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Fast Depth of Field Rendering with Surface Splatting
, 2003
"... We present a new fast algorithm for rendering the depthoffield effect for pointbased surfaces. The algorithm handles partial occlusion correctly, it does not suffer from intensity leakage and it renders depthoffield in presence of transparent surfaces. The algorithm is new in that it exploits t ..."
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We present a new fast algorithm for rendering the depthoffield effect for pointbased surfaces. The algorithm handles partial occlusion correctly, it does not suffer from intensity leakage and it renders depthoffield in presence of transparent surfaces. The algorithm is new in that it exploits the levelofdetail to select the surface detail according to the amount of depthblur applied. This makes the speed of the algorithm practically independent of the amount of depthblur. The proposed algorithm is an extension of the Elliptical Weighted Average (EWA) surface splatting. We present a mathematical analysis that extends the screen space EWA surface splatting to handle depthoffield rendering with levelofdetail, and we demonstrate the algorithm on example renderings.
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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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.
Rendering DepthofField with Surface Splatting
, 2003
"... We present a new fast algorithm for rendering the depthof field effect for pointbased surfaces. The algorithm is' able to handle partial occlusion correctly, it does not suffer from intensity leakage and it is also capable of depthoffield rendering in presence of transparent surfaces. The a ..."
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We present a new fast algorithm for rendering the depthof field effect for pointbased surfaces. The algorithm is' able to handle partial occlusion correctly, it does not suffer from intensity leakage and it is also capable of depthoffield rendering in presence of transparent surfaces. The algorithm is' new in that it exploits' the levelofdetail paradigm to select the surface detail according to the amount of depthblur applied. This' makes the speed of the algorithm practically independent of the amount of depthblur. The proposed algorithm is an extension of the Elliptical Weighted Average (EWA) surface splatting, We present a mathematical analysis that extends' the screen space EWA surface splatting to handle the depthoffield rendering, we modify the definition of surface texture to take the levelofdetail into account, allowing us' to use the levelofdetail for depthoffield rendering, and we demonstrate the algorithm on example renderings of pointbased objects'.
HardwareAssisted Visibility Ordering for PointBased and Volume Rendering
"... show the images in pairs to emphasize the absence of artifacts where the boundaries of our axes lists meet. (a) and (b) classic splatting; (c) and (d) imagebased rendering of range data with estimated depth uncertainty. In (b) and (d), Red = X axis, Blue = Z axis, Green = Y axis. This paper present ..."
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show the images in pairs to emphasize the absence of artifacts where the boundaries of our axes lists meet. (a) and (b) classic splatting; (c) and (d) imagebased rendering of range data with estimated depth uncertainty. In (b) and (d), Red = X axis, Blue = Z axis, Green = Y axis. This paper presents a method to accelerate algorithms that need a correct and complete visibility ordering of their data for rendering. The technique works by first presorting primitives using three lists one for each axis, and then combining them using graphics hardware, by either clipping the projected primitives while rendering, according to the current list being processed, or by rendering each list to a texture and merging the textures in the end. We show that our algorithm works by applying it to the splatting technique using several types of rendering, including classic splatting and volume rendering. 1.
ImageBased Rendering of Range Data with Depth Uncertainty By
"... ImageBased Rendering is an exciting new field, which lies in between Computer Graphics and Computer Vision. We believe that the more we use the knowledge from Computer Vision in our graphics rendering algorithms, the better our final rendered images will be. This dissertation presents a framework t ..."
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ImageBased Rendering is an exciting new field, which lies in between Computer Graphics and Computer Vision. We believe that the more we use the knowledge from Computer Vision in our graphics rendering algorithms, the better our final rendered images will be. This dissertation presents a framework to identify what information from computer vision is relevant for rendering and how to render it. Instead of only using the depth information per pixel, we compute what we call a depth uncertainty region around it. We show how to compute this region from an existing 3D recovering algorithm called rangespace search. We also present a new idea that further improve the uncertainty estimation, making it tighter. It is based on the assumption that the estimated depth is close enough to the actual surface. Two approaches for rendering are presented. The 4D approach is based on the light field ray space parameterization. The 3D approach is based on an existing technique of splatting 3D Gaussian kernels. We show that both techniques achieve good results, but the 3D approach is faster and it produces sharper images in most cases.
Silhouette Enhanced PointBased Rendering
"... With the recent advances in the 3D scanning field, the size of datasets to be displayed has increased up to billions of points. Typically, we have a dense, unstructured set of points without connectivity information. Most researchers have proposed the pointsurfel association to represent the surfac ..."
