近年來由於電腦軟硬體及人機介面介面技術的發展，互動數位敘事(Interactive Digital Storytelling, IDS)的應用也逐漸被重視，特別是在新型態電腦遊戲的設計，而這個趨勢也為即時虛擬攝影機的規劃帶來新的機會與挑戰。本研究旨在透過互動數位敘事腳本內容的分析，建置客製化攝影機運鏡實驗平台，即時自動產生符合情境情節、人物情緒的拍攝方式，並參考電影拍攝手法，結合攝影學的專業知識加入不同拍攝風格，讓同一段影片可以有不同的風格效果。我們希望能夠讓現有的互動敘事系統The Theater [1]中的運鏡技術有跡可循，不再只是以人工的方式憑藉直覺來設定攝影機的位置，而能使得虛擬攝影機的操控變得簡易，修正拍攝效果時將更加簡便，成功快速掌握運鏡的每一個細節。我們在The Theater的實驗平台之上，讓敘事者可以根據故事情境客製化虛擬攝影機的拍攝手法，並由電腦自動產生合宜的攝影機拍攝位置，快速完成攝影機規劃。我們以實例透過實驗的方式驗證此系統的有效性。 / The recent advances in computing technologies and human-computer interactions have attracted much attention in the development of interactive digital storytelling (IDS), especially in the application of novel computer game design. This trend does not only bring new opportunities but also new technological challenges to virtual camera planning. Our research in this work aims at building an experimental platform for customized virtual camera planning through the analysis of screen play in an in-teractive story. By adopting the domain knowledge of camera controls in existing films, we hope to design a computer-assisted system that allows an author to easily experiment with different styles of virtual cameras in a same story. We proposed to design an experimental platform based on “The Theater” IDS, which currently uses a pre-authored way to specify the camera position. In the proposed system, we allow an author to quickly customize virtual camera taking according to the context of a story fragment and let the computer generate appropriate camera configurations automati-cally. We use an example story to verify the effectiveness of the system through ex-periments.

[pt] Ao contar uma história, o narrador usa toda sua habilidade para entreter a audiência. Esta tarefa não define apenas o ato de contar uma história, mas também a capacidade de compreender as reações do público durante a narração da história. Não é muito difícil adaptar uma história para um único individuo baseando-se em suas preferências e escolhas anteriores, porém, a tarefa de escolher o que é melhor para um grupo torna-se bastante complicada. A seleção por votação de uma maioria pode não ser eficiente pois descarta alternativas que foram consideradas secundárias por alguns indivíduos, mas que funcionariam melhor para o grupo em questão. Desta forma, a seleção descuidada dos eventos em uma história poderia causar a ruptura do grupo, fazendo com que algumas pessoas desistam de continuar assistindo pois não foram agradadas. Esta tese propõe uma metodologia para criar histórias adaptadas para a audiência com base em traços de personalidade e preferências de cada indivíduo. Como uma audiência pode ser composta de indivíduos com preferências semelhantes ou mistas, é necessário considerar uma solução de meio-termo com base nas opções individuais. Além disso, os indivíduos podem ter algum tipo de relação com os outros que influenciam suas decisões. O modelo proposto aborda todas as etapas da missão de agradar ao público. Deve inferir quais são as preferências, calcular a recompensa das cenas para todos os indivíduos, estimar as escolhas de forma independente e em grupo, e permitir sistemas de Storytelling Interativos encontrar a história que maximiza a recompensa esperada da audiência. O modelo proposto pode ser facilmente estendido a outras áreas que envolvem usuários interagindo com ambientes digitais. / [en] To tell a story, the storyteller uses all his/her skills to entertain an audience. This task not only relies on the act of telling a story, but also on the ability to understand reactions of the audience during the telling of the story. It is not so difficult to adapt a story for a single individual based on his/her preferences and previous choices. However, the task of choosing what is best for a group becomes quite complicated. The selection by majority voting cannot be effective because it can discard alternatives that are secondary for some individuals, but that would work better for the group in question. Thus, the careless selection of events in a story could cause audience splitting, causing some people to give up keep watching because they were not pleased. This thesis proposes a new methodology to create tailored stories for an audience based on personality traits and preferences of each individual. As an audience may be composed of individuals with similar or mixed preferences, it is necessary to consider a middle ground solution based on the individual options. In addition, individuals may have some kind of relationship with others who influence their decisions. The proposed model addresses all steps in the quest to please the audience. It infers what the preferences are, computes the scenes reward for all individuals, estimates their choices independently and in group, and allows Interactive Storytelling systems to find the story that maximizes the expected audience reward. The proposed model can easily be extended to other areas that involve users interacting with digital environments.

