Painter, JS
1993
A Data Distributed, Parallel Algorithm for Ray-Traced Volume Rendering
Ma, K.-L.; Painter, J.S.; Hansen, C.D. and Krogh, M.F.
Proceedings of the 1993 Parallel Rendering Symposium, San Jose, CA, 15-22, October 1993. Funded by IBM and ACERC.
This paper presents a divide-and-conquer ray-traced volume rendering algorithm and a parallel image compositing method, along with their implementation and performance on the Connection Machine CM-5 and networked workstations. This algorithm distributes both the data and the computations to individual processing units to achieve fast, high-quality rendering of high-resolution data. The volume data, once distributed, is left intact. The processing nodes perform local raytracing of their subvolume concurrently. No communication between processing units is needed during this locally ray-tracing process. A subimage is generated by each processing unit and the final image is obtained by compositing subimages in the proper order, which can be determined a priori. Test results on the CM-5 and a group of networked workstations demonstrate the practicality of our rendering algorithm and compositing method.
1992
Parallel Volume Visualization on Workstations
Ma, K.-L. and Painter, J.S.
The International Journal of Computers and Graphics, 1992 (in press). Funded by International Business Machines and ACERC.
This paper discusses the use of general-purpose graphics workstations for interactive high-resolution volume visualization. We survey previous research results in parallel volume rendering as well as commercial products that take advantage of parallel processing to make volume rendering a practical visualization method. Our focus is on developing distributed computation methods that can distribute the memory and computational demands of volume visualization across a network of general-purpose workstations. We describe three distributed computation strategies based on ray-casting volume rendering which can be implemented on either shared-memory multiprocessor workstations or on a network of ordinary workstations. Multiple views of real-time feature extraction give tremendous insight to the volume data. Multiple variable visualization helps scientists to capture the interaction between important variables in a simulation. Divide-and-conquer rendering allows interactive high-resolution volume visualization of large data sets on a network of midrange workstations, even when the data set is too large for available memory on any single workstation. Several examples in medical imaging and computational fluid dynamics are shown illustrating the practicality of these methods.
Volume Seedlings
Cohen, M.F.; Painter, J.S.; Mehta, A.K. and Ma, K.-L.
ACM Symposium on Interactive 3-D Graphics, Cambridge, MA, March 1992. Funded by International Business Machines and ACERC.
Recent advances in software and hardware technology have made direct ray-traced volume rendering of 3-d scalar data a feasible and effective method for imaging of the data's contents. The time costs of these rendering techniques still no not permit full interaction with the data, and all of the parameters affecting the resulting images. This paper presents a set of real-time interaction techniques that have been developed to permit exploration of a volume data set. Within the limitation of a static viewpoint, the user is able to interactively alter the position and shape of an area of interest, and modify local viewing parameters. A run length encoded cache of volume rendering samples provides the means to rerender the volume at interactive rates. The use locates and plants "seeds" in areas of interest through the use of data slicing and isosurface techniques. Image processing techniques applied to volumes (i.e. volume processing), can then automatically form regions of interest that in turn modify the rendering parameters. This "region growing" of "seedlings" incrementally alters the image in real-time providing further visual cues concerning the contents of the data. These tools allow interactive exploration of internal structures in the data that may be obscured by other imaging algorithms. Magnetic Resonance Angiography (MRA) provides a driving application for this technology. Results from preliminary studies of MRA data are included.
1991
Volume Seeds: A Volume Exploration Technique
Ma, K.-L.; Cohen, M.F. and Painter, J.S.
Journal of Visualization and Computer Animation, 1991 (in press). Funded by ACERC.
Ray-traced volume rendering has been shown to be an effective method for visualizing 3-D scalar data. However, with currently available workstation technology, interactive volume exploration using conventional volume rendering is still too slow to be attractive. This paper describes an enhanced volume rendering method that allows interactive changes of rendering parameters such as color and opacity maps. An innovative technique is provided which allows the user to plant a "seed" in the volume to rapidly modify local shading parameters. For a fixed viewing position, the user can interactively explore specific regions of interest. Furthermore, a virtual cutting technique with the exploratory seed allows the user to remove surfaces and see the internal structure of the volume. Examples demonstrate these techniques as an attractive option in many applications.
