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62
MultiResolution PointSample Raytracing
, 2003
"... We propose a new strategy for raytracing complex scenes without aliasing artifacts. The algorithm intersects anisotropic ray cones with prefiltered surface sample points from a multiresolution point hierarchy. The algorithm can be extended to capture effects of distributed raytracing [7] such as bl ..."
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Cited by 9 (0 self)
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We propose a new strategy for raytracing complex scenes without aliasing artifacts. The algorithm intersects anisotropic ray cones with prefiltered surface sample points from a multiresolution point hierarchy. The algorithm can be extended to capture effects of distributed raytracing [7] such as blurry reflections, depth of field, or soft shadows. In contrast to former antialiasing techniques based on cone tracing, the multiresolution algorithm can be applied efficiently to scenes of high complexity. The running time does not depend on the variance in the image as this is the case for the prevalent stochastic raytracing techniques. Thus, the new technique is faster than stochastic raytracing for images with many high frequency details.
Efficient PointBased Rendering using image reconstruction
, 2007
"... Imagespace reconstruction of continuous surfaces from scattered onepixel projections of points is known to potentially offer an advantageous time complexity compared to surface splatting techniques. We propose a new algorithm for hardwareaccelerated imagespace reconstruction using pullpush inte ..."
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Cited by 9 (1 self)
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Imagespace reconstruction of continuous surfaces from scattered onepixel projections of points is known to potentially offer an advantageous time complexity compared to surface splatting techniques. We propose a new algorithm for hardwareaccelerated imagespace reconstruction using pullpush interpolation and present an efficient GPU implementation. Compared to published imagespace reconstruction approaches employing the pullpush interpolation, our method offers a significantly improved image quality because of the integration of elliptic boxfilters and support for deferred Phong shading. For large pointbased models, our GPU implementation is capable of rendering more than 50 M points per second—including imagespace reconstruction and deferred shading.
A Survey of Methods for Moving Least Squares Surfaces
, 2008
"... Moving least squares (MLS) surfaces representation directly defines smooth surfaces from point cloud data, on which the differential geometric properties of point set can be conveniently estimated. Nowadays, the MLS surfaces have been widely applied in the processing and rendering of pointsampled m ..."
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Cited by 8 (0 self)
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Moving least squares (MLS) surfaces representation directly defines smooth surfaces from point cloud data, on which the differential geometric properties of point set can be conveniently estimated. Nowadays, the MLS surfaces have been widely applied in the processing and rendering of pointsampled models and increasingly adopted as the standard definition of point set surfaces. We classify the MLS surface algorithms into two types: projection MLS surfaces and implicit MLS surfaces, according to employing a stationary projection or a scalar field in their definitions. Then, the properties and constrains of the MLS surfaces are analyzed. After presenting its applications, we summarize the MLS surfaces definitions in a generic form and give the outlook of the future work at last.
Radiosity for pointsampled geometry
 In Proc. 12th Pacific Conference on Computer Graphics and Applications
, 2004
"... In this paper, we propose a radiosity method for the pointsampled geometry to compute diffuse interreflection of light. Most traditional radiosity methods subdivide the surfaces of objects into small elements such as quadrilaterals. However, the pointsampled geometry includes no explicit informati ..."
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Cited by 7 (0 self)
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In this paper, we propose a radiosity method for the pointsampled geometry to compute diffuse interreflection of light. Most traditional radiosity methods subdivide the surfaces of objects into small elements such as quadrilaterals. However, the pointsampled geometry includes no explicit information about surfaces, presenting a difficulty in applying the traditional approach to the pointsampled geometry. The proposed method addresses this problem by computing the interreflection without reconstructing any surfaces. The method realizes lighting simulations without losing the advantages of the pointsampled geometry. 1.
Hardwareaccelerated Extraction and Rendering of Point Set Surfaces
, 2006
"... Pointbased models are gaining lately considerable attention as an alternative to traditional surface meshes. In this context, Point Set Surfaces (PSS) were proposed as a modeling and rendering method with important topological and approximation properties. However, raytracing PSS is computationall ..."
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Cited by 7 (4 self)
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Pointbased models are gaining lately considerable attention as an alternative to traditional surface meshes. In this context, Point Set Surfaces (PSS) were proposed as a modeling and rendering method with important topological and approximation properties. However, raytracing PSS is computationally expensive. Therefore, we propose an interactive raytracing algorithm for PSS implemented completely on commodity graphics hardware. We also exploit the advantages of PSS to propose a novel technique for extracting surfaces directly from volumetric data. This technique is based on the well known predictorcorrector principle from the numerical methods for solving ordinary differential equations. Our technique provides good approximations to surfaces defined by a certain property in the volume, such as isosurfaces or surfaces located at regions of high gradient magnitude. Also, local details of the surfaces could be manipulated by changing the local polynomial approximation and the smoothing parameters used. Furthermore, the surfaces generated are smooth and low frequency noise is naturally handled.
Representing and Rendering Surfaces with Points
, 2003
"... This report deals with the use of points as surface rendering and modeling primitives. The main components of pointbased rendering and modeling algorithms are identified, different approaches are discussed and compared. The weaknesses of current pointbased techniques are pointed out and for some o ..."
