22 research outputs found

    A tool for generating three dimensional animation on computers

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    Ankara : The Department of Graphic Design and the Institute of Fine Arts of Bilkent Univ. , 1991.Thesis (Master's) -- Bilkent University, 1991.Includes bibliographical references leaves 31-32.In this work, a three dimensional computer animation system has been designed to be employed in schools, for the training of art students on basic three dimensional animation techniques. Puppet Theater, as we have called the system, utilizes the flexibility and effectiveness of the low-end hardware, namely IBM PC™ computers supported with Targa 16™ graphics board and gives special emphasis to user friendliness. It Is basically a software to design three dimensional objects and choreograph the object data in the computer's memory, before rendering the resulting scenery with shading methods. The system is the result of reflecting the recent advances in the field of computer graphics and pushing the potentials of the existing platform. Software is Implemented in C language, thus the code is transportable. A custom designed object oriented windowing system called WODNTW is used as the user Interface. This open windowing system supports pull-down menus, interactive buttons, scalable windows and other popular user interface elements.Türün, Cemil ŞinasiM.S

    Tangent-ball techniques for shape processing

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    Shape processing defines a set of theoretical and algorithmic tools for creating, measuring and modifying digital representations of shapes.  Such tools are of paramount importance to many disciplines of computer graphics, including modeling, animation, visualization, and image processing.  Many applications of shape processing can be found in the entertainment and medical industries. In an attempt to improve upon many previous shape processing techniques, the present thesis explores the theoretical and algorithmic aspects of a difference measure, which involves fitting a ball (disk in 2D and sphere in 3D) so that it has at least one tangential contact with each shape and the ball interior is disjoint from both shapes. We propose a set of ball-based operators and discuss their properties, implementations, and applications.  We divide the group of ball-based operations into unary and binary as follows: Unary operators include: * Identifying details (sharp, salient features, constrictions) * Smoothing shapes by removing such details, replacing them by fillets and roundings * Segmentation (recognition, abstract modelization via centerline and radius variation) of tubular structures Binary operators include: * Measuring the local discrepancy between two shapes * Computing the average of two shapes * Computing point-to-point correspondence between two shapes * Computing circular trajectories between corresponding points that meet both shapes at right angles * Using these trajectories to support smooth morphing (inbetweening) * Using a curve morph to construct surfaces that interpolate between contours on consecutive slices The technical contributions of this thesis focus on the implementation of these tangent-ball operators and their usefulness in applications of shape processing. We show specific applications in the areas of animation and computer-aided medical diagnosis.  These algorithms are simple to implement, mathematically elegant, and fast to execute.Ph.D.Committee Chair: Jarek Rossignac; Committee Member: Greg Slabaugh; Committee Member: Greg Turk; Committee Member: Karen Liu; Committee Member: Maryann Simmon

    Stylised procedural animation

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    This thesis develops a stylised procedural paradigm for computer graphics animation. Cartoon effects animations - stylised representations of natural phenomena - have presented a long-standing, difficult challenge to computer animators. We propose a framework for achieving the intricacy of effects motion with minimal animator intervention.Our approach is to construct cartoon effects by simulating the hand-drawing process through synthetic, computational means. We create a system which emulates the stylish appearance, movements of cartoon effects in both 2D and 3D environments. Our computational models achieve this by capturing the essential characteristics common to all cartoon effects: structure modelling, dynamic controlling and stylised rendering.To validate our framework, we have implemented a cartoon effects system for a range of effects including water effects, fire, smoke, rain and snow. Each effect model has its own static structure such as how the different parts are related temporarily. The flexibility of our approach is suggested most evidently by the high-level controls on shape, colour, timing and rendering on the effects. Like their hand-drawn counterparts, they move consistently while retaining the hand-crafted look.Since the movements of cartoon effects are animated procedurally, their detailed motions need not be keyframed. This thesis therefore demonstrates a powerful approach to computer animation in which the animator plays the role of a high level controller, rather than the more conventional hand-drawing slave. Our work not only achieves cartoon effects animation of un-precedented complexity, but it also provides an interesting experimental domain for related research disciplines toward more creative and expressive image synthesis in animation

    Hybrid modelling of time-variant heterogeneous objects.