L’objectif de cette thèse est de fournir un modèle, une méthode et un outil d’aide à la réalisation de scénarios interactifs. Cette solution répond au problème de l’opposition entre la maîtrise du déroulement d’un jeu vidéo et son niveau d’interactivité. En d’autres termes, notre but est d’aider à réaliser des jeux vidéo dont l’évolution satisfait les intentions des auteurs tout en autorisant un déroulement influencé par les choix du joueur (exprimés aux travers de ses actions). Pour cela, notre proposition permet à l’utilisateur de produire un modèle de scénario de jeu de bonne qualité qui est : (a) riche – le scénario fournit suffisamment d’options pertinentes aux personnages joueur/non-joueur de sorte que le joueur puisse déterminer le déroulement du jeu et sente toujours que le discours créé est intéressant, (b) valide – tous les discours possibles dans le scénario sont cohérents et répondent aux effets désirés par les auteurs, (c) opérationnel – la représentation du scénario est exécutable. Ce scénario est ensuite employé comme l’entrée d’un système de pilotage de narration interactive assurant le contrôle de la gestion du déroulement du jeu. Par conséquent, l’évolution des jeux, qui sont dirigés par un tel système de pilotage, garantit que l’exécution du jeu respecte les souhaits des auteurs, et en même temps, autorise la liberté des actions du joueur. Pour répondre au problème exposé ci-dessus, nous appuyons notre solution sur un modèle mathématique calculable (la logique linéaire) qui offre des mécanismes de déductions rigoureux et automatiques.Nous avons fait un tour d'horizon des approches existantes concernant le pilotage de narration interactive et la validation de scénario. Ceci nous permet d'identifier les principes nécessaires à notre solution, tels que les éléments d'architecture d'un système de pilotage ; la construction,la représentation, l'exécution de scénarios narratifs ; les propriétés de narration importantes ; l'évolution de référence des paramètres dramatiques ; la structuration de discours ; la stratégie pour la validation d'un scénario ; les informations qualitatives et statistiques nécessaires… Nos contributions portent (1) sur la définition d'un ensemble de propriétés de narration spécifiant la qualité des scénarios de jeu ; (2) sur la proposition de modèles, algorithmes et outils pour écrire des modèles de scénario respectant ces propriétés. Nous validons nos résultats par la réalisation de deux exemples. Le premier est un extrait d'un jeu éducatif expliquant comment appliquer notre outil en vue de produire un modèle de scénario de jeu valide, qui est exprimé par un séquent de logique linéaire dont la représentation est conforme à un métamodèle du calcul des séquents. Pour le second exemple, nous décrivons le processus de production complet d'un jeu vidéo réel basé sur l'histoire « Le Petit Chaperon rouge », mettant en oeuvre un prototype de système de pilotage que nous avons proposé, ce qui permet de dérouler le jeu selon le scénario valide produit, donc son évolution satisfait les intentions des auteurs, et en même temps, dépend des actions du joueur. / The objective of this PhD thesis is to provide a model, a method and a tool for producing interactive scenarios. Our solution solves the opposition between the controlle devolution of a video game and its interactivity level. In other words, our goal is to assist (authors) in producing video games whose unfolding satisfies authors’ intentions while it is simultaneously influenced by player’s choices (expressed via her/his actions).To this purpose, our proposal is to allow users to produce a good quality game scenario model, which is: (a) rich – the scenario provides enough pertinent options for player/non-player characters so that the player can determine the evolution of the game and always feels that the created discourse is interesting, (b) valid – all the possible discourses in the scenario are consistent and meet authors required effects, (c) operational – the representation of the scenario is executable. This scenario is then used as the input of an interactive storytelling control system to assist it in managing the unfolding of the game. As a consequence, the evolution of the video games, which are directed by such a control system, guarantees authors requirements, while at the same time, it depends on player’s actions. In order to execute the foregoing proposal, we base our solution on a calculable mathematical model (linear logic) which provides rigorous and automatic deduction mechanisms. We have made an overview of existing approaches concerning interactive storytelling controland scenario validation problems. This allows us to identify necessary principles for our solution, such as: architecture elements of a control system; construction, representation, implementation of narrative scenarios; important narrative properties; reference evolution of the drama parameters; discourse structuralization; scenario validation strategy; necessary statistical and qualitative information; etc. Our contributions consist (1) in the definition of a set of narrative properties specifying the quality of game scenarios; (2) in the proposal of models, algorithms and tools in order to produce scenario models respecting these properties. We validate our results by realizing two examples. The first is an extract of an education algame explaining how to apply our tools to produce a valid game scenario model, which is expressed by a linear logic sequent whose representation conforms to a metamodel of the sequent calculus. For the second example, we describe the complete production process of areal video game based on the story "Little Red Cap", implementing a prototype of control system we have proposed, which allows unfolding the game according to the produced valid scenario, so its evolution satisfies authors intentions and simultaneously depends on player's actions.

