Parallel Mesh Processing

Die aktuelle Forschung im Bereich der Computergrafik versucht den zunehmenden Ansprüchen der Anwender gerecht zu werden und erzeugt immer realistischer wirkende Bilder. Dementsprechend werden die Szenen und Verfahren, die zur Darstellung der Bilder genutzt werden, immer komplexer. So eine Entwicklung ist unweigerlich mit der Steigerung der erforderlichen Rechenleistung verbunden, da die Modelle, aus denen eine Szene besteht, aus Milliarden von Polygonen bestehen können und in Echtzeit dargestellt werden müssen. Die realistische Bilddarstellung ruht auf drei Säulen: Modelle, Materialien und Beleuchtung. Heutzutage gibt es einige Verfahren für effiziente und realistische Approximation der globalen Beleuchtung. Genauso existieren Algorithmen zur Erstellung von realistischen Materialien. Es gibt zwar auch Verfahren für das Rendering von Modellen in Echtzeit, diese funktionieren aber meist nur für Szenen mittlerer Komplexität und scheitern bei sehr komplexen Szenen. Die Modelle bilden die Grundlage einer Szene; deren Optimierung hat unmittelbare Auswirkungen auf die Effizienz der Verfahren zur Materialdarstellung und Beleuchtung, so dass erst eine optimierte Modellrepräsentation eine Echtzeitdarstellung ermöglicht. Viele der in der Computergrafik verwendeten Modelle werden mit Hilfe der Dreiecksnetze repräsentiert. Das darin enthaltende Datenvolumen ist enorm, um letztlich den Detailreichtum der jeweiligen Objekte darstellen bzw. den wachsenden Realitätsanspruch bewältigen zu können. Das Rendern von komplexen, aus Millionen von Dreiecken bestehenden Modellen stellt selbst für moderne Grafikkarten eine große Herausforderung dar. Daher ist es insbesondere für die Echtzeitsimulationen notwendig, effiziente Algorithmen zu entwickeln. Solche Algorithmen sollten einerseits Visibility Culling1, Level-of-Detail, (LOD), Out-of-Core Speicherverwaltung und Kompression unterstützen. Anderseits sollte diese Optimierung sehr effizient arbeiten, um das Rendering nicht noch zusätzlich zu behindern. Dies erfordert die Entwicklung paralleler Verfahren, die in der Lage sind, die enorme Datenflut effizient zu verarbeiten. Der Kernbeitrag dieser Arbeit sind neuartige Algorithmen und Datenstrukturen, die speziell für eine effiziente parallele Datenverarbeitung entwickelt wurden und in der Lage sind sehr komplexe Modelle und Szenen in Echtzeit darzustellen, sowie zu modellieren. Diese Algorithmen arbeiten in zwei Phasen: Zunächst wird in einer Offline-Phase die Datenstruktur erzeugt und für parallele Verarbeitung optimiert. Die optimierte Datenstruktur wird dann in der zweiten Phase für das Echtzeitrendering verwendet. Ein weiterer Beitrag dieser Arbeit ist ein Algorithmus, welcher in der Lage ist, einen sehr realistisch wirkenden Planeten prozedural zu generieren und in Echtzeit zu rendern