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    The physical world consists of a wide range of objects of a diverse constitution. Past research was mainly focussed on the modelling of simple homogeneous objects of a uniform constitution. Such research resulted in the development of a number of advanced theoretical concepts and practical techniques for describing such physical objects. As a result, the process of modelling and animating certain types of homogeneous objects became feasible. In fact most physical objects are not homogeneous but heterogeneous in their constitution and it is thus important that one is able to deal with such heterogeneous objects that are composed of diverse materials and may have complex internal structures. Heterogeneous object modelling is still a very new and evolving research area, which is likely to prove useful in a wide range of application areas. Despite its great promise, heterogeneous object modelling is still at an embryonic state of development and there is a dearth of extant tools that would allow one to work with static and dynamic heterogeneous objects. In addition, the heterogeneous nature of the modelled objects makes it appealing to employ a combination of different representations resulting in the creation of hybrid models. In this thesis we present a new dynamic Implicit Complexes (IC) framework incorporating a number of existing representations and animation techniques. This framework can be used for the modelling of dynamic multidimensional heterogeneous objects. We then introduce an Implicit Complexes Application Programming Interface (IC API). This IC API is designed to provide various applications with a unified set of tools allowing these to model time-variant heterogeneous objects. We also present a new Function Representation (FRep) API, which is used for the integration of FReps into complex time-variant hybrid models. This approach allows us to create a practical multilevel modelling system suited for complex multidimensional hybrid modelling of dynamic heterogeneous objects. We demonstrate the advantages of our approach through the introduction of a novel set of tools tailored to problems encountered in simulation applications, computer animation and computer games. These new tools empower users and amplify their creativity by allowing them to overcome a large number of extant modelling and animation problems, which were previously considered difficult or even impossible to solve

    Interactive simulation of fire, burn and decomposition

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    This work presents an approach to effectively integrate into one unified modular fire simulation framework the major processes related to fire, namely: a burning process, chemical combustion, heat distribution, decomposition and deformation of burning solids, and rigid body simulation of the residue. Simulators for every stage are described, and the modular structure enables switching to different simulators if more accuracy or more interactivity is desired. A “Stable Fluids” based three gas system is used to model the combustion process, and the heat generated during the combustion is used to drive the flow of the hot air. Objects, if exposed to enough heat, ignite and start burning. The decomposition of the burning object is modeled as a level set method, driven by the pyrolysis process, where the burning object releases combustible gases. Secondary deformation effects, such as bending burning matches and crumpling burning paper, are modeled as a proxy based deformation. Physically based simulation, done at interactive rates, enables the user to ef- ficiently test different setups, as well as interact and change the conditions during the simulation. The graphics card is used to generate additional frames for real-time visualization. This work further proposes a method for controlling and directing high resolution simulations. An interactive coarse resolution simulation is provided to the user as a “preview” to control and achieve the desired simulation behavior. A higher resolution “final” simulation that creates all the fine scale behavior is matched to the preview simulation such that the preview and final simulations behave in a similar manner. In this dissertation, we highlighted a gap within the CG community for the simulation of fire. There has not previously been a physically based yet interactive simulation for fire. This dissertation describes a unified simulation framework for physically based simulation of fire and burning. Our results show that our implementation can model fire, objects catching fire, burning objects, decomposition of burning objects, and additional secondary deformations. The results are plausible even at interactive frame rates, and controllable

    Hybrid modelling of time-variant heterogeneous objects

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    The physical world consists of a wide range of objects of a diverse constitution. Past research was mainly focussed on the modelling of simple homogeneous objects of a uniform constitution. Such research resulted in the development of a number of advanced theoretical concepts and practical techniques for describing such physical objects. As a result, the process of modelling and animating certain types of homogeneous objects became feasible. In fact most physical objects are not homogeneous but heterogeneous in their constitution and it is thus important that one is able to deal with such heterogeneous objects that are composed of diverse materials and may have complex internal structures. Heterogeneous object modelling is still a very new and evolving research area, which is likely to prove useful in a wide range of application areas. Despite its great promise, heterogeneous object modelling is still at an embryonic state of development and there is a dearth of extant tools that would allow one to work with static and dynamic heterogeneous objects. In addition, the heterogeneous nature of the modelled objects makes it appealing to employ a combination of different representations resulting in the creation of hybrid models. In this thesis we present a new dynamic Implicit Complexes (IC) framework incorporating a number of existing representations and animation techniques. This framework can be used for the modelling of dynamic multidimensional heterogeneous objects. We then introduce an Implicit Complexes Application Programming Interface (IC API). This IC API is designed to provide various applications with a unified set of tools allowing these to model time-variant heterogeneous objects. We also present a new Function Representation (FRep) API, which is used for the integration of FReps into complex time-variant hybrid models. This approach allows us to create a practical multilevel modelling system suited for complex multidimensional hybrid modelling of dynamic heterogeneous objects. We demonstrate the advantages of our approach through the introduction of a novel set of tools tailored to problems encountered in simulation applications, computer animation and computer games. These new tools empower users and amplify their creativity by allowing them to overcome a large number of extant modelling and animation problems, which were previously considered difficult or even impossible to solve.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    On-Demand Collaboration in Programming

