Symposium on Point Based Graphics 07
Permanent URI for this collection
Sampling Point-Set Implicits
[meta data] [files:
Proenca, Joao
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Jorge, Joaquim A.
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Sousa, Mario C.
Low-Discrepancy Point Sampling of Meshes for Rendering
[meta data] [files:
Quinn, Jonathan A.
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Langbein, Frank C.
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Martin, Ralph R.
Direct Computing of Surface Curvatures for Point-Set Surfaces
[meta data] [files:
Yang, Pinghai
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Qian, Xiaoping
Interactive Editing of Large Point Clouds
Wand, Michael
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Berner, Alexander
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Bokeloh, Martin
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Fleck, Arno
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Hoffmann, Mark
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Jenke, Philipp
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Maier, Benjamin
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Staneker, Dirk
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Schilling, Andreas
SIMOD: Making Freeform Deformation Size-Insensitive
[meta data] [files:
Boubekeur, Tamy
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Sorkine, Olga
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Schlick, Christophe
Efficient Refinement of Dynamic Point Data
[meta data] [files:
Solenthaler, Barbara
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Zhang, Yanci
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Pajarola, Renato
Efficient Bounds for Point-Based Animations
[meta data] [files:
Steinemann, Denis
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Otaduy, Miguel A.
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Gross, Markus
Efficient Point-Based Rendering Using Image Reconstruction
[meta data] [files:
Marroquim, Ricardo
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Kraus, Martin
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Cavalcanti, Paulo Roma
Topological Methods for the Analysis of High Dimensional Data Sets and 3D Object Recognition
[meta data] [files:
Singh, Gurjeet
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Memoli, Facundo
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Carlsson, Gunnar
Surfel-Based Billboard Hierarchies for Fast Rendering of 3D-Objects
[meta data] [files:
Holst, Mathias
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Schumann, Heidrun
A Parallelly Decodeable Compression Scheme for Efficient Point-Cloud Rendering
[meta data] [files:
Schnabel, Ruwen
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Moeser, Sebastian
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Klein, Reinhard
Self-Similarity-Based Compression of Point Clouds, with Application to Ray Tracing
[meta data] [files:
Hubo, Erik
;
Mertens, Tom
;
Haber, Tom
;
Bekaert, Philippe
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Item Sampling Point-Set Implicits(The Eurographics Association, 2007) Proenca, Joao; Jorge, Joaquim A.; Sousa, Mario C.; M. Botsch and R. Pajarola and B. Chen and M. ZwickerWe present a novel approach for point-set implicit surface sampling that is able to rapidly distribute particles over the surface of 3D objects. Our methods benefit from the inner structure of a MPU implicit to obtain a near-optimal initial distribution, with higher densities in areas of higher complexity. The adequate number of particles to effectively sample the surface is determined almost automatically and in accordance to the surface characteristics. We also use the MPU information to obtain local surface complexity heuristics that are used in the simulation stage of the particle system. Shape modeling operations are directly supported and the redistribution of particles is very fast for local edits. We present performance results that show that our system is faster than other state-of-the art approaches for the same number of points.Item Low-Discrepancy Point Sampling of Meshes for Rendering(The Eurographics Association, 2007) Quinn, Jonathan A.; Langbein, Frank C.; Martin, Ralph R.; M. Botsch and R. Pajarola and B. Chen and M. ZwickerA novel point sampling framework for polygonal meshes is presented, based on sampling a mesh according to a density-controlled low-discrepancy distribution. The local sampling density can be controlled by a density func- tional defined by the user, e.g. to preserve local features, or to achieve desired data reduction rates. To sample the mesh, it is cut into a disc topology, and a parametrisation is generated. The parameterised mesh is sampled using a Hilbert curve in the parameter domain, which is adapted to parametric distortions and mapped onto the mesh. 1D sample points along the Hilbert curve are then generated, correcting for parametric distortion and a user- specified local density, to give a density-controlled low-discrepancy sampling of the mesh. After a pre-processing step, the sampling density can be adjusted in real-time. Experiments show that this approach can quickly resample existing meshes with low discrepancy samples. The effectiveness and speed of the approach are demonstrated by applying it to viewpoint dependent rendering, level of detail representation, and interactive remeshing.Item Direct Computing of Surface Curvatures for Point-Set Surfaces(The Eurographics Association, 2007) Yang, Pinghai; Qian, Xiaoping; M. Botsch and R. Pajarola and B. Chen and M. ZwickerAccurate computing of the curvatures of a surface from its discrete form is of fundamental importance for many graphics and engineering applications. The moving least-squares (MLS) surface from Levin [Lev2003] and its variants have been successfully used to define point-set surfaces in a variety of point cloud data based modeling and rendering applications. This paper presents a set of analytical equations for direct computing of surface curvatures from pointset surfaces based on the explicit definition from [AK04a, AK04b]. Besides the Gaussian parameter involved in the MLS definition, these analytical equations