Symposium on Point Based Graphics 06
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A Dynamic Surface Reconstruction Framework for Large Unstructured Point Sets
Allègre, Rémi
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Chaine, Raphaëlle
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Akkouche, Samir
Template Deformation for Point Cloud Fitting
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Stoll, Carsten
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Karni, Zachi
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Rössl, Christian
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Yamauchi, Hitoshi
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Seidel, Hans-Peter
Single-Pass Point Rendering and Transparent Shading
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Zhang, Yanci
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Pajarola, Renato
Splat/Mesh Blending, Perspective Rasterization and Transparency for Point-Based Rendering
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Guennebaud, Gaël
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Barthe, Loïc
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Paulin, Mathias
GPU-Based Ray-Casting of Quadratic Surfaces
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Sigg, Christian
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Weyrich, Tim
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Botsch, Mario
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Gross, Markus
Interactive Out-Of-Core Texturing with Point-Sampled Textures
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Boubekeur, Tamy
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Schlick, Christophe
Approximating Geodesics on Point Set Surfaces
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Ruggeri, Mauro R.
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Darom, Tal
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Saupe, Dietmar
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Kiryati, Nahum
A Fast k-Neighborhood Algorithm for Large Point-Clouds
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Sankaranarayanan, Jagan
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Samet, Hanan
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Varshney, Amitabh
Perceptually Guided Rendering of Textured Point-based Models
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Qu, Lijun
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Yuan, Xiaoru
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Nguyen, Minh X.
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Meyer, Gary W.
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Chen, Baoquan
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Windsheimer, Jered E.
Octree-Based Progressive Geometry Coding of Point Clouds
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Huang, Yan
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Peng, Jingliang
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Kuo, C.-C. Jay
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Gopi, M.
Efficient and Prioritized Point Subsampling for CSRBF Compression
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Kitago, Masaki
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Gopi, M.
Instant Points: Fast Rendering of Unprocessed Point Clouds
Wimmer, Michael
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Scheiblauer, Claus
Versatile Virtual Materials Using Implicit Connectivity
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Wicke, Martin
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Hatt, Philipp
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Pauly, Mark
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Müller, Matthias
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Gross, Markus
Integrating Mesh and Meshfree Methods for Physics-Based Fracture and Debris Cloud Simulation
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Zhang, Nan
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Zhou, Xiangmin
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Sha, Desong
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Yuan, Xiaoru
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Tamma, Kumar
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Chen, Baoquan
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Recent Submissions
Item Laser Scanner Super-resolution(The Eurographics Association, 2006) Kil, Yong Joo; Mederos, Boris; Amenta, Nina; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe give a method for improving the resolution of surfaces captured with a laser range scanner by combining many very similar scans. This idea is an application of the 2D image processing technique known as superresolution. The input lower-resolution scans are each randomly shifted, so that each one contributes slightly different information to the final model. Noise is reduced by averaging the input scans.Item A Dynamic Surface Reconstruction Framework for Large Unstructured Point Sets(The Eurographics Association, 2006) Allègre, Rémi; Chaine, Raphaëlle; Akkouche, Samir; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe present a method to reconstruct simplified mesh surfaces from large unstructured point sets, extending recent work on dynamic surface reconstruction. The method consists of two core components: an efficient selective reconstruction algorithm, based on geometric convection, that simplifies the input point set while reconstructing a surface, and a local update algorithm that dynamically refines or coarsens the reconstructed surface according to specific local sampling constraints. We introduce a new data-structure that significantly accelerates the original selective reconstruction algorithm