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    In programming, on-demand assistance occurs when developers seek support for their tasks as needed. Traditionally, this collaboration happens within teams and organizations in which people are familiar with the context of requests and tasks. More recently, this type of collaboration has become ubiquitous outside of teams and organizations, due to the success of paid online crowdsourcing marketplaces (e.g., Upwork) and free online question-answering websites (e.g., Stack Overflow). Thousands of requests are posted on these platforms on a daily basis, and many of them are not addressed in a timely manner for a variety of reasons, including requests that often lack sufficient context and access to relevant artifacts. In consequence, on-demand collaboration often results in suboptimal productivity and unsatisfactory user experiences. This dissertation includes three main parts: First, I explored the challenges developers face when requesting help from or providing assistance to others on demand. I have found seven common types of requests (e.g., seeking code examples) that developers use in various projects when an on-demand agent is available. Compared to studying existing supporting systems, I suggest eight key system features to enable more effective on-demand remote assistance for developers. Second, driven by these findings, I designed and developed two systems: 1) CodeOn, a system that enables more effective task hand-offs (e.g., rich context capturing) between end-user developers and remote helpers than exciting synchronous support systems by allowing asynchronous responses to on-demand requests; and 2) CoCapture, a system that enables interface designers to easily create and then accurately describe UI behavior mockups, including changes they want to propose or questions they want to ask about an aspect of the existing UI. Third, beyond software development assistance, I also studied intelligent assistance for embedded system development (e.g., Arduino) and revealed six challenges (e.g., communication setup remains tedious) that developers have during on-demand collaboration. Through an imaginary study, I propose four design implications to help develop future support systems with embedded system development. This thesis envisions a future in which developers in all kinds of domains can effortlessly make context-rich, on-demand requests at any stage of their development processes, and qualified agents (machine or human) can quickly be notified and orchestrate their efforts to promptly respond to the requests.PHDInformationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/166144/1/yanchenm_1.pd

    Animating the evolution of software

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    The use and development of open source software has increased significantly in the last decade. The high frequency of changes and releases across a distributed environment requires good project management tools in order to control the process adequately. However, even with these tools in place, the nature of the development and the fact that developers will often work on many other projects simultaneously, means that the developers are unlikely to have a clear picture of the current state of the project at any time. Furthermore, the poor documentation associated with many projects has a detrimental effect when encouraging new developers to contribute to the software. A typical version control repository contains a mine of information that is not always obvious and not easy to comprehend in its raw form. However, presenting this historical data in a suitable format by using software visualisation techniques allows the evolution of the software over a number of releases to be shown. This allows the changes that have been made to the software to be identified clearly, thus ensuring that the effect of those changes will also be emphasised. This then enables both managers and developers to gain a more detailed view of the current state of the project. The visualisation of evolving software introduces a number of new issues. This thesis investigates some of these issues in detail, and recommends a number of solutions in order to alleviate the problems that may otherwise arise. The solutions are then demonstrated in the definition of two new visualisations. These use historical data contained within version control repositories to show the evolution of the software at a number of levels of granularity. Additionally, animation is used as an integral part of both visualisations - not only to show the evolution by representing the progression of time, but also to highlight the changes that have occurred. Previously, the use of animation within software visualisation has been primarily restricted to small-scale, hand generated visualisations. However, this thesis shows the viability of using animation within software visualisation with automated visualisations on a large scale. In addition, evaluation of the visualisations has shown that they are suitable for showing the changes that have occurred in the software over a period of time, and subsequently how the software has evolved. These visualisations are therefore suitable for use by developers and managers involved with open source software. In addition, they also provide a basis for future research in evolutionary visualisations, software evolution and open source development

    Proof of Concept For the Use of Motion Capture Technology In Athletic Pedagogy

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    Visualization has long been an important method for conveying complex information. Where information transfer using written and spoken means might amount to 200-250 words per minute, visual media can often convey information at many times this rate. This makes visualization a potentially important tool for education. Athletic instruction, particularly, can involve communication about complex human movement that is not easily conveyed with written or spoken descriptions. Video based instruction can be problematic since video data can contain too much information, thereby making it more difficult for a student to absorb what is cognitively necessary. The lesson is to present the learner what is needed and not more. We present a novel use of motion capture animation as an educational tool for teaching athletic movements. The advantage of motion capture is its ability to accurately represent real human motion in a minimalist context which removes extraneous information normally found in video. Motion capture animation only displays motion information, not additional information regarding the motion context. Producing an “automated coach” would be too large and difficult a problem to solve within the scope of a Master's thesis but we can perform initial steps including producing a useful software tool which performs data analysis on two motion datasets. We believe such a tool would be beneficial to a human coach as an analysis tool and the work would provide some useful understanding of next important steps towards perhaps someday producing an automated coach

