Claudio Silva

Claudio Silva
University of Utah | UOU

About

35
Publications
3,800
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1,998
Citations

Publications

Publications (35)
Article
VisWeek 2010 covered the latest visualization and data analysis research and offered an excellent forum for discussing new trends in these fields.
Conference Paper
Atlas construction is an important technique in medical image analysis that plays a central role in understanding the variability of brain anatomy. The construction often requires applying image processing operations to multiple images (often hundreds of volumetric datasets), which is challenging in computational power as well as memory requirement...
Conference Paper
Full-text available
Collaboratively monitoring and analyzing large scale simulations from petascale computers is an important area of research and development within the scientific community. This paper addresses these issues when teams of colleagues from different research areas work together to help understand the complex data generated from these simulations. In pa...
Article
Efficient sorting is a key requirement for many computer science algorithms. Acceleration of existing techniques as well as developing new sorting approaches is crucial for many real-time graphics scenarios, database systems, and numerical simulations to name just a few. It is one of the most fundamental operations to organize and filter the ever g...
Conference Paper
Full-text available
Unbiased diffeomorphic atlas construction has proven to be a powerful technique for medical image analysis, particularly in brain imaging. The method operates on a large set of images, mapping them all into a common coordinate system, and creating an unbiased common template for studying intra-population variability and interpopulation differences....
Article
The first Provenance Challenge was set up in order to provide a forum for the community to help understand the capabilities of different provenance systems and the expressiveness of their provenance representations. To this end, a Functional Magnetic Resonance Imaging workflow was defined, which participants had to either simulate or run in order t...
Article
Full-text available
Comprehensive, end-to-end, data and workflow management solutions are needed to handle the increasing complexity of processes and data volumes associated with modern distributed scientific problem solving, such as ultrascale simulations and high-throughput experiments. The key to the solution is an integrated network-based framework that is functio...
Article
We describe the PVR (Parallel Volume Rendering) system, which consists of a mix of modularC/Tcl/Tk code. With PVR it is possible to balance rendering efficiency, throughput, and latencyover a large number of parallel machines configurations. It supports different rendering schemesand it can be easily augmented with others. PVR has unique capabiliti...
Article
Full-text available
We introduce a robust moving least-squares technique for reconstructing a piecewise smooth surface from a potentially noisy point cloud. We use techniques from robust statistics to guide the creation of the neighborhoods used by the moving least squares (MLS) computation. This leads to a conceptually simple approach that provides a unified framewor...
Conference Paper
Full-text available
We introduce an algorithm for constructing a high-quality triangulation directly from Point Set Surfaces. Our algorithm requires no intermediate representation and no post-processing of the output, and naturally handles noisy input data, typically in the form of a set of registered range scans. It creates a triangulation where triangle size respect...
Article
Full-text available
Progressive point set surfaces (PPSS) are a multilevel point-based surface representation. They combine the usability of mul-tilevel scalar displacement maps (e.g., compression, filtering, geometric modeling) with the generality of point-based surface representations (i.e., no fixed homology group or continuity class). The multiscale nature of PPSS...
Article
We present a sort-first parallel system for out-of-core rendering of large models on cluster-based tiled displays. The system renders high-resolution images of large models at interactive frame rates using off-the-shelf PCs with small memory. Given a model, we use an out-of-core preprocessing algorithm to build an on-disk hierarchical representatio...
Conference Paper
We present a new visibility-based prefetching algorithm for interactive out-of-core rendering of large models on an inexpensive PC. Using an approximate visibility technique, we can very accurately and efficiently determine which geometry will be visible in the near future and prefetch that geometry from disk before it must be rendered. Our prefetc...
Conference Paper
In this paper, we describe a set of 3D and 4D visualization tools and techniques for CORIE, a complex environmental observation and forecasting system (EOFS) for the Columbia River. The Columbia River, a complex and highly variable estuary, is the target of numerous cross-disciplinary ecosystem research projects and is at the heart of multiple sust...
Conference Paper
We present a sort-first parallel system for out-of-core rendering of large models on cluster-based tiled displays. The system is able to render high-resolution images of large models at interactive frame rates using off-the-shelf PCs with small memory. Given a model, we use an out-of-core preprocessing algorithm to build an on-disk hierarchical rep...
Article
Full-text available
The use of detailed geometric models is a critical factor for achieving realism in most computer graphics applications. In the past few years, we have observed an increasing demand for faithful representations of real scenes, primarily driven by applications whose goal is to create extremely realistic experiences by building virtual replicas of rea...
Conference Paper
Full-text available
