Interactive ray tracing for volume visualization

Journal ArticleWe present a brute-force ray tracing system for interactive volume visualization, The system runs on a conventional (distributed) shared-memory multiprocessor machine. For each pixel we trace a ray through a volume to compute the color for that pixel. Although this method has high intrinsic computational cost, its simplicity and scalability make it ideal for large datasets on current high-end parallel systems

Interactive manipulation of contour data using the layers program

Journal ArticleThe "layers" program is useful for visualizing and editing large sets of contour data. These datasets arise frequently when trying to extract geometry from MRI slices. Due to the imprecise nature of the MR imaging and segmentation processes, the contours extracted may not accurately reflect the human geometry. The "layers" program has been designed to allow the efficient editing of these contours in order to provide human control over the contour generation process

Computational steering and the SCIRun integrated problem solving environment

Journal ArticleSCIRun is a problem solving environment that allows the interactive construction, debugging, and steering of large-scale scientific computations. We review related systems and introduce a taxonomy that explores different computational steering solutions. Considering these approaches, we discuss why a tightly integrated problem solving environment, such as SCIRun, simplifies the design and debugging phases of computational science applications and how such an environment aids in the scientific discovery process

Interactive volume rendering of large datasets using the silicon graphics Onyx4 visualization system

technical reportMany recent approaches to interactive volume rendering have focused on leveraging the power of commodity graphics hardware. Though currently limited to relatively small datasets, these approaches have been overwhelmingly successful. As the size of volumetric datasets continues to grow at a rapid pace, the need for scalable systems capable of interactively visualizing large datasets has emerged. In an attempt to address this need, SGI, Inc. has introduced the Silicon Graphics Onyx4 family of visualization systems. We present the results of our preliminary investigation into the utility of an 8-pipe Onyx4 system for interactive volume rendering of large datasets. By rendering the image in parallel using an application called Rhesus, we find that the Onyx4 provides reasonable interactivity for datasets that consume as much as 512 MB of texture memory

Parallelization and integration of fire simulations in the Uintah PSE

Journal ArticleA physics-based stand-alone serial code for fire simulations is integrated in a unified computational framework to couple with other disciplines and to achieve massively parallel computation. Uintah, the computational framework used, is a component-based visual problem-solving environment developed at the University of Utah. It provides the framework for large-scale parallelization for different applications. The integration of the legacy fire code in Uintah is built on three principles: 1)Develop different reusable physics-based components that can be used interchangeably and interact with other components, 2) reuse the legacy stand-alone fire code (written in Fortran) as much as possible, and 3) use components developed by third parties, specifically non-linear and linear solvers designed for solving complex-flow problems. A helium buoyant plume is simulated using the Nirvana machine at Los Alamos National Laboratory. Linear scalability is achieved up to 128 processors. Issues related to scaling beyond 128 processors are also discussed

A morphing algorithm for generating near optimal grids: applications in computational medicine

Journal ArticleWe apply morphing to t h e problem of generating the initial mesh for finite element simulations. This algorithm reduces mesh adaptation time by integrating physical and geometric constraints to provide a near optimal initial mesh. We apply this method to large-scale bioelectric field problems involving the complex geometries of the human body

Parallel methods for isosurface visualization

Journal Articleisosurface extraction and vis utilization is crucial for explorative scientific visualization of extremely large scientific data. The shear number of polygons extracted and the subsequent rendering time limit interactivity. We explore two solutions to this problem: exploiting parallel graphics hardware and parallel isosurface extraction/rendering via ray-tracing

Integrating component-based scientific computing software

Book ChapterIn recent years, component technology has been a successful methodology for large-scale commercial software development. Component technology combines a set of frequently used functions in a component and makes the implementation transparent to users. Software application developers typically connect a group of components from a component repository, connecting them to create a single application