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With the recent advances in the 3D scanning field, the size of datasets to be displayed has increased up to billions of points. Typically, we have a dense, unstructured set of points without connectivity information. Most researchers have proposed the pointsurfel association to represent the surface’s geometry and to render it using a planar approximation for each point. This paper proposes an alternative approximation, where curved surface elements (csurfels) are employed, in order to get better adaptation to the surface to be rendered. We also use texture mapping and blending, to produce a perceptually better visualization. Improvements caused by using curved surfels instead of planar ones are especially noticeable at the object’s silhouette.
Abstract A Hardware Architecture for
"... We present a novel architecture for hardwareaccelerated rendering of point primitives. Our pipeline implements a refined version of EWA splatting, a high quality method for antialiased rendering of point sampled representations. A central feature of our design is the seamless integration of the arc ..."
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We present a novel architecture for hardwareaccelerated rendering of point primitives. Our pipeline implements a refined version of EWA splatting, a high quality method for antialiased rendering of point sampled representations. A central feature of our design is the seamless integration of the architecture into conventional, OpenGLlike graphics pipelines so as to complement trianglebased rendering. The specific properties of the EWA algorithm required a variety of novel design concepts including a ternary depth test and using an onchip pipelined heap data structure for making the memory accesses of splat primitives more coherent. In addition, we developed a computationally stable evaluation scheme for perspectively corrected splats. We implemented our architecture both on reconfigurable FPGA boards and as an ASIC prototype, and we integrated it into an OpenGLlike software implementation. Our evaluation comprises a detailed performance analysis using scenes of varying complexity.
Simon Mall ∗
"... We present a novel architecture for hardwareaccelerated rendering of point primitives. Our pipeline implements a refined version of EWA splatting, a high quality method for antialiased rendering of point sampled representations. A central feature of our design is the seamless integration of the arc ..."
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We present a novel architecture for hardwareaccelerated rendering of point primitives. Our pipeline implements a refined version of EWA splatting, a high quality method for antialiased rendering of point sampled representations. A central feature of our design is the seamless integration of the architecture into conventional, OpenGLlike graphics pipelines so as to complement trianglebased rendering. The specific properties of the EWA algorithm required a variety of novel design concepts including a ternary depth test and using an onchip pipelined heap data structure for making the memory accesses of splat primitives more coherent. In addition, we developed a computationally stable evaluation scheme for perspectively corrected splats. We implemented our architecture both on reconfigurable FPGA boards and as an ASIC prototype, and we integrated it into an OpenGLlike software implementation. Our evaluation comprises a detailed performance analysis using scenes of varying complexity.
by Anil Kumar Kanakanti Roll No: 05305805
, 2007
"... In recent years pointbased geometry has gained increasing attention as an alternative surface representation, both for efficient rendering and for flexible geometry processing of highly complex 3Dmodels. Based on their fundamental simplicity, points have motivated a variety of research on topics s ..."
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In recent years pointbased geometry has gained increasing attention as an alternative surface representation, both for efficient rendering and for flexible geometry processing of highly complex 3Dmodels. Based on their fundamental simplicity, points have motivated a variety of research on topics such as shape modeling, object capturing, simplification, rendering and hybrid pointpolygon methods. Rendering the points is inherently a big problem due to lack of connectivity information. But lack of connectivity introduces several artifacts while in the process of rendering like aliasing and holes in the rendered model. In this report we will discuss several rendering algorithms and a new point rendering algorithm, a combination of ideas from different algorithms which includes advantages of different algorithms to give high quality rendering. Point clouds are not always feasible for real world model representation because of over sampling of planar surfaces and undersampling of high curvature parts of the model which results huge storage costs and more processing time. In this report we will also discuss a point cloud simplification algorithm which simplifies input point model by using clustering techniques. 1
The Use of FreeForm Deformation for Correcting the Taphonomic Distortions of Fossilized Hominid Crania
"... This paper describes a technique for correcting the plastic distortion that fossilized crania found in South Africa are typically effected by. This distortion is caused by the collapse of the caves in which the fossils are deposited. The fossils are digitized using photogrammetry, resulting in a poi ..."
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This paper describes a technique for correcting the plastic distortion that fossilized crania found in South Africa are typically effected by. This distortion is caused by the collapse of the caves in which the fossils are deposited. The fossils are digitized using photogrammetry, resulting in a point cloud of surface positions. These positions then undergo statistical analysis (linear regression models) to determine their correct Cartesian location with respect to each other. Warping techniques are then used to correctly shape the skull.