5,825 research outputs found

    A survey of real-time crowd rendering

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    In this survey we review, classify and compare existing approaches for real-time crowd rendering. We first overview character animation techniques, as they are highly tied to crowd rendering performance, and then we analyze the state of the art in crowd rendering. We discuss different representations for level-of-detail (LoD) rendering of animated characters, including polygon-based, point-based, and image-based techniques, and review different criteria for runtime LoD selection. Besides LoD approaches, we review classic acceleration schemes, such as frustum culling and occlusion culling, and describe how they can be adapted to handle crowds of animated characters. We also discuss specific acceleration techniques for crowd rendering, such as primitive pseudo-instancing, palette skinning, and dynamic key-pose caching, which benefit from current graphics hardware. We also address other factors affecting performance and realism of crowds such as lighting, shadowing, clothing and variability. Finally we provide an exhaustive comparison of the most relevant approaches in the field.Peer ReviewedPostprint (author's final draft

    3D performance capture for facial animation

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    This work describes how a photogrammetry based 3D capture system can be used as an input device for animation. The 3D Dynamic Capture System is used to capture the motion of a human face, which is extracted from a sequence of 3D models captured at TV frame rate. Initially the positions of a set of landmarks on the face are extracted. These landmarks are then used to provide motion data in two different ways. First, a high level description of the movements is extracted, and these can be used as input to a procedural animation package (i.e. CreaToon). Second the landmarks can be used as registration points for a conformation process where the model to be animated is modified to match the captured model. This approach gives a new sequence of models, which have the structure of the drawn model but the movement of the captured sequence

    Functional requirements document for the Earth Observing System Data and Information System (EOSDIS) Scientific Computing Facilities (SCF) of the NASA/MSFC Earth Science and Applications Division, 1992

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    Five scientists at MSFC/ESAD have EOS SCF investigator status. Each SCF has unique tasks which require the establishment of a computing facility dedicated to accomplishing those tasks. A SCF Working Group was established at ESAD with the charter of defining the computing requirements of the individual SCFs and recommending options for meeting these requirements. The primary goal of the working group was to determine which computing needs can be satisfied using either shared resources or separate but compatible resources, and which needs require unique individual resources. The requirements investigated included CPU-intensive vector and scalar processing, visualization, data storage, connectivity, and I/O peripherals. A review of computer industry directions and a market survey of computing hardware provided information regarding important industry standards and candidate computing platforms. It was determined that the total SCF computing requirements might be most effectively met using a hierarchy consisting of shared and individual resources. This hierarchy is composed of five major system types: (1) a supercomputer class vector processor; (2) a high-end scalar multiprocessor workstation; (3) a file server; (4) a few medium- to high-end visualization workstations; and (5) several low- to medium-range personal graphics workstations. Specific recommendations for meeting the needs of each of these types are presented

    Facial Expression Recognition

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    Volume visualization of time-varying data using parallel, multiresolution and adaptive-resolution techniques

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    This paper presents a parallel rendering approach that allows high-quality visualization of large time-varying volume datasets. Multiresolution and adaptive-resolution techniques are also incorporated to improve the efficiency of the rendering. Three basic steps are needed to implement this kind of an application. First we divide the task through decomposition of data. This decomposition can be either temporal or spatial or a mix of both. After data has been divided, each of the data portions is rendered by a separate processor to create sub-images or frames. Finally these sub-images or frames are assembled together into a final image or animation. After developing this application, several experiments were performed to show that this approach indeed saves time when a reasonable number of processors are used. Also, we conclude that the optimal number of processors is dependent on the size of the dataset used

    Semi-automatic generation of three-dimensional visual algorithm simulations

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    Algorithms and data structures constitute the theoretical foundations of computer science and are an integral part of any classical computer science curriculum. Due to their high level of abstraction, the understanding of algorithms is of crucial concern to the vast majority of novice students. To facilitate the understanding and teaching of algorithms, a new research field termed "algorithm visualisation" evolved in the early 1980's. This field is concerned with innovating techniques and concepts for the development of effective algorithm visualisations for teaching, study, and research purposes. Due to the large number of requirements that high-quality algorithm visualisations need to meet, developing and deploying effective algorithm visualisations from scratch is often deemed to be an arduous, time-consuming task, which necessitates high-level skills in didactics, design, programming and evaluation. A substantial part of this thesis is devoted to the problems and solutions related to the automation of three-dimensional visual simulation of algorithms. The scientific contribution of the research presented in this work lies in addressing three concerns: - Identifying and investigating the issues related to the full automation of visual simulations. - Developing an automation-based approach to minimising the effort required for creating effective visual simulations. - Designing and implementing a rich environment for the visualisation of arbitrary algorithms and data structures in 3D. The presented research in this thesis is of considerable interest to (1) researchers anxious to facilitate the development process of algorithm visualisations, (2) educators concerned with adopting algorithm visualisations as a teaching aid and (3) students interested in developing their own algorithm animations.Als fundamentale abstrakte Konzepte der theoretischen Informatik sind Algorithmen und Datenstrukturen ein integraler Bestandteil jedes klassischen Kurrikulums eines Informatik-Studiums. Aufgrund ihrer abstrakten Eigenschaften stellt das Verstehen der Arbeitsweise von Algorithmen für viele Studierende eine große Herausforderung dar. Um das Lernen, Lehren und Erforschen von Algorithmen und Datenstrukturen zu vereinfachen, wurde Anfang der 80er Jahre ein Forschungsgebiet namens Algorithmenvisualisierung geschaffen. Als Teildisziplin der Softwarevisualisierung befasst sich dieses Forschungsfeld mit der dynamischen Visualisierung des abstrakten Verhaltens von Algorithmen und den diesen zugrundeliegenden Datenstrukturen. Algorithmenvisualisierung gilt als ein modernes e-Learning- und e-Teaching-Instrument, das Computergraphiktechniken einsetzt, um das Verstehen, Vermitteln und Erforschen von Algorithmen zu erleichtern. Ein Hauptziel dieser Dissertation besteht darin, Ansätze zur Automatisierung von dreidimensionalen visuellen Algorithmensimulationen zu entwickeln und zu implementieren. Eine visuelle Simulation eines Algorithmus ist eine interaktive Animation seines Verhaltens und der Zustandsänderungen seiner Daten, der eine Echtzeitsimulation des Algorithmus zugrunde liegt. Der wissenschaftliche Beitrag dieser Arbeit besteht darin, die bislang unerforschten Probleme der vollautomatischen Visualisierung von Algorithmen zu identifizieren und zu analysieren, mögliche Lösungswege und -ansätze zu entwickeln und diese in eine zu schaffende Algorithmenvisualisierungsumgebung zu implementieren. Desweiteren präsentiert die Arbeit einen Ansatz zur Minimierung des Aufwands für die Entwicklung von visuellen Simulationen paralleler Algorithmen und einen Ansatz zur passiven Animation von Algorithmen zu NP-vollständigen Problemen. ..

    Collision detection: review of methods and recent advances in crowd simulation

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    Crowd simulation is a large complex system that visualizes the behavior of crowd entities' movement and their interactions with the virtual environment. Crowd model is usually integrated into a virtual environment to make the environment alive. In the context of agent-based simulation (as in crowd simulation), it encompasses collision checking between moving agents that are present in the same environment. Hence, it is important to design an efficient and yet effective collision detection in crowd simulation. This is to ensure that it is cost effective toward computational processing usage and still produce a believable behavior. This paper presents a study of collision detection techniques in crowd models, and recent advancement to accelerate the process so that in turn, these efforts could also improve the performance and outcome of crowd model in virtual environment applications
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