Improving Usability in Procedural Modeling

This work presents new approaches and algorithms for procedural modeling geared towards user convenience and improving usability, in order to increase artists’ productivity. Procedural models create geometry for 3D models from sets of rules. Existing approaches that allow to model trees, buildings, and terrain are reviewed and possible improvements are discussed. A new visual programming language for procedural modeling is discussed, where the user connects operators to visual programs called model graphs. These operators create geometry with textures, assign or evaluate variables or control the sequence of operations. When the user moves control points using the mouse in 3D space, the model graph is executed to change the geometry interactively. Thus, model graphs combine the creativity of freehand modeling with the power of programmed modeling while displaying the program structure more clearly than textbased approaches. Usability is increased as a result of these advantages. Also, an interactive editor for botanical trees is demonstrated. In contrast to previous tree modeling systems, we propose linking rules, parameters and geometry to semantic entities. This has the advantage that problems of associating parameters and instances are completely avoided. When an entity is clicked in the viewport, its parameters are displayed immediately, changes are applied to selected entities, and viewport editing operations are reflected in the parameter set. Furthermore, we store the entities in a hierarchical data structure and allow the user to activate recursive traversal via selection options for all editing operations. The user may choose to apply viewport or parameter changes to a single entity or many entities at once, and only the geometry for the affected entities needs to be updated. The proposed user interface simplifies the modeling process and increases productivity. Interactive editing approaches for 3D models often allow more precise control over a model than a global set of parameters that is used to generate a shape. However, usually scripted procedural modeling generates shapes directly from a fixed set of parameters, and interactive editing mostly uses a fixed set of tools. We propose to use scripts not only to generate models, but also for manipulating the models. A base script would set up the state of an object, and tool scripts would modify that state. The base script and the tool scripts generate geometry when necessary. Together, such a collection of scripts forms a template, and templates can be created for various types of objects. We examine how templates simplify the procedural modeling workflow by allowing for editing operations that are context-sensitive, flexible and powerful at the same time. Many algorithms have been published that produce geometry for fictional landscapes. There are algorithms which produce terrain with minimal setup time, allowing to adapt the level of detail as the user zooms into the landscape. However, these approaches lack plausible river networks, and algorithms that create eroded terrain with river networks require a user to supervise creation and minutes or hours of computation. In contrast to that, this work demonstrates an algorithm that creates terrain with plausible river networks and adaptive level of detail with no more than a few seconds of preprocessing. While the system can be configured using parameters, this text focuses on the algorithm that produces the rivers. However, integrating more tools for user-controlled editing of terrain would be possible.Verbesserung der Usability bei prozeduraler Modellierung Ziel der vorliegenden Arbeit ist es, prozedurale Modellierung durch neue neue Ansätze und Algorithmen einfacher, bequemer und anwendungsfreundlicher zu machen, und damit die Produktivität der Künstler zu erhöhen. Diese Anforderungen werden häufig unter dem Stichwort Usability zusammengefasst. Prozedurale Modelle spezifizieren 3D-Modelle über Regeln. Existierende Ansätze für Bäume, Gebäude und Terrain werden untersucht und es werden mögliche Verbesserungen diskutiert. Eine neue visuelle Programmiersprache für prozedurale Modelle wird vorgestellt, bei der Operatoren zu Modellgraphen verschaltet werden. Die Operatoren erzeugen texturierte Geometrie, weisen Variablen zu und werten sie aus, oder sie steuern den Ablauf der Operationen. Wenn der Benutzer Kontrollpunkte im Viewport mit der Maus verschiebt, wird der Modellgraph ausgeführt, um interaktiv neue Geometrie für das Modell zu erzeugen. Modellgraphen kombinieren die kreativen Möglichkeiten des freihändigen Editierens mit der Mächtigkeit der prozeduralen Modellierung. Darüber hinaus sind Modellgraphen eine visuelle Programmiersprache und stellen die Struktur der Algorithmen deutlicher dar als textbasierte Programmiersprachen. Als Resultat dieser Verbesserungen erhöht sich die Usability. Ein interaktiver Editor für botanische Bäume wird ebenfalls vorgestellt. Im Gegensatz zu früheren Ansätzen schlagen wir vor, Regeln, Parameter und Geometrie zu semantischen Entitäten zu verschmelzen. Auf diese Weise werden Zuordnungsprobleme zwischen Parametern und deren Instanzen komplett vermieden. Wenn im Viewport eine Instanz angeklickt wird, werden sofort ihre Parameter angezeigt, alle Änderungen wirken sich direkt auf die betroffenen Instanzen aus, und Änderungen im Viewport werden sofort in den Parametern reflektiert. Darüber hinaus werden die Entitäten in einer hierarchischen Datenstruktur gespeichert und alle Änderungen können rekursiv auf der Hierarchie ausgeführt werden. Dem Benutzer werden Selektionsoptionen zur Verfügung gestellt, über die er Änderungen an den Parametern oder Änderungen im Viewport an einzelnen oder vielen Instanzen gleichzeitig vornehmen kann. Anschließend muss das System nur die Geometrie der betroffenen Instanzen aktualisieren. Auch hier ist das Ziel, das User Interface möglichst an den Bedürfnissen des Benutzers auszurichten, um Vereinfachungen und eine Erhöhung der Produktivität zu erreichen. Interaktive Editieransätze für 3D-Modelle erlauben häufig eine präzisere Kontrolle über ein Modell als ein globaler Parametersatz, der für die Erzeugung des Modells genutzt wird. Trotzdem erzeugen prozedurale Modellierskripte ihre Modelle meist direkt aus einem festen Parametersatz, während interaktive Tools meist mit hartkodierten Operationen arbeiten. Wir schlagen vor, Skripte nicht nur zur Erzeugung der Modelle zu verwenden, sondern auch um die erzeugten Modelle zu editieren. Ein Basisskript soll die Statusinformationen eines Objekts anlegen, während weitere Skripte diesen Status verändern und passende Geometrie erzeugen. Diese Skripte bilden dann ein Template zum Erzeugen einer Klasse von Objekten. Verschiedene Objekttypen können jeweils ihr eigenes Template haben. Wir zeigen, wie Templates den Workflow mit prozeduralen Modellen vereinfachen können, indem Operationen geschaffen werden, die gleichzeitig kontext-sensitiv, mächtig und flexibel sind. Es existiert eine Reihe von Verfahren, um Geometrie für synthetische Landschaften zu erzeugen. Ein Teil der Algorithmen erzeugt Geometrie mit minimaler Vorberechnung und erlaubt es, den Detailgrad der Landschaft interaktiv an die Perspektive anzupassen. Leider fehlen den so erzeugten Landschaften plausible Flussnetze. Algorithmen, die erodiertes Terrain mit Flussnetzen erzeugen, müssen aufwendig vom Benutzer überwacht werden und brauchen Minuten oder Stunden Rechenzeit. Im Gegensatz dazu stellen wir einen Algorithmus vor, der plausible Flussnetze erzeugt, während sich der Betrachter interaktiv durch die Szene bewegt. Das System kann über Parameter gesteuert werden, aber der Fokus liegt auf dem Algorithmus zur Erzeugung der Flüsse. Dennoch wäre es möglich, Tools zum benutzergesteuerten Editieren von Terrain zu integrieren

