The increasing demand for realistic images has led to the development of several global illuminat... more The increasing demand for realistic images has led to the development of several global illumination models and rendering techniques. Great effort has been taken to extend these illumination models and optimize the rendering techniques to produce more realistic images in less time. Despite this effort, most of these methods are designed for scenes consisting of geometric surface descriptions, and cannot directly render volumetric data. Volumetric data sets can be rendered using volume rendering techniques that, in order to decrease rendering times and therefore increase interactivity, typically employ only a local illumination model. The development of global illumination models and rendering techniques for volumetric data is the focus of this work. These illumination methods can be used to generate realistic images of scenes containing volumetric as well as geometric data. The volumetric global illumination methods can be employed by a visualization system in order to add intuitive...
Annual Reliability and Maintainability Symposium. 1998 Proceedings. International Symposium on Product Quality and Integrity, 1998
Software applications Product Vision, and its successor, Galileo, were developed to allow enginee... more Software applications Product Vision, and its successor, Galileo, were developed to allow engineers to interactively fly through a digital virtual jet engine, and automatically determine removal paths for maintenance simulations. Three equally significant hurdles have been overcome during the development of this software, with the following results: state-of-the-art algorithms have been developed to find part-removal paths, create swept volumes, and decimate large models for interactive visualization. A powerful yet easy-to-use application has been developed that can efficiently manipulate large databases. The application has been integrated into many aspects of a large industrial design cycle. The application, Galileo, is being actively used by GE Aircraft Engines (GEAE). The visualization and maintainability analysis technology embedded in this software has eliminated the need for costly physical mockups and pushed maintenance issues to the earliest stages of the design cycle. The tool has facilitated concurrent engineering through visually enhanced communications. It has been adopted for aiding the assembly of engines, and for training service mechanics
Abstract Presents a system for interactively visualizing large polygonal environments such as tho... more Abstract Presents a system for interactively visualizing large polygonal environments such as those produced by CAD systems during the design of aircraft and power generation engines. Our method combines view frustum culling with level-of-detail modeling to create ...
Proceedings of Seventh Annual IEEE Visualization '96, 1996
Volume visualization techniques typically provide support for visual exploration of data, however... more Volume visualization techniques typically provide support for visual exploration of data, however additional information can be conveyed by allowing a user to see as well as feel virtual objects. In this paper we present a haptic interaction method that is suitable for both volume visualization and modeling applications. Point contact forces are computed directly from the volume data and are consistent with the isosu$ace and volume rendering methods, providing a strong correspondence behveen visual and haptic feedback. Virtual tools are simulated by applying three-dimensional jilters to some properties of the data within the extent of the tool, and interactive visual feedback rates are obtained by using an accelerated ray casting method. This haptic interaction method was implemented using a PHANTOM haptic inteeace.
VolVis is a diversified, easy to use, extensible, high performance, and portable volume visualiza... more VolVis is a diversified, easy to use, extensible, high performance, and portable volume visualization system for scientists and engineers as well as for visualization developers and researchers. VolVis accepts as input 3D scalar volumetric data as well as 3D volume-sampled and classical geometric models. Interaction with the data is controlled by a variety of 3D input devices in an input device-independent environment. VolVis output includes navigation preview, static images, and animation sequences. A variety of volume rendering algorithms are supported, ranging from fast rough approximations, to compression-domain rendering, to accurate volumetric ray tracing and radiosity, and irregular grid rendering.
ABSTRACT VolVis is a diversified, easy to use, extensible, high performance, and portable volume ... more ABSTRACT VolVis is a diversified, easy to use, extensible, high performance, and portable volume visualization system for scientists and engineers as well as for visualization developers and researchers. VolVis accepts as input 3D scalar volumetric data as well as 3D volume-sampled and classical geometric models. Interaction with the data is controlled by a variety of 3D input devices in an input device-independent environment. VolVis output includes navigation preview, static images, and animation sequences. A variety of volume rendering algorithms are supported, ranging from fast rough approximations, to compression-domain rendering, to accurate volumetric ray tracing and radiosity, and irregular grid rendering.
The VolVis system for volume visualization supports numerous visualization algorithms and methods... more The VolVis system for volume visualization supports numerous visualization algorithms and methods within a consistent and well-organized framework. Navigation and Animation components have been incorporated into VolVis which allow interactive object manipulation and quick specification of complex animation sequences. Navigation is controlled by a variety of 2D and 3D input devices. VolVis includes a unified protocol for communicating with these input devices, allowing for input device independent development.
In this paper we present an acceleration method for volumetric ray tracing which utilizes standar... more In this paper we present an acceleration method for volumetric ray tracing which utilizes standard graphics hardware without compromising image accuracy. The graphics hardware is employed to ident@ those segments of each ray that could possibly contribute to the jinal image. A volumetric ray tracing algorithm is then used to compute the$nal image, traversing only the identi$ed segments of the rays. This technique can be used to render volumetric isosurfaces as well as translucent volumes. In addition, this method can accelerate the traversal of shadow rays when performing recursive ray tracing.
fast display method for volumetric data sets is presented, which involves a slice-f based method ... more fast display method for volumetric data sets is presented, which involves a slice-f based method for extracting the potentially visible voxels to represent the visible sur aces. For a given viewing direction, the number of visible voxels can be trimmed a further by culling most of the voxels not visible from that direction. The entire 3D rray of voxels is also present for invasive operations and direct access to interior i structures. This approach has been integrated on a low-cost graphic engine as an nteractive system for craniofacial surgical planning that is currently in clinical use.
