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Item Fast Continuous Collision Detection among Deformable Models using Graphics Processors(The Eurographics Association, 2006) Govindaraju, Naga K.; Kabul, Ilknur; Lin, Ming C.; Manocha, Dinesh; Ming Lin and Roger HubboldWe present an interactive algorithm to perform continuous collision detection between general deformable models using graphics processors (GPUs). We model the motion of each object in the environment as a continuous path and check for collisions along the paths. Our algorithm precomputes the chromatic decomposition for each object and uses visibility queries on GPUs to quickly compute potentially colliding sets of primitives. We introduce a primitive classification technique to perform efficient continuous self-collision. We have implemented our algorithm on a 3:0 GHz Pentium IV PC with a NVIDIA 7800 GPU, and we highlight its performance on complex simulations composed of several thousands of triangles. In practice, our algorithm is able to detect all contacts, including self-collisions, at image-space precision in tens of milli-seconds.Item Partial Shape Matching Using Transformation Parameter Similarity(Copyright © 2015 The Eurographics Association and John Wiley & Sons Ltd., 2015) Guerrero, Paul; Auzinger, Thomas; Wimmer, Michael; Jeschke, Stefan; Deussen, Oliver and Zhang, Hao (Richard)In this paper, we present a method for non‐rigid, partial shape matching in vector graphics. Given a user‐specified query region in a 2D shape, similar regions are found, even if they are non‐linearly distorted. Furthermore, a non‐linear mapping is established between the query regions and these matches, which allows the automatic transfer of editing operations such as texturing. This is achieved by a two‐step approach. First, pointwise correspondences between the query region and the whole shape are established. The transformation parameters of these correspondences are registered in an appropriate transformation space. For transformations between similar regions, these parameters form surfaces in transformation space, which are extracted in the second step of our method. The extracted regions may be related to the query region by a non‐rigid transform, enabling non‐rigid shape matching.In this paper, we present a method for non‐rigid, partial shape matching in vector graphics. Given a user‐specified query region in a 2D shape, similar regions are found, even if they are non‐linearly distorted. Furthermore, a non‐linear mapping is established between the query regions and these matches, which allows the automatic transfer of editing operations such as texturing. This is achieved by a two‐step approach. First, pointwise correspondences between the query region and the whole shape are established. The transformation parameters of these correspondences are registered in an appropriate transformation space. For transformations between similar regions, these parameters form surfaces in transformation space, which are extracted in the second step of our method. The extracted regions may be related to the query region by a non‐rigid transform, enabling non‐rigid shape matching.Item Progressive Hulls for Intersection Applications(Blackwell Publishers, Inc and the Eurographics Association, 2003) Platis, Nikos; Theoharis, TheoharisProgressive meshes are an established tool for triangle mesh simplification. By suitably adapting the simplification process, progressive hulls can be generated which enclose the original mesh in gradually simpler, nested meshes. We couple progressive hulls with a selective refinement framework and use them in applications involving intersection queries on the mesh. We demonstrate that selectively refinable progressive hulls considerably speed up intersection queries by efficiently locating intersection points on the mesh. Concerning the progressive hull construction, we propose a new formula for assigning edge collapse priorities that significantly accelerates the simplification process, and enhance the existing algorithm with several conditions aimed at producing higher quality hulls. Using progressive hulls has the added advantage that they can be used instead of the enclosed object when a lower resolution of display can be tolerated, thus speeding up the rendering process.ACM CSS: I.3.3 Computer Graphics-Picture/Image Generation, I.3.5 Computer Graphics-Computational Geometry and Object Modeling, I.3.7 Computer Graphics-Three-Dimensional Graphics and RealismItem Simulation of Facial Muscle Actions Based on Rational Free Form Deformations(Blackwell Science Ltd and the Eurographics Association, 1992) Kalra, Prem; Mangili, Angelo; Thalmann, Nadia Magnenat; Thalmann, DanielThis paper describes interactive facilities for simulating abstract muscle actions using Rational Free Form Deformations (RFFD). The