Terrain Diffusion Network: Climatic-Aware Terrain Generation with Geological Sketch Guidance

Sketch-based terrain generation seeks to create realistic landscapes for virtual environments in various applications such as computer games, animation and virtual reality. Recently, deep learning based terrain generation has emerged, notably the ones based on generative adversarial networks (GAN). However, these methods often struggle to fulfill the requirements of flexible user control and maintain generative diversity for realistic terrain. Therefore, we propose a novel diffusion-based method, namely terrain diffusion network (TDN), which actively incorporates user guidance for enhanced controllability, taking into account terrain features like rivers, ridges, basins, and peaks. Instead of adhering to a conventional monolithic denoising process, which often compromises the fidelity of terrain details or the alignment with user control, a multi-level denoising scheme is proposed to generate more realistic terrains by taking into account fine-grained details, particularly those related to climatic patterns influenced by erosion and tectonic activities. Specifically, three terrain synthesisers are designed for structural, intermediate, and fine-grained level denoising purposes, which allow each synthesiser concentrate on a distinct terrain aspect. Moreover, to maximise the efficiency of our TDN, we further introduce terrain and sketch latent spaces for the synthesizers with pre-trained terrain autoencoders. Comprehensive experiments on a new dataset constructed from NASA Topology Images clearly demonstrate the effectiveness of our proposed method, achieving the state-of-the-art performance. Our code and dataset will be publicly available

