tasks, due to the variety of conformations and detail subtleness that the wrinkles can display. In this paper, we describe two methods to present wrinkles in real time, using modern GPUs. Both methods are based on the use of GPU shaders and a normal mapping approach to apply wrinkles on virtual models. The first method uses influence areas described by texture maps to calculate the display of wrinkles on the model, controlled by an "Activation Vector", which tells the shader the appearance of wrinkles in each area of influence. The second method presents wrinkles on facial models using the vertex displacement information in predetermined directions, informed by a "Wrinkles Direction Vector", informing the direction that the displacement of a vertex causes the presentation of wrinkles / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica e de Computação

Over the past few decades there have emerged greater possibilities for users and consumers of media to create or engage in the creation of digital media technologies. This PhD dissertation explores the ways in which the broadening of possibilities for making technologies, specifically software, has been taken advantage of by new producers of digital culture – freelancers, aspiring digital media creators and small studios – in the production of digital visual media. It is based on two empirical case studies that concern the making of free software for computer graphics animation production in two contexts: by a loose collective of anime fans in Siberia, Russia, and by a small animation studio in Amsterdam, Netherlands. The case studies are presented and analysed in the scope of four journal articles and one book chapter which form the core of the dissertation. The dissertation draws on a media practice perspective and an understanding of software as an artefact that concentrates and mediates specific infrastructural arrangements that entangle politics of technological production, economic interests and practice-related concerns. The analytical focus of the research problematises in particular practices of software decommodification and its further repair and development by non-programmers; the anchoring of software development and repair in actual production practices of computer graphics animations; and a commitment to sharing software, animations and other artefacts online as commons. The thesis combines several concepts from anthropology and science and technology studies to theorise these practices: – politics and regimes of value (Appadurai, 1986); repair and artful integrations (Jackson, 2014; Suchman, 2000); gifting (Baudrillard, 1981; Mauss, 1925/2002) and autonomy (cf Bourdieu, 1993). Bringing together these concepts, the dissertation regards them as constitutive and indicative of what I refer to as ‘media-related infrastructuring practices’, or practices in which non-programmers generate infrastructures through creating and mediating arrangements around technical artefacts like software. The results of the dissertation indicate how making free software for computer graphics media is entangled in diverse conditions of technological unevenness that may enable, but also limit, the possibilities of aspiring media creators to improve their status or work positions in the broader field of digital media. / Under det senaste decenniet har nya medieteknologier för kommunikationoch digitalt skapande möjliggjort för såväl professionella medieproducentersom amatörer att skapa och sprida olika typer av medieinnehåll. Samtidigt finns fler möjligheter än tidigare att bidra till utvecklingen av digitala medieteknologer, såsom programvaruverktyg och infrastrukturer för att producera och cirkulera medieinnehåll (t.ex. Coleman, 2013; Kannengießer,2016; Kubitschko, 2017; Löwgren and Reimer, 2013; Ratto, 2011; Rosneroch Fox, 2016; Toombs et al., 2014). Denna avhandling undersöker hur dessa ökade möjligheter för skapandet av teknologier och infrastrukturer för digital medieproduktion, i synnerhet programvara, har tagits tillvara av mediekreatörer som arbetar, eller strävar efter att arbeta, med datorgrafik. Avhandlingen fokuserar på kulturella, teknologiska och ekonomiska praktiker genom vilka frilansare, oetablerade mediekreatörer och mindre produktionsbolag skapar användardrivna programvaror. Med användardriven avser jag programvara som utvecklas av dess användare: digitalkonstnärer, amatörer och professionellaskapare av digitalt visuell media, snarare än de industriella producenter som traditionellt satt de tekniska ramarna för medieproduktion. Avhandlingen baseras på två empiriska fallstudier som rör skapandet av fri programvara för datoranimation. Med fri programvara avses program där användarna har frihet att använda, kopiera, distribuera, studera, ändra och förbättra programvaran (GNUProject, 2017). De huvudsakliga forskningsfrågorna är: a) hur skapare av datorgrafik utvecklar, formar och guidarde fria programvaror som utgör ett alternativ till industriella programvarorför digital animation, och b) vilken mening dessa alternativ tillskrivs när de används i medieproduktion. Den första fallstudien fokuserar på arbetet av Blender Institute, en oberoende animationsstudio i Amsterdam, Nederländerna. Sedan 2006 har studion arbetat med att utveckla och förbättra en populär programvara för 3D-animation, Blender. Detta har skett genom skapandet av så kallade ‘open-source animation films’, korta animerade filmer med höga produktionsvärden genom vilka programvara, filmelement och utbildning i programvaranhar delats online. Genom den här fallstudien har jag diskuterat programvaruutveckling i en kontext av delningsekonomi. Jag har visat hur strategiskt delande kan vara ett sätt att erövra en maktposition inom digitalmedieproduktion. Jag har också belyst de olika spänningar som uppstår när kulturproducenter söker förena olika perspektiv på programvaror, individuella ambitioner och existerande marknadsstrukturer. Den andra fallstudien fokuserar på praktikerna av Morevna project, ett kollektiv av animé-fans, geografiskt situerade i staden Gorno-Altaysk, i ryska Sibirien. Kollektivet har skapat korta