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FAST VOLUME RENDERING USING A SHEARWARP FACTORIZATION OF THE VIEWING TRANSFORMATION
, 1995
"... Volume rendering is a technique for visualizing 3D arrays of sampled data. It has applications in areas such as medical imaging and scientific visualization, but its use has been limited by its high computational expense. Early implementations of volume rendering used bruteforce techniques that req ..."
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Cited by 442 (2 self)
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Volume rendering is a technique for visualizing 3D arrays of sampled data. It has applications in areas such as medical imaging and scientific visualization, but its use has been limited by its high computational expense. Early implementations of volume rendering used bruteforce techniques that require on the order of 100 seconds to render typical data sets on a workstation. Algorithms with optimizations that exploit coherence in the data have reduced rendering times to the range of ten seconds but are still not fast enough for interactive visualization applications. In this thesis we present a family of volume rendering algorithms that reduces rendering times to one second. First we present a scanlineorder volume rendering algorithm that exploits coherence in both the volume data and the image. We show that scanlineorder algorithms are fundamentally more efficient than commonlyused ray casting algorithms because the latter must perform analytic geometry calculations (e.g. intersecting rays with axisaligned boxes). The new scanlineorder algorithm simply streams through the volume and the image in storage order. We describe variants of the algorithm for both parallel and perspective projections and
Cube4  A Scalable Architecture for RealTime Volume Rendering
, 1996
"... We present Cube4, a specialpurpose volume rendering architecture that is capable of rendering highresolution (e.g., 1024³) datasets at 30 frames per second. The underlying algorithm, called sliceparallel raycasting, uses trilinear interpolation of samples between data slices for parallel and p ..."
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Cited by 87 (30 self)
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We present Cube4, a specialpurpose volume rendering architecture that is capable of rendering highresolution (e.g., 1024³) datasets at 30 frames per second. The underlying algorithm, called sliceparallel raycasting, uses trilinear interpolation of samples between data slices for parallel and perspective projections. The architecture uses a distributed interleaved memory, several parallel processing pipelines, and an innovative parallel dataflow scheme that requires no global communication, except at the pixel level. This leads to local, fixed bandwidth interconnections and has the benefits of high memory bandwidth, realtime data input, modularity, and scalability. We have simulated the architecture and have implemented a working prototype of the complete hardware on a configurable custom hardware machine. Our results indicate true realtime performance for highresolution datasets and linear scalability of performance with the number of processing pipelines.
Accelerating Volume Animation by SpaceLeaping
, 1993
"... f i In this paper we present a method for speeding the process of volume rendering a sequence o mages. Speedup is based on exploiting coherency between consecutive images to shorten the n path rays take through the volume. This is achieved by providing each ray with information eeded to leap over th ..."
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Cited by 66 (9 self)
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f i In this paper we present a method for speeding the process of volume rendering a sequence o mages. Speedup is based on exploiting coherency between consecutive images to shorten the n path rays take through the volume. This is achieved by providing each ray with information eeded to leap over the empty space and commence volume traversal at the vicinity of mean  b ingful data. The algorithm starts by projecting the volume into a Cbuffer (Coordinates uffer) which stores, at each pixel location, the objectspace coordinates of the first nonempty s t voxel visible from that pixel. For each change in the viewing parameters, the Cbuffer i ransformed accordingly. In the case of rotation the transformed Cbuffer goes through a pro  b cess of eliminating coordinates that possibly became hidden. The remaining values in the C uffer serve as an estimate of the point where the new rays should start their volume traverc sal. This spaceleaping method can be combined with existing accele...
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?
Differential Volume Rendering: A Fast Volume Visualization Technique for Flow Animation
, 1994
"... We present a direct volume rendering algorithm to speed up volume animation for flow visualizations. Data coherency between consecutive simulation time steps is used to avoid casting rays from those pixels retaining color values assigned to the previous image. The algorithm calculates the differenti ..."
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Cited by 39 (5 self)
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We present a direct volume rendering algorithm to speed up volume animation for flow visualizations. Data coherency between consecutive simulation time steps is used to avoid casting rays from those pixels retaining color values assigned to the previous image. The algorithm calculates the differential information among a sequence of 3D volumetric simulation data. At each time step the differential information is used to compute the locations of pixels that need updating and a raycasting method is utilized to produce the updated image. We illustrate the utility and speed of the differential volume rendering algorithm with simulation data from computational bioelectric and fluid dynamics applications. We can achieve considerable diskspace savings and nearly realtime rendering of 3D flows using lowcost, single processor workstations* for models which contain hundreds of thousands of data points.
Ray Casting Architectures for Volume Visualization
, 1999
"... Realtime visualization of large volume datasets demands high performance computation, pushing the storage, processing, and data communication requirements to the limits of current technology. General purpose parallel processors have been used to visualize moderate size datasets at interactive frame ..."
