Spring conference on Computer graphics最新文献

{"title":"Industrial application of exact Boolean operations for meshes","authors":"Martin Schifko, B. Jüttler, B. Kornberger","doi":"10.1145/1925059.1925089","DOIUrl":"https://doi.org/10.1145/1925059.1925089","url":null,"abstract":"We present an algorithm for robust Boolean operations of triangulated solids, which is suitable for real-word industrial applications involving meshes with large numbers of triangles. In order to avoid potential robustness problems, which may be caused by (almost) degenerate triangles or by intersections of nearly co-planar triangles, we use filtered exact arithmetic, based on the libraries CGAL and GNU Multi Precision Arithmetic Library. The method consists of two major steps: First we compute the exact intersection of the meshes using a sweep plane algorithm. Second we apply mesh cleaning methods which allow us to generate output which can safely be represented using floating point numbers. The performance of the method is demonstrated by several examples which are taken from applications at ECS Magna Powertrain.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"151 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132139536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneous spline surface intersections","authors":"S. Briseid, T. Dokken, T. Hagen","doi":"10.1145/1925059.1925085","DOIUrl":"https://doi.org/10.1145/1925059.1925085","url":null,"abstract":"While the PC just a few years ago included only one single-core CPU and a fixed functionality graphics card, the current commodity PC is a heterogeneous system, equipped with both a multi-core CPU and a fully programmable graphics processing unit (GPU). This change has given the commodity PC one to two orders of magnitude increase in computational performance compared with a few years ago [Brodtkorb et al. 2010; Owens et al. 2008]. We will in this paper address the potential of exploiting such a parallel computational capacity for the calculation of intersections and self-intersections of spline represented surfaces. The focus will be on massive parallel spline space refinement by knot insertion, an approach much better adapted to parallel implementations than the knot insertion used in traditional recursive subdivision based intersection algorithms. Rather than presenting a complete algorithm we address the most resource demanding sub-algorithms of surface intersection and self-intersection algorithms and their relative performance on multi-core processors and GPUs for different levels of refinement. Our results show the efficiency of the sub-algorithms on the two types of processors and how this can be used to improve the overall performance on this heterogeneous system.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123515508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parallel coordinates are better than they look!","authors":"A. Inselberg","doi":"10.1145/1925059.1925061","DOIUrl":"https://doi.org/10.1145/1925059.1925061","url":null,"abstract":"With parallel coordinates (abbr. ||-coords) the perceptual barrier imposed by our 3-dimensional habitation is breached enabling the visualization of multidimensional problems. The representation of N-dimensional points by polygonal lines is deceptively simple and additional ideas are needed to represent multivariate relations. In this talk, a panorama of highlights from the foundations to the most recent results, and interlaced with applications, are intuitively developed. This is also an opportunity to demystify some subtleties.\u0000 By learning to untangle patterns from ||-coords displays (Fig. 1, 2) a powerful knowledge discovery process has evolved. It is illustrated on a real dataset together with guidelines for exploration and good query design. Realizing that this approach is intrinsically limited (see Fig. 3 -- left) leads to a deeper geometrical insight, the recognition of M-dimensional objects recursively from their (M-- 1)-dimensional subsets (Fig. 3 -- right). Behind this striking cognitive success lies a special family of planes unique to ||-coords, the superplanes, whose points are represented by straight (rather than polygonal) lines. It emerges that any linear N-dimensionsal relation is represented by (N-- 1) indexed points. Points representing lines have two indices, points representing planes 3 indices and so on. In turn, powerful geometrical algorithms (e.g. for intersections, containment, proximities) and applications including classification Fig. 4 emerge. The classifier's power is demonstrated by obtaining a rule for the recognition of hostile vehicles from afar by their noise signature.\u0000 A smooth surface in 3-D is the envelope of its tangent planes each of which is represented by 2 points Fig. 6. As a result, a surface in 3-D is represented by two planar regions and in N-dimensions by (N-- 1) regions. This is equivalent to representing a surface by its normal vectors, rather than projections as in standard surface descriptions. Developable surfaces are represented by curves Fig. 7 revealing the surfaces' characteristics. Convex surfaces in any dimension are recognized by the hyperbola-like (i.e. having two assymptotes) regions from just one orientation Fig. 5 -- right, Fig. 8, Fig. 10 -- right. Non-orientable surfaces (i.e. like the Möbius strip) yield stunning patterns Fig. 9 unlocking new geometrical insights. Non-convexities like folds, bumps, coiling, dimples and more are no longer hidden Fig. 10 -- left and are detected from just one orientation. Evidently this representation is preferable for some applications even in 3-D. By the way, many of these results were first discovered visually and then proved mathematically; in the true spirit of Geometry.\u0000 These state of the art examples show what has been achieved on the representation of complex relations and how they generalize to N-dimensions. The patterns persist in the presence of errors deforming in ways revealing the type and magnitude of the errors and that's good news","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128843023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward image-based facial hair modeling","authors":"Tomás Lay, A. Zinke, A. Weber, T. Vetter","doi":"10.1145/1925059.1925077","DOIUrl":"https://doi.org/10.1145/1925059.1925077","url":null,"abstract":"In this paper we present a novel efficient and fully automated technique to synthesize realistic facial hair---such as beards and eyebrows---on 3D head models. The method requires registered texture images of a target model on which hair needs to be generated. In a first stage of our two-step approach a statistical measure for hair density is computed for each pixel of the texture. In addition, other geometric features such as 2D pixel orientations are extracted, which are subsequently used to generate a 3D model of the individual hair strands. Missing or incomplete information is estimated based on statistical models derived from a database of texture images of over 70 individuals. Using the new approach, characteristics of the hair extracted from a given head may be also transferred to another target.