datoranimerade filmer genom vilka man utforskat, lagat och distribuerat den fria programvara de använt i sina produktioner: Synfig för 2D animering. I denna fallstudie har jag argumenterat för värdet av att undersöka spänningar, misslyckanden och lagning snarare än innovationer för att förstå hur alternativa infrastrukturerför digital medieproduktion kan uppstå i kontexter starkt präglade av piratverksamhet. Fallstudierna presenteras och analyseras i fyra olika tidskriftsartiklar och ett bokkapitel, som alla ingår i denna avhandling. De tre första artiklarna svarar mot den första forskningsfrågan och de två sista artiklarna mot den andra. Metodologiskt utgår avhandlingen ifrån kvalitativa ansatser, såsom grounded theory och etnografi. Det empiriska materialet har samlats inmellan 2012 och 2016. Som en del av fältarbetet har jag genomfört kvalitativaintervjuer med 37 informanter. Bland dessa ingår skapare av datorgrafikoch animationer, programmerare och projektledare på Blender Institute och i Morevna. Teoretiskt utgår avhandlingen från ett perspektiv på medier som praktik (Couldry, 2004, 2012). Specifika praktiker som analyseras och teoretiseras i artiklarna är dekommodifiering av programvara; förankrandet av lagningav programvara i medieproduktion; samt delning online av programvara, filmer och filmmaterial; produktionsarbete; samt utbildningsmaterial. Praktikerna analyseras genom begreppen politics and regimes of value (Appadurai, 1986); repair och artful integrations (Jackson, 2014; Suchman,2000); och gifting (Baudrillard, 1981; Mauss, 1925/2002). Jag har också utgått från begreppet autonomi (jfr. Bourdieu, 1993) för att utforska frågan om meningsproduktion vid utveckling av användardriven fri programvaraför medieproduktion. Begreppen beskriver hur olika relationer upprätthålls mellan digitala artefakter, ekonomi och personer. Jag förenar dem i ett gemensamt teoretiskt ramverk genom begreppet infrastructuring (Karasti och Syrjänen, 2004) från science and technology studies. Genom detta begrepp vidgar jag perspektivet på medier som praktik med fokus på praktiker där icke-programmerare och amatörer skapar digitala infrastrukturer genom att integrera nya verktyg och teknik med socialt praktik. Resultaten av denna studie visar hur skapandet av fri programvara av frilansare, oetablerade mediekreatörer och mindre produktionsbolag är ett sätt att skapa infrastrukturell trygghet på en osäker arbetsmarknad. Olika former av autonomi förhandlas i relation till olika konfigurationer av infrastrukturer för teknikproduktion och distribution, till exempel infrastrukturerför piratkopiering eller för att komma runt industriellt skapade begränsningar i förändringen av programvara. I linje med Jackson (2014) betonar jag vikten av att väga upp diskursen kring ‘användarinnovation’ (von Hippel, 2005) genom att betrakta misslyckanden, förfall och haverier som en del av processen av att utveckla nya medier och ny medieteknik, och på så sätt omförhandla uppdelningen och hierarkin mellan olika medieproducenter. Programvaruförfall, dekommodifiering och åldrande kan göra programvaror till ‘residual media’ (Acland, 2007), som i sig kan fungera som en plats där mening, värde och maktförhållanden omförhandlas och skapas på nytt. Dessa omförhandlingar är inte sprungna ur snabba och spontana förändringsprocesser möjliggjorda genom nätverk av kommunikationsteknologier. Snarare karakteriseras de av långsamhet (Paper 3), strategi, dolt kapital (Paper 2), samt konstant förhandling mellan olika intressen (Paper 1, 4 och 5). Litteratur som behandlar organisationen av öppen medieproduktion baserad på allmänningar såsom fri programvara och digitala artefakter som delas online har ofta beskrivits som något som utvecklas organiskt när de frikopplats från etablerade upphovsrättsformer (t.ex. Benkler, 2006; Shirky, 2009). Denna avhandling visar dock att det krävs strategiskt och långsiktigt engagemang för att skapa och etablera en programvara, engagera grupper av användare och integrera programvaran i aktuell medieproduktion. Dessutom antas det ofta att det är hackare, programmerare eller ingenjörer som har makten att tänka ut och realisera faktiska infrastrukturer för digital medieproduktion. Denna studie visardock att mikroanställningar och retorik gör det möjligt även för användare att initiera och påverka medieteknikutvecklingen (Paper 5). Genom att anlägga ett perspektiv på medier som praktik och utveckla det perspektivet med begreppet infrastructuring till det jag kallar för ‘mediarelated infrastructuring practices’ har jag visat hur användardriven programvara och infrastrukturer för datografik skapas och stabiliseras genom att skapa nya och integrera existerande resurser i det digitala medielandskapet. Detta perspektiv öppnar upp möjligheter för att etablera kopplingar mellan olika delfält inom medievetenskapen som fokuserar på medieproduktion, såsom studier av industriell medieproduktion; amatördriven öppenteknikproduktion; samt studier av medieinfrastruktur. Genom infrastructuring kan man se hur medieproducenter skapar nya, förändrar och kritiserar existerande arbetsrelationer, ekonomiska relationer samt kunskapsrelationer. Dessutom kan det växande fältet av infrastrukturstudierutvecklas genom att byta fokus från studier av stora etablerade medieinfrastrukturertill processer av pågående infrastrukturformering av mindre och nya aktörer i det digitala medielandskapet. Sammanfattningsvis bidrar denna avhandling med empiriskt material vilket skapar en större förståelse för formeringen av delar av de digitalamedieproduktionsinfrastrkturer genom en analys av skapandet av användardrivenfri programvara för digital animation. Den bidrar också teoretiskt till en utveckling av perspektivet på medier som praktik (Couldry, 2012). Metodologiskt bidrar den genom att betona värdet av platsbaserad deltagande observation och etnografi även i sammanhang av decentraliserad medieproduktionspraktik. Den bidrar även till att skapa en större förståelse för produktionen av tekniken som underbygger och möjliggör de visuella uttrycken som präglar det mesta av vårt digitala medieinnehållsutbud idag.