allow us to conduct direct and exact differential geometric analysis on the point-set surfaces without specifying any subjective parameters. Our experimental validation on both synthetic and real point cloud data demonstrates that such direct computing from analytical equations provides a viable approach for surface curvature evaluation for unorganized point cloud data.Item Interactive Editing of Large Point Clouds(The Eurographics Association, 2007) Wand, Michael; Berner, Alexander; Bokeloh, Martin; Fleck, Arno; Hoffmann, Mark; Jenke, Philipp; Maier, Benjamin; Staneker, Dirk; Schilling, Andreas; M. Botsch and R. Pajarola and B. Chen and M. ZwickerThis paper describes a new out-of-core multi-resolution data structure for real-time visualization and interactive editing of large point clouds. In addition, an editing system is discussed that makes use of the novel data structure to provide interactive editing tools for large scanner data sets. The new data structure provides efficient rendering and allows for handling very large data sets using out-of-core storage. Unlike related previous approaches, it also provides dynamic operations for online insertion, deletion and modification of points with time mostly independent of scene complexity. This permits local editing of huge models in real time while maintaining a full multi-resolution representation for visualization. The data structure is used to implement a prototypical editing system for large point clouds. It provides real-time local editing tools for huge data sets as well as a two-resolution scripting mode for planning large, non-local changes which are subsequently performed in an externally efficient offline computation. We evaluate our implementation on several synthetic and real-world examples of sizes up to 63GB.Item SIMOD: Making Freeform Deformation Size-Insensitive(The Eurographics Association, 2007) Boubekeur, Tamy; Sorkine, Olga; Schlick, Christophe; M. Botsch and R. Pajarola and B. Chen and M. ZwickerFreeform deformation techniques are powerful and flexible tools for interactive 3D shape editing. However, while interactivity is the key constraint for the usability of such tools, it cannot be maintained when the complexity of either the 3D model or the applied deformation exceeds a given workstation-dependent threshold. In this system paper, we solve this scalability problem by introducing a streaming system based on a sampling-reconstruction approach. First an efficient out-of-core adaptive simplification algorithm is performed in a pre-processing step, to quickly generate a simplified version of the model. The resulting model can then be submitted to arbitrary FFD tools, as its reduced size ensures interactive response. Second, a post-processing step performs a featurepreserving reconstruction of the deformation undergone by the simplified version, onto the original model. Both bracketing steps share streaming and point-based basis, making them fully scalable and compatible with pointclouds, non-manifold polygon soups and meshes. Our system also offers a generic out-of-core multi-scale layer to arbitrary FFD tools, since the two bracketing steps remain available for partial upsampling during the interactive session. As a result, arbitrarily large 3D models can be interactively edited with most FFD tools, opening the use and combination of advanced deformation metaphors to models ranging from million to billion samples. Our system also offers to work on models that fit in memory but exceed the capabilities of a given FFD tool. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Computational Geometry and Object ModelingItem Efficient Refinement of Dynamic Point Data(The Eurographics Association, 2007) Solenthaler, Barbara; Zhang, Yanci; Pajarola, Renato; M. Botsch and R. Pajarola and B. Chen and M. ZwickerParticle simulations as well as geometric modeling techniques have demonstrated their ability to process and render points interactively. However, real-time particle-based fluid simulations suffer from poor rendering quality due to low surface particle resolutions. Surfaces appear blobby, surface details are lost, and features like edges are degraded due to smoothing effects. This paper presents a novel point refinement method for irregularly sampled, dynamic points coming from a particle-based fluid simulation. Our interpolation algorithm can handle complex geometries including splashes, and at the same time preserves features like edges. Point collisions are avoided resulting in a nearly uniform sampling facilitating surface reconstruction techniques. No point preprocessing is necessary, and point neighborhoods are dynamically updated reducing computation and memory costs. We show that our algorithm can efficiently detect and refine the surface points of a fluid and we demonstrate the improvement of rendering quality and applicability to real-time simulations.Item Approximate Star-Shaped Decomposition of Point Set Data(The Eurographics Association, 2007) Lien, Jyh-Ming; M. Botsch and R. Pajarola and B. Chen and M. ZwickerSimplification or decomposition is a common strategy to handle large geometric models, which otherwise require excessive computation to process. Star-shaped decomposition partitions a model into a set of star-shaped components. A model is star shaped if and only if there exists at least one point which can see all the points of the model. Due to this interesting property, decomposing a model into star-shaped components can be used for computing camera locations to guard a given environment (the art-gallery problem), skeleton extraction, point data compression, as well as motion planning. In this paper, we propose a simple method to partition (or cluster) point set data (PSD) into 'approximately star-shaped' components. Our method can be applied to both 2D and 3D PSD and can be naturally extended to higher dimensional spaces. Our method does not require or compute any connectivity information of the input points. The proposed method only requires the position and the outward normals of points. Our experimental results show that the size of the final decomposition is close to optimal.Item Efficient Bounds for Point-Based Animations(The Eurographics