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Now showing 1 - 6 of 6
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    Multi-Domain Real-time Planning in Dynamic Environments
    (ACM SIGGRAPH / Eurographics Association, 2013) Kapadia, Mubbasir; Beacco, Alejandro; Garcia, Francisco; Reddy, Vivek; Pelechano, Nuria; Badler, Norman I.; Theodore Kim and Robert Sumner
    This paper presents a real-time planning framework for multicharacter navigation that enables the use of multiple heterogeneous problem domains of differing complexities for navigation in large, complex, dynamic virtual environments. The original navigation problem is decomposed into a set of smaller problems that are distributed across planning tasks working in these different domains. An anytime dynamic planner is used to efficiently compute and repair plans for each of these tasks, while using plans in one domain to focus and accelerate searches in more complex domains. We demonstrate the benefits of our framework by solving many challenging multi-agent scenarios in complex dynamic environments requiring space-time precision and explicit coordination between interacting agents, by accounting for dynamic information at all stages of the decision-making process.
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    Recreating Early Islamic Glass Lamp Lighting
    (The Eurographics Association, 2009) Jr., Joseph T. Kider; Fletcher, Rebecca L.; Yu, Nancy; Holod, Renata; Chalmers, Alan; Badler, Norman I.; Kurt Debattista and Cinzia Perlingieri and Denis Pitzalis and Sandro Spina
    Early Islamic light sources are not simple, static, uniform points, and the fixtures themselves are often combinations of glass, water, fuel and flame. Various physically based renderers such as Radiance are widely used for modeling ancient architectural scenes; however they rarely capture the true ambiance of the environment due to subtle lighting effects. Specifically, these renderers often fail to correctly model complex caustics produced by glass fixtures, water level, and fuel sources.While the original fixtures of the 8th through 10th century Mosque of Cordoba in Spain have not survived, we have applied information gathered from earlier and contemporary sites and artifacts, including those from Byzantium, to assume that it was illuminated by either single jar lamps or supported by polycandela that cast unique downward caustic lighting patterns which helped individuals to navigate and to read. To re-synthesize such lighting, we gathered experimental archaeological data and investigated and validated how various water levels and glass fixture shapes, likely used during early Islamic times, changed the overall light patterns and downward caustics. In this paper, we propose a technique called Caustic Cones, a novel data-driven method to "shape" the light emanating from the lamps to better recreate the downward lighting without resorting to computationally expensive photon mapping renderers.Additionally, we demonstrate on a rendering of the Mosque of Cordoba how our approach greatly benefits archaeologists and architectural historians by providing a more authentic visual simulation of early Islamic glass lamp lighting.
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    Fruit Senescence and Decay Simulation
    (The Eurographics Association and Blackwell Publishing Ltd., 2011) Jr., Joseph T. Kider; Raja, Samantha; Badler, Norman I.; M. Chen and O. Deussen
    Aging and imperfections provide important visual cues for realism. We present a novel physically-based approach for simulating the biological aging and decay process in fruits. This method simulates interactions between multiple processes. Our biologically-derived, reaction-diffusion model generates growth patterns for areas of fungal and bacterial infection. Fungal colony spread and propagation is affected by both bacterial growth and nutrient depletion. This process changes the physical properties of the surface of the fruit as well as its internal volume substrate. The fruit is physically simulated with parameters such as skin thickness and porosity, water content, flesh rigidity, ambient temperature, humidity, and proximity to other surfaces. Our model produces a simulation that closely mirrors the progression of decay in real fruits under similar parameterized conditions. Additionally, we provide a tool that allows artists to customize the input of the program to produce generalized fruit simulations.
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    SPREAD : Sound Propagation and Perception for Autonomous Agents in Dynamic Environments
    (ACM SIGGRAPH / Eurographics Association, 2013) Huang, Pengfei; Kapadia, Mubbasir; Badler, Norman I.; Theodore Kim and Robert Sumner
    The perception of sensory information and its impact on behavior is a fundamental component of being human. While visual perception is considered for navigation, collision, and behavior selection, the acoustic domain is relatively unexplored. Recent work in acoustics focuses on synthesizing sound in 3D environments; however, the perception of acoustic signals by a virtual agent is a useful and realistic adjunct to any behavior selection mechanism. In this paper, we present SPREAD, a novel agent-based sound perception model using a discretized sound packet representation with acoustic features including amplitude, frequency range, and duration. SPREAD simulates how sound packets are propagated, attenuated, and degraded as they traverse the virtual environment. Agents perceive and classify the sounds based on the locally-received packet set using a hierarchical clustering scheme, and have individualized hearing and understanding of their surroundings. Using this model, we demonstrate several simulations that greatly enrich controls and outcomes.
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    THE COMPUTER GRAPHICS SCENE IN THE UNITED STATES
    (The Eurographics Association, 1984) Badler, Norman I.; Carlbom, Ingrid; K. BO and H.A. TUCKER
    We briefly survey the major thrusts of computer graphics activities, examining trends and topics rather than offering a comprehensive survey of all that is happening. The directions of professional activities, hardware, software, and algorithms are outlined. Within hardware we examine workstations, personal graphics systems, high performance systems, and low level VLSI chips; within software, standards and interactive system design; within algorithms, visible surface rendering and shading, three-dimensional modeling techniques, and animation.
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    STATE OF THE ART IN COMPUTER GRAPHICS: A SIGGRAPH PERSPECTIVE
    (The Eurographics Association, 1981) Badler, Norman I.; Ellis, Robert A.; J. L. Encarnacao