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Cited by 7 (0 self)
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This report deals with the use of points as surface rendering and modeling primitives. The main components of pointbased rendering and modeling algorithms are identified, different approaches are discussed and compared. The weaknesses of current pointbased techniques are pointed out and for some of them a possible solution is suggested. A new algorithm for depthoffield rendering based on surface splatting is presented. It features rendering time independent of the amount of depthblur and depthoffield rendering in scenes with semitransparent surfaces. For this algorithm a mathematical analysis, an implementation and a discussion of results are given.
Computing the Inner Distances of Volumetric Models for Articulated Shape Description with a
"... Abstract—A new visibility graph based algorithm is presented for computing the inner distances of a 3D shape represented by a volumetric model. The inner distance is defined as the length of the shortest path between landmark points within the shape. The inner distance is robust to articulation and ..."
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Abstract—A new visibility graph based algorithm is presented for computing the inner distances of a 3D shape represented by a volumetric model. The inner distance is defined as the length of the shortest path between landmark points within the shape. The inner distance is robust to articulation and can reflect well the deformation of a shape structure without an explicit decomposition. Our method is based on the visibility graph approach. To check the visibility between pairwise points, we propose a novel, fast, and robust visibility checking algorithm based on a clustering technique which operates directly on the volumetric model without any surface reconstruction procedure, where an octree is used for accelerating the computation. The inner distance can be used as a replacement for other distance measures to build a more accurate description for complex shapes, especially for those with articulated parts. The binary executable program for the Windows platform is available from
Curvaturedriven modeling and rendering of pointbased surfaces
 In Braz. Symp. Comp. Graph. Imag. Proc
, 2002
"... In this work we address the problem of computing pointbased surface approximations from point clouds. Our approach is based on recently presented methods that define the approximated surface as the set of stationary points for an operator that projects points in the space onto the surface. We presen ..."
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In this work we address the problem of computing pointbased surface approximations from point clouds. Our approach is based on recently presented methods that define the approximated surface as the set of stationary points for an operator that projects points in the space onto the surface. We present a novel projection operator that differs from the defined in previous work in that it uses principal curvatures and directions approximation and an anisotropic diffusion equation to ensure an accurate approximation to the surface. We show how to estimate the principal curvatures and directions for point clouds and discuss the usefulness of the curvature information in the context of pointbased surface modeling and rendering. 1
Front tracking with movingleastsquares surfaces
 Journal of Computational Physics
"... The representation of interfaces by means of the Algebraic MovingLeastSquares (AMLS) technique is addressed. This technique, in which the interface is represented by an unconnected set of points, is interesting for evolving fluid interfaces since there is no surface connectivity. The position of t ..."
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Cited by 5 (3 self)
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The representation of interfaces by means of the Algebraic MovingLeastSquares (AMLS) technique is addressed. This technique, in which the interface is represented by an unconnected set of points, is interesting for evolving fluid interfaces since there is no surface connectivity. The position of the surface points can thus be updated without concerns about the quality of any surface triangulation. We introduce a novel AMLS technique especially designed for evolving–interfaces applications that we denote RAMLS (for Robust AMLS). The main advantages with respect to previous AMLS techniques are: increased robustness, computational efficiency, and being free of usertuned parameters. Further, we propose a new front–tracking method based on the Lagrangian advection of the unconnected point set that defines the RAMLS surface. We assume that a background Eulerian grid is defined with some grid spacing h. The advection of the point set makes the surface evolve in time. The point cloud can be regenerated at any time (in particular, we regenerate it each time step) by intersecting the gridlines with the evolved surface, which guarantees that the density of points on the surface is always well balanced. The intersection algorithm is essentially a ray–tracing algorithm, well–studied in computer graphics, in which a line (ray) is traced so as to detect all intersections with a surface. Also, the tracing of each gridline is independent and can thus be performed in parallel. Several tests are reported assessing first the accuracy of the proposed RAMLS technique, and then of the front–tracking method based on it. Comparison with previous Eulerian, Lagrangian and hybrid techniques encourage further development of the proposed method for fluid mechanics applications. 1
Hardware rendering of 3D geometry with elevation maps
 In Proc. International Conference on Shape Modeling and Applications
, 2006
"... We present a generic framework for realtime rendering of 3D surfaces. We use the common elevation map primitive, by which a given surface is decomposed into a set of patches. Each patch is parameterized as an elevation map over a planar domain and resampled on a regular grid. While current hardware ..."
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Cited by 4 (2 self)
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We present a generic framework for realtime rendering of 3D surfaces. We use the common elevation map primitive, by which a given surface is decomposed into a set of patches. Each patch is parameterized as an elevation map over a planar domain and resampled on a regular grid. While current hardware accelerated rendering approaches require conversion of this representation back into a triangle mesh or point set, we propose to render the elevation maps directly in a hardware accelerated environment. We use one base data set to render each patch in the common vertex and fragment shader pipeline. We implement meshor pointbased rendering by using a base mesh or a base point set respectively. This provides the basis for the underlying primitive for the final rendering. We show the benefits of this method for splat rendering by replacing attribute blending through a simplified and fast attribute interpolation. This results in rendering acceleration as well as an improvement in visual quality when compared to previous approaches. 1