Association, 2007) Steinemann, Denis; Otaduy, Miguel A.; Gross, Markus; M. Botsch and R. Pajarola and B. Chen and M. ZwickerWe introduce a new and efficient approach for collision detection in point-based animations, based on the fast computation of tight surface bounds. Our approach is able to tightly bound a high-resolution surface with a cost linear in the number of simulation nodes, which is typically small. We extend concepts about bounds of convex sets to the point-based deformation setting, and we introduce an efficient algorithm for finding extrema of these convex sets. We can compute surface bounds orders of magnitude faster and/or tighter than with previous methods.Item Efficient Point-Based Rendering Using Image Reconstruction(The Eurographics Association, 2007) Marroquim, Ricardo; Kraus, Martin; Cavalcanti, Paulo Roma; M. Botsch and R. Pajarola and B. Chen and M. ZwickerImage-space reconstruction of continuous surfaces from scattered one-pixel projections of points is known to potentially offer an advantageous time complexity compared to surface splatting techniques. We propose a new algorithm for hardware-accelerated image-space reconstruction using pull-push interpolation and present an efficient GPU implementation. Compared to published image-space reconstruction approaches employing the pull-push interpolation, our method offers a significantly improved image quality because of the integration of elliptic boxfilters and support for deferred Phong shading. For large point-based models, our GPU implementation is capable of rendering more than 50M points per second including image-space reconstruction and deferred shading.Item On the use of Gromov-Hausdorff Distances for Shape Comparison(The Eurographics Association, 2007) Memoli, Facundo; M. Botsch and R. Pajarola and B. Chen and M. ZwickerIt is the purpose of this paper to propose and discuss certain modifications of the ideas concerning Gromov- Hausdorff distances in order to tackle the problems of shape matching and comparison. These reformulations render these distances more amenable to practical computations without sacrificing theoretical underpinnings. A second goal of this paper is to establish links to several other practical methods proposed in the literature for comparing/matching shapes in precise terms. Connections with the Quadratic Assignment Problem (QAP) are also established, and computational examples are presented.Item Topological Methods for the Analysis of High Dimensional Data Sets and 3D Object Recognition(The Eurographics Association, 2007) Singh, Gurjeet; Memoli, Facundo; Carlsson, Gunnar; M. Botsch and R. Pajarola and B. Chen and M. ZwickerWe present a computational method for extracting simple descriptions of high dimensional data sets in the form of simplicial complexes. Our method, called Mapper, is based on the idea of partial clustering of the data guided by a set of functions defined on the data. The proposed method is not dependent on any particular clustering algorithm, i.e. any clustering algorithm may be used with Mapper. We implement this method and present a few sample applications in which simple descriptions of the data present important information about its structure.Item Surfel-Based Billboard Hierarchies for Fast Rendering of 3D-Objects(The Eurographics Association, 2007) Holst, Mathias; Schumann, Heidrun; M. Botsch and R. Pajarola and B. Chen and M. ZwickerIn recent years point hierarchies have been shown to be efficient for rendering high-detailed objects. Since texture access is much faster than vertex processing we propose to increase efficiency of point based rendering of arbitrary surfaces using image-based techniques. For this purpose, we combine surfels and billboards. Such a surfel billboard contains a snapshot of the geometry it represents, and can be used to replace this geometry, if the actual viewing direction is close to the direction the snapshot was taken from. Such surfel billboards can be arranged in a hierarchy to create an impostor for arbitrary view-dependant LOD. In this paper we develop a framework that contains automatic surfel billboard placement, surfel billboard hierarchy creation and a carefully adaption of texture sizes that considers probability of billboard validity and available texture memory. Furthermore, we show how surfel billboard hierarchies can be combined with traditional triangle-based multi-resolution techniques to realize a hybrid rendering with a seamless LOD-transition using a user-defined image error.Item A Parallelly Decodeable Compression Scheme for Efficient Point-Cloud Rendering(The Eurographics Association, 2007) Schnabel, Ruwen; Moeser, Sebastian; Klein, Reinhard; M. Botsch and R. Pajarola and B. Chen and M. ZwickerWe present a point-cloud compression algorithm that allows fast parallel decompression on the GPU for interactive applications. We achieve bitrates of less than four bits per normal-equipped point. Our method enables holefree level-of-detail point rendering. We also show that using only up to two bits per point, high-quality renderings can still be obtained if normals are estimated in image-space. The algorithm is based on vector quantization of an atlas of height-fields that have been sampled over primitive shapes which approximate the geometry.Item Self-Similarity-Based Compression of Point Clouds, with Application to Ray Tracing(The Eurographics Association, 2007) Hubo, Erik; Mertens, Tom; Haber, Tom; Bekaert, Philippe; M. Botsch and R. Pajarola and B. Chen and M. ZwickerMany real-world, scanned surfaces contain repetitive structures, like bumps, ridges, creases, and so on.We present a compression technique that exploits self-similarity within a point-sampled surface. Our method replaces similar surface patches with an instance of a representative patch. We use a concise shape descriptor to identify and cluster similar patches. Decoding is achieved through simple instancing of the representative patches. Encoding is efficient, and can be applied to large datasets consisting of millions of points. Moreover, our technique offers random access to the compressed data, making it applicable to ray tracing, and easily allows for storing additional point attributes, like normals.