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Volume Graphics
, 1993
"... this paper, is an emerging subfield of computer , s graphics concerned with the synthesis, manipulation, and rendering of volumetric objects tored in a volume buffer of voxels. Unlike volume visualization which focuses primarily on d g sampled and computed datasets, volume graphics is concerned prim ..."
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Cited by 148 (18 self)
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this paper, is an emerging subfield of computer , s graphics concerned with the synthesis, manipulation, and rendering of volumetric objects tored in a volume buffer of voxels. Unlike volume visualization which focuses primarily on d g sampled and computed datasets, volume graphics is concerned primarily with modele eometric scenes and particularly with those that are represented in a regular volume buffer a (see also the Glossary sidebar). As an approach, volume graphics has the potential to greatly dvance the field of 3D graphics by offering a comprehensive alternative to traditional surface F graphics. igure 1 portrays the taxonomy and the dataflow of volume visualization and volume graph  z ics. In this figure the use of volume graphics techniques in various stages of volume visuali ation is marked with solid lines. The major sources of volumetric data, displayed at the top, s are sampled/computed data (on the left) and geometric models (on the right). The ampled/computed input are 3D reconstructed to fill gaps of missing information and are then a g stored in the volume buffer. The geometric model in 3D continuous space is represented by eometric formula which is 3D scanconverted (voxelized) into a set of voxels that "best"  t approximate the model and is stored in the volume buffer (see [1] Chapter 5). The fundamen als of voxelization and the related 3D discrete topology issues are presented in the Fundamentals of Voxelization sidebar.  3  F
Feature Sensitive Surface Extraction from Volume Data
"... The representation of geometric objects based on volumetric data structures has advantages in many geometry processing applications that require, e.g., fast surface interrogation or boolean operations such as intersection and union. However, surface based algorithms like shape optimization (fairing) ..."
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Cited by 120 (8 self)
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The representation of geometric objects based on volumetric data structures has advantages in many geometry processing applications that require, e.g., fast surface interrogation or boolean operations such as intersection and union. However, surface based algorithms like shape optimization (fairing) or freeform modeling often need a topological manifold representation where neighborhood information within the surface is explicitly available. Consequently, it is necessary to find effective conversion algorithms to generate explicit surface descriptions for the geometry which is implicitly defined by a volumetric data set. Since volume data is usually sampled on a regular grid with a given step width, we often observe severe alias artifacts at sharp features on the extracted surfaces. In this paper we present a new technique for surface extraction that performs feature sensitive sampling and thus reduces these alias effects while keeping the simple algorithmic structure of the standard Marching Cubes algorithm. We demonstrate the effectiveness of the new technique with a number of application examples ranging from CSG modeling and simulation to surface reconstruction and remeshing of polygonal models. 1
Rendering and Animation of Gaseous Phenomena by Combining Fast Volume and Scanline ABuffer Techniques
 Computer Graphics
, 1990
"... This paper describes a new technique that efficiently combines volume rendering and scanline abuffer techniques. This technique is useful for combining all types of volumerendered objects with scanline rendered objects and is especially useful for rendering scenes containing gaseous phenomena su ..."
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Cited by 87 (13 self)
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This paper describes a new technique that efficiently combines volume rendering and scanline abuffer techniques. This technique is useful for combining all types of volumerendered objects with scanline rendered objects and is especially useful for rendering scenes containing gaseous phenomena such as clouds, fog, and smoke. The rendering and animation of these phenomena has been a difficult problem in computer graphics. A new algorithm for realistically modeling and animating gaseous phenomena is presented, providing true threedimensional volumes of gas. The gases are modeled using turbulent flow based solid texturing to define their geometry and are animated based on turbulent flow simulations. A low albedo illumination model is used that takes into consideration selfshadowing of the volumes.
Efficient Light Propagation for Multiple Anisotropic Volume Scattering
 In Proceedings of the 5th Eurographics Workshop on Rendering
, 1994
"... Realistic rendering of participating media like clouds requires multiple anisotropic light scattering. This paper presents a propagation approximation for light scattered into M direction bins, which reduces the "ray effect" problem in the traditional "discrete ordinates" method. For a regular grid ..."
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Cited by 65 (5 self)
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Realistic rendering of participating media like clouds requires multiple anisotropic light scattering. This paper presents a propagation approximation for light scattered into M direction bins, which reduces the "ray effect" problem in the traditional "discrete ordinates" method. For a regular grid volume of n 3 elements, it takes O(M n 3 log n + M 2 n 3 ) time and O(M n 3 + M 2 ) space. This document is reprinted from the proceedings of the Fifth Eurographics Workshop on Rendering, Darmstadt, Germany, June 13  15, 1994 1. Introduction To render realistic images of clouds, one must take into account absorption and multiple scattering of incoming illumination. In addition, to produce the bright edges surrounding a cloud when the sun is behind it, one must account for the anisotropic, mainly forward, scattering of light from the water droplets. In 1984, Jim Kajiya and Brian Von Herzen [Kaj84] proposed two methods for rendering clouds. The first was the twopass "slab" me...
3D ChainMail: a Fast Algorithm for Deforming Volumetric Objects
, 1996
"... An algorithm is presented that enables fast deformation of volumetric objects. Using this algorithm,... ..."
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Cited by 64 (10 self)
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An algorithm is presented that enables fast deformation of volumetric objects. Using this algorithm,...