particular muscle action is simulated as the displacement of the control points of the control-unit for an RFFD defined on a region of interest. One or several simulated muscle actions constitute a Minimum Perceptible Action (MPA), which is defined as the atomic action unit, similar to Action Unit (AU) of the Facial Action Coding System (FACS), to build an expression.Item Interactive Rendering of Volumetric Data Sets(The Eurographics Association, 1994) Juskiw, "Scott; Durdle, Nelson G.; W. StrasserThe bela architecture for interactive rendering of regularly structured volumetric data sets is presented. The proposed architecture is scalable and uses custom processors to achieve high-speed shading, projection. and composition of voxel primitives. A general purpose image composition network supports the accumulation of both volumetric and geometric elements into the final rendered scene. Data access contentions between processors are eliminated via the use of an enhanced dual object space and image space partitioning scheme that does not require replication or redistribution of rendered data. The bela architecture is intended for rendering large data sets and meets the performance requirements of a full frame interactive image generation system.Item Constellation Models for Sketch Recognition(The Eurographics Association, 2006) Sharon, Dana; Panne, Michiel van de; Thomas Stahovich and Mario Costa SousaSketch-based modeling shares many of the difficulties of the branch of computer vision that deals with single image interpretation. Most obviously, they must both identify the parts observed in a given 2D drawing or image.We draw on constellation models first proposed in the computer vision literature to develop probabilistic models for object sketches, based on multiple example drawings. These models are then applied to estimate the most-likely labels for a new sketch. A multi-pass branch-and-bound algorithm allows well-formed sketches to be quickly labelled, while still supporting the recognition of more ambiguous sketches. Results are presented for five classes of objects.Item Haptics-based Modelling of Pigmented Skin Lesions(The Eurographics Association, 2015) Granados, Alejandro; Bryan, James; Abdalla, Taha; Osborne, Genevieve; Bello, Fernando; Katja Bühler and Lars Linsen and Nigel W. JohnDermatology is under-represented in medical undergraduate education with newly graduated doctors not being able to identify common and important skin conditions. In order to become competent in diagnosing skin lesions, it is important to encounter multiple examples of a condition, as they vary between individuals. Three popular lesions have been identified due to their importance, including nodular melanoma, seborrhoeic keratosis and cherry haemangioma. In this paper we propose a haptics-enabled learning tool for pigmented skin lesions based on haptic texturing. Geometrical modelling, skin deformation and haptics modelling are described. Results of the implementation are presented along with an initial validation study comparing the haptics-based simulator with other methods, including temporary tattoos and silicon made models.Item The Impulse Graph: A New Dynamic Structure For Global Collisions(Blackwell Publishers Ltd and the Eurographics Association, 2000) Baciu, George; Keung Wong, SaiIn interactive virtual environments and dynamic simulations, collisions between complex objects and articulated bodies may occur simultaneously at multiple points or regions of interference. Many solutions to the collision response problem are formulated based on the local pair-wise contact dynamics. In this article, we present a new solution to the global interactions and dynamic response between multiple structures in a three-dimensional environment. This is based on a new dynamic impulse graph that tracks the reaction forces through the entire system and gives a global view of all the interactions in a multibody system.Item Dynamic Load Balancing within a High PerformanceGraphics System(The Eurographics Association, 1991) Selzer, Harald; A. KaufmanInteractive 3D graphics applications require significant arithmetic processing to meet the ever-inreasing desire for higher image complexity and higher resolution in displayed images. This paper describes a graphics processor architecture with a high degree of parallelismconnected to a distributed frame buffer. The architecture can be configured with an arbitrary number of identical, high level programmable processors operating in parallel.Within the architecture an automatic load balancing mechanism is presented whichdistributes the processing load between geometry and rendering section. After the unique features of the architecture are described the load balancing mechanismis analyzed and the increase of performance is demonstrated."Item intsys96(1996)