and makes it possible to handle point set models with millions of sample points. Our data-structure mixes a kd-tree with the Delaunay triangulation of the selected points enriched with a sparse subset of landmark sample points. This design efficiently responds to the specific spatial location issues of the geometric convection algorithm. We also develop an out-of-core implementation of the method, that permits to seamlessly reconstruct and interactively update simplified mesh surfaces from point sets that do not fit into main memory.Item Template Deformation for Point Cloud Fitting(The Eurographics Association, 2006) Stoll, Carsten; Karni, Zachi; Rössl, Christian; Yamauchi, Hitoshi; Seidel, Hans-Peter; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerThe reconstruction of high-quality surface meshes from measured data is a vital stage in digital shape processing. We present a new approach to this problem that deforms a template surface to fit a given point cloud. Our method takes a template mesh and a point cloud as input, the latter typically shows missing parts and measurement noise. The deformation process is initially guided by user specified correspondences between template and data, then during iterative fitting new correspondences are established. This approach is based on a Laplacian setting for the template without need of any additional meshing of the data or cross-parameterization. The reconstructed surface fits to the point cloud while it inherits shape properties and topology of the template. We demonstrate the effectiveness of the approach for several point data sets from different sources.Item Single-Pass Point Rendering and Transparent Shading(The Eurographics Association, 2006) Zhang, Yanci; Pajarola, Renato; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerHardware accelerated point-based rendering (PBR) algorithms have suffered in the past from multiple rendering passes; possibly a performance limiting factor. Two passes over the point geometry have been necessary because a first visibility-splatting pass has been necessary for conservative e-z-buffer visibility culling in the following point-interpolation rendering pass. This separation into visibility-splatting and point-blending, hence processing the point geometry twice, is a fundamental drawback of current GPU-based PBR algorithms. In this paper we introduce a new framework for GPU accelerated PBR algorithm whose basic idea is deferred blending. In contrast to prior algorithms, we formulate the smooth point interpolation problem as an image compositing post-processing task. This is achieved by separating the input point data in a pre-process into not self-overlapping minimal independent groups of points. As an extension of this concept, we can for the first time render transparent point surfaces as well on the GPU. For simple transparency effects, our novel algorithm only needs a single geometry rendering pass. For high-quality transparent image synthesis an extra rendering pass is sufficient. Furthermore, per-fragment reflective and refractive multilayer effects are supported in our algorithm.Item Splat/Mesh Blending, Perspective Rasterization and Transparency for Point-Based Rendering(The Eurographics Association, 2006) Guennebaud, Gaël; Barthe, Loïc; Paulin, Mathias; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerIn this paper we present multiple simple and efficient improvements for splatting based rendering systems. In a first step we derive a perspectively correct splat rasterization algorithm suitable for both efficient implementation on current GPU and the design of fast dedicated rasterization units taking advantages of incremental calculations. Next, we propose a new efficient and high-quality approximation of the optimal EWA (Elliptical Weighted Average) filtering framework. We also show how transparent point-clouds can be rendered by current GPU in an order independent way by using a modified depth-peeling approach. Finally, in the context of hybrid points and polygons rendering systems, we present a simple mechanism to smooth the transitions between the different representations. Combined to previous contributions in the field, these improvements lead to a high-quality, performant and fullfeatured hardware-oriented splatting rendering system.Item GPU-Based Ray-Casting of Quadratic Surfaces(The Eurographics Association, 2006) Sigg, Christian; Weyrich, Tim; Botsch, Mario; Gross, Markus; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerQuadratic surfaces are frequently used primitives in geometric modeling and scientific visualization, such as rendering of tensor fields, particles, and molecular structures. While high visual quality can be achieved using sophisticated ray tracing techniques, interactive applications typically use either coarsely tessellated polygonal approximations or pre-rendered depth sprites, thereby trading off visual quality and perspective correctness for higher rendering performance. In contrast, we propose an efficient rendering technique for quadric primitives based on GPU-accelerated splatting. While providing similar performance as point-sprites, our methods provides perspective correctness and superior visual quality using per-pixel ray-casting.Item Interactive Out-Of-Core Texturing with Point-Sampled Textures(The Eurographics Association, 2006) Boubekeur, Tamy; Schlick, Christophe; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerThe visualization of huge 3D objects becomes available on common workstations thanks to highly optimized data-structures and out-of-core frameworks for rendering. However, the editing, and in particular, the texturing of such objects is still a challenging task, since usual methods for optimized rendering are