The increasing demand for realistic images has led to the development of several global illuminat... more The increasing demand for realistic images has led to the development of several global illumination models and rendering techniques. Great effort has been taken to extend these illumination models and optimize the rendering techniques to produce more realistic images in less time. Despite this effort, most of these methods are designed for scenes consisting of geometric surface descriptions, and cannot directly render volumetric data. Volumetric data sets can be rendered using volume rendering techniques that, in order to decrease rendering times and therefore increase interactivity, typically employ only a local illumination model. The development of global illumination models and rendering techniques for volumetric data is the focus of this work. These illumination methods can be used to generate realistic images of scenes containing volumetric as well as geometric data. The volumetric global illumination methods can be employed by a visualization system in order to add intuitive...
Annual Reliability and Maintainability Symposium. 1998 Proceedings. International Symposium on Product Quality and Integrity, 1998
Software applications Product Vision, and its successor, Galileo, were developed to allow enginee... more Software applications Product Vision, and its successor, Galileo, were developed to allow engineers to interactively fly through a digital virtual jet engine, and automatically determine removal paths for maintenance simulations. Three equally significant hurdles have been overcome during the development of this software, with the following results: state-of-the-art algorithms have been developed to find part-removal paths, create swept volumes, and decimate large models for interactive visualization. A powerful yet easy-to-use application has been developed that can efficiently manipulate large databases. The application has been integrated into many aspects of a large industrial design cycle. The application, Galileo, is being actively used by GE Aircraft Engines (GEAE). The visualization and maintainability analysis technology embedded in this software has eliminated the need for costly physical mockups and pushed maintenance issues to the earliest stages of the design cycle. The tool has facilitated concurrent engineering through visually enhanced communications. It has been adopted for aiding the assembly of engines, and for training service mechanics
Abstract Presents a system for interactively visualizing large polygonal environments such as tho... more Abstract Presents a system for interactively visualizing large polygonal environments such as those produced by CAD systems during the design of aircraft and power generation engines. Our method combines view frustum culling with level-of-detail modeling to create ...
Proceedings of Seventh Annual IEEE Visualization '96, 1996
Volume visualization techniques typically provide support for visual exploration of data, however... more Volume visualization techniques typically provide support for visual exploration of data, however additional information can be conveyed by allowing a user to see as well as feel virtual objects. In this paper we present a haptic interaction method that is suitable for both volume visualization and modeling applications. Point contact forces are computed directly from the volume data and are consistent with the isosu$ace and volume rendering methods, providing a strong correspondence behveen visual and haptic feedback. Virtual tools are simulated by applying three-dimensional jilters to some properties of the data within the extent of the tool, and interactive visual feedback rates are obtained by using an accelerated ray casting method. This haptic interaction method was implemented using a PHANTOM haptic inteeace.
VolVis is a diversified, easy to use, extensible, high performance, and portable volume visualiza... more VolVis is a diversified, easy to use, extensible, high performance, and portable volume visualization system for scientists and engineers as well as for visualization developers and researchers. VolVis accepts as input 3D scalar volumetric data as well as 3D volume-sampled and classical geometric models. Interaction with the data is controlled by a variety of 3D input devices in an input device-independent environment. VolVis output includes navigation preview, static images, and animation sequences. A variety of volume rendering algorithms are supported, ranging from fast rough approximations, to compression-domain rendering, to accurate volumetric ray tracing and radiosity, and irregular grid rendering.
ABSTRACT VolVis is a diversified, easy to use, extensible, high performance, and portable volume ... more ABSTRACT VolVis is a diversified, easy to use, extensible, high performance, and portable volume visualization system for scientists and engineers as well as for visualization developers and researchers. VolVis accepts as input 3D scalar volumetric data as well as 3D volume-sampled and classical geometric models. Interaction with the data is controlled by a variety of 3D input devices in an input device-independent environment. VolVis output includes navigation preview, static images, and animation sequences. A variety of volume rendering algorithms are supported, ranging from fast rough approximations, to compression-domain rendering, to accurate volumetric ray tracing and radiosity, and irregular grid rendering.
The VolVis system for volume visualization supports numerous visualization algorithms and methods... more The VolVis system for volume visualization supports numerous visualization algorithms and methods within a consistent and well-organized framework. Navigation and Animation components have been incorporated into VolVis which allow interactive object manipulation and quick specification of complex animation sequences. Navigation is controlled by a variety of 2D and 3D input devices. VolVis includes a unified protocol for communicating with these input devices, allowing for input device independent development.
In this paper we present an acceleration method for volumetric ray tracing which utilizes standar... more In this paper we present an acceleration method for volumetric ray tracing which utilizes standard graphics hardware without compromising image accuracy. The graphics hardware is employed to ident@ those segments of each ray that could possibly contribute to the jinal image. A volumetric ray tracing algorithm is then used to compute the$nal image, traversing only the identi$ed segments of the rays. This technique can be used to render volumetric isosurfaces as well as translucent volumes. In addition, this method can accelerate the traversal of shadow rays when performing recursive ray tracing.
fast display method for volumetric data sets is presented, which involves a slice-f based method ... more fast display method for volumetric data sets is presented, which involves a slice-f based method for extracting the potentially visible voxels to represent the visible sur aces. For a given viewing direction, the number of visible voxels can be trimmed a further by culling most of the voxels not visible from that direction. The entire 3D rray of voxels is also present for invasive operations and direct access to interior i structures. This approach has been integrated on a low-cost graphic engine as an nteractive system for craniofacial surgical planning that is currently in clinical use.
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Papers by Lisa Avila