Creative Project Abstract: The creative project of this thesis is a script prototype for Underland, a crime drama video game and digital playable story that demonstrates writing and design methods for negotiating narrative and player agency. The story is set in October 2006 and players are investigative psychologists given access to a secure police server and tasked with analysing evidence related to two linked murders that have resulted in the arrest of journalist Silvi Moore. The aim is to uncover what happened and why by analysing Silvi’s flat, calendar of events, emails, texts, photos, voicemail, call log, 999 call, a map of the city of Plymouth and a crime scene. It is a combination of story exploration game and digital epistolary fiction that is structured via an authored fabula and dynamic syuzhet and uses the Internal-Exploratory and Internal-Ontological interactive modes to negotiate narrative and player agency. Its use of this structure and these modes shows how playable stories are uniquely positioned to deliver self-directed and empathetic emotional immersion simultaneously. The story is told in a mixture of enacted, embedded, evoked, environmental and epistolary narrative, the combination of which contributes new knowledge on how writers can use mystery, suspense and dramatic irony in playable stories. The interactive script prototype is accessible at underlandgame.com and is a means to represent how the final game is intended to be experienced by players. Thesis Abstract: This thesis considers writing and design methods for playable stories that negotiate narrative and player agency. By approaching the topic through the lens of creative writing practice, it seeks to fill a gap in the literature related to the execution of interactive and narrative devices as a practitioner. Chapter 1 defines the key terms for understanding the field and surveys the academic and theoretical debate to identify the challenges and opportunities for writers and creators. In this it departs from the dominant vision of the future of digital playable stories as the ‘holodeck,’ a simulated reality players can enter and manipulate and that shapes around them as story protagonists. Building on narratological theory it contributes a new term—the dynamic syuzhet—to express an alternate negotiation of narrative and player agency within current technological realities. Three further terms—the authored fabula, fixed syuzhet and improvised fabula—are also contributed as means to compare and contrast the narrative structures and affordances available to writers of live, digital and live-digital hybrid work. Chapter 2 conducts a qualitative analysis of digital, live and live-digital playable stories, released 2010–2016, and combines this with insights gained from primary interviews with their writers and creators to identify the techniques at work and their implications for narrative and player agency. This analysis contributes new knowledge to writing and design approaches in four interactive modes—Internal-Ontological, Internal-Exploratory, External-Ontological and External-Exploratory—that impact on where players are positioned in the work and how the experiential narrative unfolds. Chapter 3 shows how the knowledge developed through academic research informed the creation of a new playable story, Underland; as well as how the creative practice informed the academic research. Underland provides a means to demonstrate how making players protagonists of the experience, rather than of the story, enables the coupling of self-directed and empathetic emotional immersion in a way uniquely available to digital playable stories. It further shows how this negotiation of narrative and player agency can use a combination of enacted, embedded, evoked, environmental and epistolary narrative to employ dramatic irony in a new way. These findings demonstrate ways playable stories can be written and designed to deliver the ‘traditional’ pleasure of narrative and the ‘newer’ pleasure of player agency without sacrificing either.