not easily amenable to interactive modification. In this paper, we introduce the idea of point-sampled textures, and show how to interactively texture such a huge model at various scales, without any parameterization. An adaptive in-core point-based approximated geometry is first created by employing an efficient out-of-core point-sampling algorithm. This simplified geometry is then used for an interactive and multi-scale point-based texturing. Finally, a feature-preserving kernel is used to convert the point-based model into a global 3D texture which can be applied back on the initial huge geometry. Our technique thus provides a flexible tool to generate, edit and apply size-independent textures to a wide range of huge 3D objects thanks to point-based methods.Item Approximating Geodesics on Point Set Surfaces(The Eurographics Association, 2006) Ruggeri, Mauro R.; Darom, Tal; Saupe, Dietmar; Kiryati, Nahum; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe present a technique for computing piecewise linear approximations of geodesics on point set surfaces by minimizing an energy function defined for piecewise linear path. The function considers path length, closeness to the surface for the nodes of the piecewise linear path and for the intermediate line segments. Our method is robust with respect to noise and outliers. In order to avoid local minima, a good initial piecewise linear approximation of a geodesic is provided by Dijkstra s algorithm that is applied to a proximity graph constructed over the point set. As the proximity graph we use a sphere-of-influence weighted graph extended for surfel sets. The convergence of our method has been studied and compared to results of other methods by running experiments on surfaces whose geodesics can be computed analytically. Our method is presented and optimized for surfel-based representations but it has been implemented also for MLS surfaces. Moreover, it can also be applied to other surface representations, e.g., triangle meshes, radial-basis functions, etc.Item A Fast k-Neighborhood Algorithm for Large Point-Clouds(The Eurographics Association, 2006) Sankaranarayanan, Jagan; Samet, Hanan; Varshney, Amitabh; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerAlgorithms that use point-cloud models make heavy use of the neighborhoods of the points. These neighborhoods are used to compute the surface normals for each point, mollification, and noise removal. All of these primitive operations require the seemingly repetitive process of finding the k nearest neighbors of each point. These algorithms are primarily designed to run in main memory. However, rapid advances in scanning technologies have made available point-cloud models that are too large to fit in the main memory of a computer. This calls for more efficient methods of computing the k nearest neighbors of a large collection of points many of which are already in close proximity. A fast k nearest neighbor algorithm is presented that makes use of the locality of successive points whose k nearest neighbors are sought to significantly reduce the time needed to compute the neighborhood needed for the primitive operation as well as enable it to operate in an environment where the data is on disk. Results of experiments demonstrate an order of magnitude improvement in the time to perform the algorithm and several orders of magnitude improvement in work efficiency when compared with several prominent existing method.Item Perceptually Guided Rendering of Textured Point-based Models(The Eurographics Association, 2006) Qu, Lijun; Yuan, Xiaoru; Nguyen, Minh X.; Meyer, Gary W.; Chen, Baoquan; Windsheimer, Jered E.; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerIn this paper, we present a textured point-based rendering scheme that takes into account the masking properties of the human visual system. In our system high quality textures are mapped to point-based models. Given one texture, an importance map is first computed using the visual masking tool included in the JPEG2000 standard. This importance map indicates the masking potential of the texture. During runtime, point-based models are simplified and rendered based on this computed importance. In our point simplification method, called Simplification by Random Numbers (SRN), each point in the model is pre-assigned a random value. During rendering, the preassigned value is compared with the preferred local point density (derived from importance) to determine whether this point will be rendered. Our method can achieve coherent simplification for point models.Item Octree-Based Progressive Geometry Coding of Point Clouds(The Eurographics Association, 2006) Huang, Yan; Peng, Jingliang; Kuo, C.-C. Jay; Gopi, M.; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe propose a generic point cloud encoder that compresses geometry data including positions and normals of point samples corresponding to 3D objects with arbitrary topology. In this work, the coding process is led by an iterative octree cell subdivision of the object space. At each level of subdivision, positions of point samples are approximated by the geometry centers of all tree-front cells while normals are approximated by their statistical average within each of the tree-front cells. With this framework, we employ attribute-dependent encoding techniques to exploit different characteristics of various attributes. As a result, significant improvement in the rate-distortion (R-D) performance has been obtained with respect to the prior art. Furthermore, the proposed point cloud encoder can be potentially used for lossless geometry coding of 3D point clouds, given sufficient levels of octree expansion and normal space partitioning.Item Octree-based Point-Cloud