Virtual player design using self-learning via competitive coevolutionary algorithms

The Google Artificial Intelligence (AI) Challenge is an international contest the objective of which is to program the AI in a two-player real time strategy (RTS) game. This AI is an autonomous computer program that governs the actions that one of the two players executes during the game according to the state of play. The entries are evaluated via a competition mechanism consisting of two-player rounds where each entry is tested against others. This paper describes the use of competitive coevolutionary (CC) algorithms for the automatic generation of winning game strategies in Planet Wars, the RTS game associated with the 2010 contest. Three different versions of a prime algorithm have been tested. Their common nexus is not only the use of a Hall-of-Fame (HoF) to keep note of the winners of past coevolutions but also the employment of an archive of experienced players, termed the hall-of-celebrities (HoC), that puts pressure on the optimization process and guides the search to increase the strength of the solutions; their differences come from the periodical updating of the HoF on the basis of quality and diversity metrics. The goal is to optimize the AI by means of a self-learning process guided by coevolutionary search and competitive evaluation. An empirical study on the performance of a number of variants of the proposed algorithms is described and a statistical analysis of the results is conducted. In addition to the attainment of competitive bots we also conclude that the incorporation of the HoC inside the primary algorithm helps to reduce the effects of cycling caused by the use of HoF in CC algorithms.This work is partially supported by Spanish MICINN under Project ANYSELF (TIN2011-28627-C04-01),3 by Junta de Andalucía under Project P10-TIC-6083 (DNEMESIS) and by Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech

Design Patterns : Implementation in video game programming

The goal of this thesis was to develop Last Planets, a social mobile game for iOS devices. The game development theory and the design patterns are portrayed in the first part of this study. The second part presents how such theories are put into practice during the development of Last Planets. The completion of the project resulted in the launch of Last Planets during spring 2016. Multiple design patterns were chosen to be implemented within the code base. Patterns such as Observer, Strategy and Model-View-Controller create the foundation architecture and convention for the code base. Meanwhile, various other support systems are implemented with the help of Singleton and Decorator pattern. However, the implementation process did not occur instantaneously nor at the beginning of the project but was rather a gradual realizing and refactoring effort. Applying these design patterns has helped ease up maintenance work as well as improved the readability of the source code. Additionally, these design patterns have also enabled several major functionalities of both client and server sides. However, in a few cases of overusing design patterns, the game source code has actually become more complex and tangled. Since the materials of this thesis are limited, readers are highly recommended to study design patterns further. Careful consideration before applying design pattern is also vital for project success. Insightful decisions can both maximize the values of design patterns as well as avoiding the risk of abusing them