Painter, JS
1993
A Data Distributed, Parallel Algorithm for Ray-Traced Volume Rendering
Ma, K.-L.; Painter, J.S.; Hansen, C.D. and Krogh, M.F.
Proceedings of the 1993 Parallel Rendering Symposium, San Jose, CA, 15-22, October 1993. Funded by IBM and ACERC.
This paper presents a divide-and-conquer ray-traced volume rendering algorithm and a parallel image compositing method, along with their implementation and performance on the Connection Machine CM-5 and networked workstations. This algorithm distributes both the data and the computations to individual processing units to achieve fast, high-quality rendering of high-resolution data. The volume data, once distributed, is left intact. The processing nodes perform local raytracing of their subvolume concurrently. No communication between processing units is needed during this locally ray-tracing process. A subimage is generated by each processing unit and the final image is obtained by compositing subimages in the proper order, which can be determined a priori. Test results on the CM-5 and a group of networked workstations demonstrate the practicality of our rendering algorithm and compositing method.
1992
Parallel Volume Visualization on Workstations
Ma, K.-L. and Painter, J.S.
The International Journal of Computers and Graphics, 1992 (in press). Funded by International Business Machines and ACERC.
This paper discusses the use of general-purpose graphics workstations for interactive high-resolution volume visualization. We survey previous research results in parallel volume rendering as well as commercial products that take advantage of parallel processing to make volume rendering a practical visualization method. Our focus is on developing distributed computation methods that can distribute the memory and computational demands of volume visualization across a network of general-purpose workstations. We describe three distributed computation strategies based on ray-casting volume rendering which can be implemented on either shared-memory multiprocessor workstations or on a network of ordinary workstations. Multiple views of real-time feature extraction give tremendous insight to the volume data. Multiple variable visualization helps scientists to capture the interaction between important variables in a simulation. Divide-and-conquer rendering allows interactive high-resolution volume visualization of large data sets on a network of midrange workstations, even when the data set is too large for available memory on any single workstation. Several examples in medical imaging and computational fluid dynamics are shown illustrating the practicality of these methods.
Volume Seedlings
Cohen, M.F.; Painter, J.S.; Mehta, A.K. and Ma, K.-L.
ACM Symposium on Interactive 3-D Graphics, Cambridge, MA, March 1992. Funded by International Business Machines and ACERC.
Recent advances in software and hardware technology have made direct ray-traced volume rendering of 3-d scalar data a feasible and effective method for imaging of the data's contents. The time costs of these rendering techniques still no not permit full interaction with the data, and all of the parameters affecting the resulting images. This paper presents a set of real-time interaction techniques that have been developed to permit exploration of a volume data set. Within the limitation of a static viewpoint, the user is able to interactively alter the position and shape of an area of interest, and modify local viewing parameters. A run length encoded cache of volume rendering samples provides the means to rerender the volume at interactive rates. The use locates and plants "seeds" in areas of interest through the use of data slicing and isosurface techniques. Image processing techniques applied to volumes (i.e. volume processing), can then automatically form regions of interest that in turn modify the rendering parameters. This "region growing" of "seedlings" incrementally alters the image in real-time providing further visual cues concerning the contents of the data. These tools allow interactive exploration of internal structures in the data that may be obscured by other imaging algorithms. Magnetic Resonance Angiography (MRA) provides a driving application for this technology. Results from preliminary studies of MRA data are included.
1991
Volume Seeds: A Volume Exploration Technique
Ma, K.-L.; Cohen, M.F. and Painter, J.S.
Journal of Visualization and Computer Animation, 1991 (in press). Funded by ACERC.
Ray-traced volume rendering has been shown to be an effective method for visualizing 3-D scalar data. However, with currently available workstation technology, interactive volume exploration using conventional volume rendering is still too slow to be attractive. This paper describes an enhanced volume rendering method that allows interactive changes of rendering parameters such as color and opacity maps. An innovative technique is provided which allows the user to plant a "seed" in the volume to rapidly modify local shading parameters. For a fixed viewing position, the user can interactively explore specific regions of interest. Furthermore, a virtual cutting technique with the exploratory seed allows the user to remove surfaces and see the internal structure of the volume. Examples demonstrate these techniques as an attractive option in many applications.