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Cited by 21 (2 self)
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Realtime visualization of large volume datasets demands high performance computation, pushing the storage, processing, and data communication requirements to the limits of current technology. General purpose parallel processors have been used to visualize moderate size datasets at interactive frame rates; however, the cost and size of these supercomputers inhibits the widespread use for realtime visualization. This paper surveys several special purpose architectures that seek to render volumes at interactive rates. These specialized visualization accelerators have cost, performance, and size advantages over parallel processors. All architectures implement ray casting using parallel and pipelined hardware. We introduce a new metric that normalizes performance to compare these architectures. The architectures included in this survey are VOGUE, VIRIM, Array Based Ray Casting, EMCube, and VIZARD II. We also discuss future applications of special purpose accelerators.
Reconstruction Error Characterization and Control: A Sampling Theory Approach
 IEEE Transactions on Visualization and Computer Graphics
, 1996
"... Reconstruction is prerequisite whenever a discrete signal needs to be resampled as a result of transformation such as texture mapping, image manipulation, volume slicing, and rendering. We present a new method for the characterization and measurement of reconstruction error in spatial domain. Our ..."
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Cited by 20 (3 self)
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Reconstruction is prerequisite whenever a discrete signal needs to be resampled as a result of transformation such as texture mapping, image manipulation, volume slicing, and rendering. We present a new method for the characterization and measurement of reconstruction error in spatial domain. Our method uses the Classical Shannon's Sampling Theorem as a basis to develop error bounds. We use this formulation to provide, for the first time, an efficient way to guarantee an error bound at every point by varying the size of the reconstruction filter. We go further to support positionadaptive reconstruction and dataadaptive reconstruction which adjust filter size to the location of reconstruction point and to the data values in its vicinity. We demonstrate the effectiveness of our methods with 1D signals, 2D signals (images), and 3D signals (volumes).  F  1I NTRODUCTION ECONSTRUCTION is the process of recovering a contin...
Volume Rendering Methods for Computational Fluid Dynamics Visualization
, 1994
"... This paper describes three alternative approaches to visualizing computational fluid dynam ics (CFD) data. One new approach uses realistic volumetric gas rendering techniques to produce photorealistic images and animations from CFD data. The second uses ray casting that is based on a simpler il ..."
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Cited by 14 (5 self)
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This paper describes three alternative approaches to visualizing computational fluid dynam ics (CFD) data. One new approach uses realistic volumetric gas rendering techniques to produce photorealistic images and animations from CFD data. The second uses ray casting that is based on a simpler illumination model and is mainly centered around a versatile new tool for the design of transfer functions. The third method employs a simple illumination model and rapid rendering mechanisms to provide ecient preview capabilities. These tools provide a large range of rendering capabilities to be used by the CFD explorer to render rapidly for navigation through the data, to emphasize data features (e.g., shock waves) with a specific transfer function, or to present a realistic rendition of the model.
Three Architectures for Volume Rendering
 COMPUTER GRAPHICS FORUM
, 1995
"... Volume rendering is a key technique in scientific visualization that lends itself to significant exploitable parallelism. The high computational demands of realtime volume rendering and continued technological advances in the area of VLSI give impetus to the development of specialpurpose volume re ..."
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Cited by 11 (6 self)
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Volume rendering is a key technique in scientific visualization that lends itself to significant exploitable parallelism. The high computational demands of realtime volume rendering and continued technological advances in the area of VLSI give impetus to the development of specialpurpose volume rendering architectures. This paper presents and characterizes three recently developed volume rendering engines which are based on the raycasting method. A taxonomy of the algorithmic variants of raycasting and details of each raycasting architecture are discussed. The paper then compares the machine features and provides an outlook on future developments in the area of volume rendering hardware.
Efficient Volume Visualization of Large Medical Datasets
"... The size of volumetric datasets used in medical environments is increasing at a rapid pace. Due to excessive precomputation and memory demanding data structures, most current approaches for volume visualization do not meet the requirements of daily clinical routine. In this diploma thesis, an appro ..."
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Cited by 9 (1 self)
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The size of volumetric datasets used in medical environments is increasing at a rapid pace. Due to excessive precomputation and memory demanding data structures, most current approaches for volume visualization do not meet the requirements of daily clinical routine. In this diploma thesis, an approach for interactive highquality rendering of large medical data is presented. It is based on imageorder raycasting with objectorder data traversal, using an optimized cache coherent memory layout. New techniques and parallelization strategies for direct volume rendering of large data on commodity hardware are presented. By using new memory efficient acceleration data structures, highquality direct volume rendering of several hundred megabyte sized datasets at subsecond frame rates on a commodity notebook is achieved.