PriorityDriven Ray Tracing
, 1995
"... A typical ray tracing algorithm traces a ray through each screenpixel and spawns secondary rays at rayobject intersection points. Unlike traditional ray tracers which follow these rays recursively, we assign a priority value to each newly spawned ray and insert it into a priority queue. The priori ..."
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Cited by 63 (14 self)
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A typical ray tracing algorithm traces a ray through each screenpixel and spawns secondary rays at rayobject intersection points. Unlike traditional ray tracers which follow these rays recursively, we assign a priority value to each newly spawned ray and insert it into a priority queue. The priority assigned to each ray can be based on a variety of criteria, some of which we explore here. The next ray we trace is always the one with the highest priority in the queue. Occasionally, we trigger display updates when a checkpoint or predefined threshold is reached, providing intermediate images for review and evaluation. Classical ray tracers, once given the rendering specifications, are not controllable by the user. The prioritydriven ray tracing, on the other hand, provides the user with a mechanism to steer rendering and deliver intermediate images amid processing. This paper describes the illumination model of the nonrecursive prioritydriven ray tracer and evaluates its memory and ...
3D distance fields: A survey of techniques and applications
 IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS
, 2006
"... A distance field is a representation where, at each point within the field, we know the distance from that point to the closest point on any object within the domain. In addition to distance, other properties may be derived from the distance field, such as the direction to the surface, and when the ..."
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Cited by 54 (2 self)
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A distance field is a representation where, at each point within the field, we know the distance from that point to the closest point on any object within the domain. In addition to distance, other properties may be derived from the distance field, such as the direction to the surface, and when the distance field is signed, we may also determine if the point is internal or external to objects within the domain. The distance field has been found to be a useful construction within the areas of computer vision, physics, and computer graphics. This paper serves as an exposition of methods for the production of distance fields, and a review of alternative representations and applications of distance fields. In the course of this paper, we present various methods from all three of the above areas, and we answer pertinent questions such as How accurate are these methods compared to each other? How simple are they to implement?, and What is the complexity and runtime of such methods?
3d scan conversion of csg models into distance volumes
 Proc. 1998 IEEE Symposium on Volume Visualization
, 1998
"... A distance volume is a volume dataset where the value stored at each voxel is the shortest distance to the surface of the object being represented by the volume. Distance volumes are a useful representation in a number of computer graphics applications. In this paper we present a technique for gener ..."
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Cited by 46 (4 self)
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A distance volume is a volume dataset where the value stored at each voxel is the shortest distance to the surface of the object being represented by the volume. Distance volumes are a useful representation in a number of computer graphics applications. In this paper we present a technique for generating a distance volume with subvoxel accuracy from one type of geometric model, a Constructive Solid Geometry (CSG) model consisting of superellipsoid primitives. The distance volume is generated in a two step process. The first step calculates the shortest distance to the CSG model at a set of points within a narrow band around the evaluated surface. Additionally, a second set of points, labeled the zero set, which lies on the CSG model’s surface are computed. A point in the zero set is associated with each point in the narrow band. Once the narrow band and zero set are calculated, a Fast Marching Method is employed to propagate the shortest distance and closest point information out to the remaining voxels in the volume. Our technique has been used to scan convert a number of CSG models, producing distance volumes which have been utilized in a variety of computer graphics applications, e.g. CSG surface evaluation, offset surface generation, and 3D model morphing. 1
Constructive Volume Geometry
 Computer Graphics Forum
, 2000
"... We present an algebraic framework, called Constructive Volume Geometry (CVG), for modelling complex spatial objects using combinational operations. By utilising scalar fields as fundamental building blocks, CVG provides highlevel algebraic representations of objects that are defined mathematically ..."
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Cited by 45 (16 self)
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We present an algebraic framework, called Constructive Volume Geometry (CVG), for modelling complex spatial objects using combinational operations. By utilising scalar fields as fundamental building blocks, CVG provides highlevel algebraic representations of objects that are defined mathematically or built upon sampled or simulated datasets. It models amorphous phenomena as well as solid objects, and describes the interior as well as the exterior of objects. We also describe a hierarchical representation scheme for CVG, and a direct rendering method with a new approach for consistent sampling. The work has demonstrated the feasibility of combining a variety of graphics data types in a coherent modelling scheme.
Beyond Volume Rendering: Visualization, Haptic Exploration, and Physical Modeling of Voxelbased Objects
 In Proc. Eurographics workshop on Visualization in Scientific Computing
, 1995
"... visualization, but also for modeling objects and structures derived from volumetric data. The paper describes work in progress towards demonstrating the utility of a voxelbased format for modeling physical interactions between virtual objects. Data structures are presented that help to optimize sto ..."
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Cited by 36 (7 self)
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visualization, but also for modeling objects and structures derived from volumetric data. The paper describes work in progress towards demonstrating the utility of a voxelbased format for modeling physical interactions between virtual objects. Data structures are presented that help to optimize storage requirements and preserve object integrity during object movement. An adaptation to volume rendering algorithms is discussed that enables objects to be rendered individually and then combined in a final compositing step. Finally, algorithms and prototype systems are presented that use a voxelbased format to model physical interactions between objects. These physical interactions include collision detection and avoidance of object interpenetration, haptic, or tactile, exploration of virtual objects using a force feedback device, and object deformation.