Increasing the performance and realism of procedurally generated buildings

As multimedia such as games and movies grow, so does the need for content. Textures, 3D models, expansive terrain, sound effects, and other data must be generated to support and enrich these multimedia productions. As this need for content continues to grow, two critical problems emerge: the cost of hiring artists to create the content becomes extremely large, as does the amount of memory needed to store and manipulate the content.;To combat these issues, procedural content generation, or content generated algorithmically rather than via an artist, has been introduced. Algorithmically generating content allows for rapid creation of large amounts of certain classes of content with little human effort; further, this content can be represented extremely compactly, often by only exposing a handful of parameters.;In the realm of 3D building generation, split grammars have proven useful for generating a wide variety of buildings while being relatively intuitive. These split grammars have been used to generate entire cities full of detailed buildings with a fairly small number of rules.;Split grammars have two important areas which can be expanded upon: first, the writing of an appropriate grammar can require a significant amount of work and knowledge, especially when a grammar is required that must follow a certain building style while providing a high degree of variation. Second, applying these grammars to produce a building can be slow, often requiring an offline pregeneration phase which eliminates the usefulness the size benefits of the grammar\u27s compactness.;For the first problem, we propose a data mining approach to refining preexisting grammars, wherein a user can specify buildings which they prefer, and from these preferences a set of rules will be generated that will guide future building generation. We will show that the generated rules have a high degree of accuracy when used to predict whether a user will like or dislike a building, often in the upper 90%.;For the second problem, we provide two areas of improvement: a preprocessing step which parses a split grammar to make it easier and more efficient to apply the grammar without loss of generality, and a scheme that allows the execution of a grammar entirely within a geometry shader on a modern graphics processing unit (GPU) such that building generation can take advantage of the parallelization found on modern graphics cards. We will show that this second improvement can provide a speed benefit anywhere between 3 and 10 times a purely CPU approach, with further speed benefits possible depending on the nature of the grammars

Agency in the Internet of Things

This report summarises and extends the work done for the task force on IoT terminated in 2012. In response to DG CNECT request, the JRC studied this emergent technology following the methodologies pertaining to the Science and Technology Studies field. The aim of this document is therefore to present and to explore, on the basis of present day conceptions of relevant values, rights and norms, some of the “ethical issues” arising from the research, development and deployment of IoT, focusing on agency, autonomy and social justice. We start by exploring the types of imaginaries that seem to be entrenched and inspiring the developments of IoT and how they become portrayed in “normal” communication from corporations and promoters to the ordinary citizen (chapter 2). We report the empirical work we have conducted, namely the JRC contribution to the limited public debate initiated by the European Commission via the Your Voice portal during the Spring of 2012 (chapter 3) and an empirical exercise involving participants of two IoT conferences (chapter 4). This latter exercise sought to illustrate how our notions of goodness, trust, relationships, agency and autonomy are negotiated through the appropriation of unnoticed ordinary objects; this contributes to the discussion about ethical issues at stake with the emerging IoT vision beyond the right to privacy, data protection and security. Furthermore, based on literature review the report reflects on two of the main ethical issues that arise with the IoT vision: agency (and autonomy) and social justice (chapter 5), examining eventually governance alternatives of the challenged ethical issues (chapter 6).JRC.G.7-Digital Citizen Securit

Archaeology of Digital Environments: Tools, Methods, and Approaches

Digital archaeologists use digital tools for conducting archaeological work, but their potential also lies in applying archaeological thinking and methods to understanding digital built environments (i.e., software) as contemporary examples of human settlement, use, and abandonment. This thesis argues for digital spaces as archaeological artifacts, sites, and landscapes that can be investigated in both traditional and non-traditional ways. At the core of my research is the fundamental argument that human-occupied digital spaces can be studied archaeologically with existing and modified theory, tools, and methods to reveal that human occupation and use of synthetic worlds is similar to how people behave in the natural world. Working digitally adds new avenues of investigation into human behavior in relation to the things people make, modify, and inhabit. In order to investigate this argument, the thesis focuses on three video game case studies, each using different kinds of archaeology specifically chosen to help understand the software environments being researched: 1) epigraphy, stylometry, and text analysis for the code-artifact of Colossal Cave Adventure; 2) photogrammetry, 3D printing, GIS mapping, phenomenology, and landscape archaeology within the designed, digital heritage virtual reality game-site of Skyrim VR; 3) actual survey and excavation of 30 heritage sites for a community of displaced human players in the synthetic landscape of No Man’s Sky. My conclusions include a blended approach to conducting future archaeological fieldwork in digital built environments, one that modifies traditional approaches to archaeological sites and material in a post/transhuman landscape. As humanity continues trending towards constant digital engagement, archaeologists need to be prepared to study how digital places are settled, used, and abandoned. This thesis takes a step in that direction using the vernacular of games as a starting point