This paper describes a pipeline for the acquisition and rendering of large real-world environments. In the acquisition phase, we use a laser rangefinder to capture the geometry of an environment, and a digital camera to capture its colors. In the rendering phase, we use a cluster of commodity PCs to render high-resolution images of the environment...
Article
The authors address the problem of rendering large unstructured volumetric grids on machines with limited memory. They present a set of techniquesthat can be used to render arbitrarily large data sets on machines with very little memory. The authors present results on rendering a few large data setsunder different conditions (image resolutions, mai...
Conference Paper
Full-text available
We present a unified infrastructure for parallel out-of-core isosurface extraction and volume rendering of large unstructured grids on distributed-memory parallel machines. We parallelize the out-of-core isosurface extraction algorithm of Chiang et al. (1998) and the out-of-core ZSweep technique (Farias and Silva, 2001) for direct volume rendering,...
Conference Paper
Full-text available
We advocate the use of point sets to represent shapes. We provide a definition of a smooth manifold surface from a set of points close to the original surface. The definition is based on local maps from differential geometry, which are approximated by the method of moving least squares (MLS). We present tools to increase or decrease the density of...
Conference Paper
In this paper we describe a simple parallelization of the ZSWEEP algorithm for rendering unstructured volumetric grids on distributed-shared memory machines, and study its performance on three generations of SGI multiprocessors, including the new Origin 3000 series. The main idea of the ZSWEEP algorithm is very simple; it is based on sweeping the d...
Article
Prioritized-Layered Projection (PLP) is a technique for fast rendering of high depth com- plexity scenes. It works by estimating the visible polygons of a scene from a given viewpoint incrementally, one primitive at a time. It is not a conservative technique, instead PLP is suit- able for the computation of partially correct images for use as part...
Conference Paper
We present a simple new algorithm that performs fast and memory-efficient cell projection for (exact) rendering of un- structured datasets. The main idea of the "ZSweep" algorithm is very simple; it is based on sweeping the data with a plane parallel to the viewing plane, in order of increasing z, project- ing the faces of cells that are incident t...
Conference Paper
Full-text available
Many papers have presented rendering techniques and simplification ideas with the objective of speeding up image generation for irregular grid data sets. For large data sets, however, even the current fastest algorithms are known to require seconds to generate each image, making real time analysis of such data sets very difficult, or even impossibl...
Article
Isosurface extraction is one of the most effective and powerful techniques for the investigation of volume datasets in scientific visualization. Previous isosurface techniques are all main-memory algorithms, often not applicable to large scientific visualization applications. In this paper we survey our recent work that gives the first external mem...
Article
In this paper, we consider a parallel rendering model that exploits the fundamental distinction between rendering and compositing operations, by assigning processors from specialized pools for each of these operations. Our motivation is to support the parallelization of general scan-line rendering algorithms with minimal effort, basically by suppor...
Article
We present a technique called #ow surface probes for interactive visualization of 3D steady vector #elds. The user places in the #ow #eld an arbitrarily-shapedseed surface, which is then deformed over time by the local or global 3D vector #eld, producing an animation sequence. This sequence and individual frames are used to probe the behavior of th...
Article
Direct volume rendering based on projective methods works by projecting, in visibility order, the polyhedral cells of a mesh onto the image plane, and incrementally compositing the cell’s color and opacity into the final image. Crucial to this method is the computation of a visibility ordering of the cells. If the mesh is “well-behaved” (acyclic an...
Article
Lazy Sweep Ray Casting is a fast algorithm for rendering general irregular grids. It is based on the sweep-plane paradigm, and it is able to accelerate ray casting for rendering irregular grids, including disconnected and nonconvex (even with holes) unstructured irregular grids with a rendering cost that decreases as the "disconnectedness" decrease...
Conference Paper
)Yi-Jen ChiangClaudio T. SilvayState University of New York at Stony BrookAbstractIn this paper we give I/O-optimal techniques for the extraction ofisosurfaces from volumetric data, by a novel application of the I/Ooptimalinterval tree of Arge and Vitter. The main idea is to preprocessthe dataset once and for all to build an efficient search struct...
Conference Paper
Full-text available
In researching the communication mechanisms between cells of the immune system, visualization of proteins in three dimensions can be used to determine which proteins are capable of interacting with one another at a given time by showing their spatial colocality. Volume data sets are cre- ated using digital confocal immunofluorescence micros- copy....
Conference Paper
We propose a new approach to the automatic generation of triangular irregular networks from dense terrain models. We have developed and implemented an algorithm based on the greedy principle used to compute minimum-link paths in polygons. Our algorithm works by taking greedy cuts ('bites') out of a simple closed polygon that bounds the yet-to-be tr...
Article
IntroductionIn many graphics applications, such as building walkthroughs and first-person games, theuser moves around the interior of a virtual environment and the computer creates animage for each location of the user. For any given position, the user typically sees only asmall fraction of the scene. Thus to speed up the image rendering, an applic...

Projects

Project (1)