    Towards procedural music-driven animation: exploring audio-visual complementarity

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    Master dissertation (Master Degree in Computer Science)This thesis intends to describe our approach towards developing a framework for the interactive creation of music driven animations. We aim to create an integrated environment where real-time musical information is easily accessible and is able to be flexibly used for manipulating different aspects of a reactive simulation. Such modifications are specified through the use of a scripting language and include, for instance, geometrical transformations and geometry synthesis, gradual colour changes as well as the application of arbitrary forces. Our framework thus represents a proof-of-concept for converting musical information into arbitrary modifications to a dynamic simulation, producing a variety of animations. This is possible due to a bargaining between control and automation, where control is present by allowing the user to program these modifications with a scripting language and automation is present by using physics and interpolation to estimate the visual effects resulting from those modifications. The particular test case for our system was the animation/simulation of a growing tree reacting to wind. In order to control or influence both the tree growth and wind field, as well as other visual parameters, the system accepts two different but complementary representations of music: a MIDI event stream and raw audio data. Different musical features are obtainable from each of these representations. On one hand, by using MIDI, we are able to discretely synchronise visual effects with the basic elements of music, such as the sounding of notes or chords. On the other, using audio, we are able to produce continuous changes by obtaining numerical data from basic spectral analysis. Our framework provides a common interface for the combined application of these different sources of musical information to the generation of visual imagery, under the form of procedural animations. We will describe algorithms presented in multiple research papers, namely for tree generation, wind field generation and tree reaction to wind, briefly detailing our implementation and architecture. We also describe why each of these particular methods was chosen, how they are organised in our platform and how their parameters may be modified from our scripting environment leading to what we regard as the procedural generation of animations. By allowing the user to access musical information and give them control of what we have come to refer to as animation primitives, such as wind and tree growth, we believe to have taken a first step towards exploring a novel concept with a seemingly endless expressive potential.Esta dissertação descreve o desenvolvimento de uma plataforma para a criação interativa de animações dirigidas por música. Focamo-nos em desenvolver um ambiente integrado onde vários aspetos de uma animação podem ser controlados pelo processamento em tempo real de informação musical, com recurso a uma linguagem de script. O caso de teste específico da nossa aplicação consiste na animação de uma árvore em crescimento capaz de reagir a um campo de vento dinâmico. De forma a controlar ou influenciar quer o crescimento da árvore, quer o campo de vento, o sistema aceita como input duas representações diferentes, mas complementares, de música, uma sequência contínua de eventos MIDI e áudio. Realçamos a distinção entre estas duas representações visto que apesar de serem ambas referentes a música, são fundamentalmente diferentes em termos da informação que contêm. Eventos MIDI contêm informação simbólica relativa à interpretação da música, nomeadamente os tempos de começo e final de notas. Por outro lado, informação áudio consiste num sinal contínuo, que resulta da gravação de um instrumento ou de uma atuação musical. Com MIDI, a nossa plataforma é capaz de sincronizar alterações discretas à simulação, com base nos elementos fundamentais da teoria musical, como o soar de notas ou acordes. Com informação áudio, é possível produzir alterações contínuas com base nos dados numéricos obtidos por análise espectral elementar do sinal de áudio. Neste documento serão descritos vários algoritmos apresentados em artigos de investigação, nomeadamente para a geração de árvores, geração de campos de vento e reação da árvore ao vento. Iremos descrever os motivos que levaram à sua escolha, a sua organização na nossa plataforma e os vários parâmetros que podemos modificar a partir do nosso ambiente de scripting. Em suma, a nossa plataforma pode ser descrita como um sistema que converte informação musical em alterações arbitrárias a um ambiente, que por sua vez influencia uma simulação reativa, produzindo animações. Foi estabelecido um compromisso entre controlo e automação de forma a tornar esta abordagem possível. O controlo provém da capacidade de programar as modificações que ocorrem no sistema, sendo que é utilizada automação de forma a estimar o movimento resultante de tais modificações. Ao fornecer ao utilizador informação musical em tempo real e oferecer-lhe controlo sobre o que nos referimos como "primitivas de animação", como o controlo sobre vento e o crescimento da árvore, consideramos que demos um primeiro passo no que toca à exploração de um novo conceito, com um potencial expressivo aparentemente infinito
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