Compression(The Eurographics Association, 2006) Schnabel, Ruwen; Klein, Reinhard; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerIn this paper we present a progressive compression method for point sampled models that is specifically apt at dealing with densely sampled surface geometry. The compression is lossless and therefore is also suitable for storing the unfiltered, raw scan data. Our method is based on an octree decomposition of space. The point-cloud is encoded in terms of occupied octree-cells. To compress the octree we employ novel prediction techniques that were specifically designed for point sampled geometry and are based on local surface approximations to achieve high compression rates that outperform previous progressive coders for point-sampled geometry. Moreover we demonstrate that additional point attributes, such as color, which are of great importance for point-sampled geometry, can be well integrated and efficiently encoded in this framework.Item Efficient and Prioritized Point Subsampling for CSRBF Compression(The Eurographics Association, 2006) Kitago, Masaki; Gopi, M.; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe present a novel cost function to prioritize points and subsample a point set based on the dominant geometric features and local sampling density of the model. This cost function is easy to compute and at the same time provides rich feedback in the form of redundancy and non-uniformity in the sampling. We use this cost function to simplify the given point set and thus reduce the CSRBF (Compactly Supported Radial Basis Function) coefficients of the surface fit over this point set. Further compression of CSRBF data set is effected by employing lossy encoding techniques on the geometry of the simplified model, namely the positions and normal vectors, and lossless encoding on the CSRBF coefficients. Results on the quality of subsampling and our compression algorithms are provided. The major advantages of our method include highly efficient subsampling using carefully designed, effective, and easy compute cost function, in addition to a very high PSNR (Peak Signal to Noise Ratio) of our compression technique relative to other known point set subsampling techniques.Item Instant Points: Fast Rendering of Unprocessed Point Clouds(The Eurographics Association, 2006) Wimmer, Michael; Scheiblauer, Claus; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe present an algorithm to display enormous unprocessed point clouds at interactive rates without requiring long postprocessing. The novelty here is that we do not make any assumptions about sampling density or availability of normal vectors for the points. This is very important because such information is available only after lengthy postprocessing of scanned datasets, whereas users want to interact with the dataset immediately. Instant Points is an out-of-core algorithm that makes use of nested octrees and an enhanced version of sequential point trees.Item Versatile Virtual Materials Using Implicit Connectivity(The Eurographics Association, 2006) Wicke, Martin; Hatt, Philipp; Pauly, Mark; Müller, Matthias; Gross, Markus; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe propose a new method for strain computation in mesh-free simulations. Without storing connectivity information, we compute strain using local rest states that are implicitly defined by the current system configuration. Particles in the simulation are subject to restoring forces arranging them in a locally defined lattice. The orientation of the lattice is found using local shape matching techniques. The strain state of each particle can then be computed by comparing the actual positions of the neighboring particles to their assigned lattice positions. All necessary information needed to compute strains is contained in the current state of the simulation, no rest state or connectivity information is stored. Since no time integration is used to compute the strain state, errors cannot accumulate, and the method is well-suited for stiff materials. In order to simulate phase transitions, the strain computation can be integrated into an existing particle-based fluid simulation framework. Implementing phase transitions between liquid and solid states becomes simple and elegant, since no transfer of material between different representations is needed. Using the current neighborhood relationships, the model provides penalty-based inter-object and self-collision handling at no additional computational cost.Item Integrating Mesh and Meshfree Methods for Physics-Based Fracture and Debris Cloud Simulation(The Eurographics Association, 2006) Zhang, Nan; Zhou, Xiangmin; Sha, Desong; Yuan, Xiaoru; Tamma, Kumar; Chen, Baoquan; Mario Botsch and Baoquan Chen and Mark Pauly and Matthias ZwickerWe present a hybrid framework for physics-based simulation of fracture and debris clouds. Previous methods mainly consider bulk fractures. However, in many situations, small fractured pieces and debris are visually important. Our framework takes a hybrid approach that integrates both tetrahedron-based finite element and particlebased meshfree methods. The simulation starts with a tetrahedral mesh. When the damage of elements reaches a damage failure threshold, the associated nodes are converted into mass-based particles. Molecular dynamics is used to model particle motion and interaction with other particles and the remaining elements. In rendering, we propose an algorithm of dynamically extracting a polygonal boundary surface for the damaged elements and particles. Our framework is simple, accurate, and efficient. It avoids the remeshing and stability problems of pure mesh-based techniques and pure meshfree methods and offers high visual realism.