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132938171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges of volume visualization in medicine","authors":"M. Srámek","doi":"10.1145/1925059.1925064","DOIUrl":"https://doi.org/10.1145/1925059.1925064","url":null,"abstract":"Technological development has in the recent decades brought in several new imaging modalities which have significantly influenced medical diagnostics. A doctor has gained a possibility to peek inside the human body without the necessity of surgical intervention. The early variants of these techniques took advantage of classical approaches, residing in printing pictures on film transparencies. However, soon after their introduction computers started to gradually penetrate the area, with unprecedented diagnostic possibilities, but also with new challenges. A new participant entered the area - a computer scientist. Which was his/her role? Did he/she simplify the doctors life?\u0000 We will present the problem from the point of view of a computer scientist, whose task is, among others, to transform the 'high level' demands of a doctor - usually a radiologist - to a 'low level' sequence of operations for data processing and visualization. We will report on the experience gained within the framework of two projects aimed at the development of clinical applications for diagnostics of vessel pathologies of lower extremities. In the talk we will present, on the one hand, the techniques and their details and, on the other hand, we will report also on the knowledge gained in challenging collaboration within a radiological department of a hospital.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115170698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interactive reconstruction of industrial sites using parametric models","authors":"I. Reisner-Kollmann, A. Fuhrmann, W. Purgathofer","doi":"10.1145/1925059.1925079","DOIUrl":"https://doi.org/10.1145/1925059.1925079","url":null,"abstract":"We present a new interactive modeling technique for reconstructing 3D objects from multiple images. We specifically address the problems that arise in industrial environments during camera orientation, image segmentation and modeling. An accurate camera orientation is ensured by using coded markers and surveyed points from a total station. Interactive segmentations of edges and regions in the images are used as input for fitting parametric models to the scene. We provide an intuitive interface which allows modeling artificial objects without having extensive knowledge about 3D modeling or photogrammetry.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125099196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D frequency-domain analysis of non-separable reconstruction schemes by using direct volume rendering","authors":"B. Csébfalvi, B. Domonkos","doi":"10.1145/1925059.1925071","DOIUrl":"https://doi.org/10.1145/1925059.1925071","url":null,"abstract":"Recently, it has been demonstrated that the optimality of the Body-Centered Cubic (BCC) lattice can be utilized also in practice by using either non-separable box-spline filters or tensor-product B-spline filters for reconstructing an originally continuous signal from its discrete BCC-sampled representation. In order to study the frequency-domain behavior of these filters, a 3D analysis of their frequency responses is required. In this paper, we show that direct volume rendering offers a natural tool for such a 3D analysis. As the frequency responses are analytically known, their characteristic isosurfaces can be rendered separately in the pass band and in the stop band. The visualization of the frequency responses conveys information not just on the absolute postaliasing and oversmoothing effects, but also on their direction dependence. In this sense, the frequency-domain behavior of the non-separable box splines and the tensor-product B-splines on the BCC lattice is evaluated for the first time in this paper. Furthermore, we also analyze how the frequency responses are influenced by a discrete prefiltering, which is necessary to fully exploit the approximation power of the higherorder box-spline and B-spline filters.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126334863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feature-preserving mesh denoising via attenuated bilateral normal filtering and quadrics","authors":"Michal Nociar, A. Ferko","doi":"10.1145/1925059.1925086","DOIUrl":"https://doi.org/10.1145/1925059.1925086","url":null,"abstract":"In this paper, we propose a two phase feature-preserving mesh denoising algorithm. The first phase consists of modified bilateral filtering applied on field of face normals. The range filtering is affected by gradual attenuation of the standard deviation of normal differences along with subsequent iteration. We also provide a method for automatic estimation of the bilateral filter parameters without user interaction. Filtering process is followed by reconstruction of the mesh vertex positions from a given field of face normals. Our method is based on geometric fact that every vertex should lie within all tangent planes that locally support one of its neighbouring triangles. We use quadrics to encode squared distances to the planes defined by filtered normals and centroids of the faces from 1-ring neighbourhood of considered vertex. New vertex positions are identified by minimizing quadric error metric. Our tests have shown that this iteration scheme converges faster than gradient descent algorithm. Sharp features are well preserved which will be documented on several CAD-like models.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125298920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geometry and image based view quality comparison for 3D models","authors":"J. Lacko, Z. Černeková, Marian Maricak","doi":"10.1145/1925059.1925090","DOIUrl":"https://doi.org/10.1145/1925059.1925090","url":null,"abstract":"In this work we present image-based approach to the best view selection for 3D objects. The proposed method is based on entropy measured in image domain. Several 3D models are used in the experiment. The results are compared to the well-known geometrical method based on perspective frustum entropy, a special case of viewpoint entropy.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128684929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GPU-generated \"parameterized\" trees","authors":"Amit Shesh","doi":"10.1145/1925059.1925083","DOIUrl":"https://doi.org/10.1145/1925059.1925083","url":null,"abstract":"Incorporating different-looking trees in a single graphics application involves either loading numerous polygonal/point models, or generating them algorithmically. In any case, this increases the demand of rendering resources both in terms of computing power and memory to hold all models simultaneously. This paper presents a novel method that produces different-looking trees from a common domain starting from the same polygonal model. Since the shape of the canopy decides the appearance of large trees, we focus on generating canopies automatically from the same polygonal model and some parameters. Thus the generated canopies can be thought of as functions of a parameterized domain. A branch structure created separately then completes the tree model. Using this method, a program can maintain a single copy of the polygonal model, and create different tree models from it by merely changing these parameters. Our method can be efficiently implemented on a GPU, thereby allowing us to store only a few models directly in GPU memory and creating different-looking tree models from them at runtime.","PeriodicalId":235681,"journal":{"name":"Spring conference on Computer graphics","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132165316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}