Visualizing 3D Flow with Volume Line Integral Convolution

      Since its introduction four years ago, line integral convolution [Cabral and Leedom 93] has become a very well-known and commonly used technique for visualizing 2D flow, or flow over a surface in 3D.  However, the popularity of LIC as a tool for 3D flow visualization has historically been somewhat limited, primarily due to the difficulties inherent in clearly and effectively representing dense volume textures in static, 2D images.  While at working as a staff scientist at ICASE, I investigate strategies for more effectively using 3D LIC to portray 3D flow.  Parts of this work are described in the Visualization '97 case study paper Interrante and Grosch. "Strategies for Effectively Visualizing 3D Flow with Volume LIC" (672k pdf) and in the article Interrante and Grosch, "Visualizing 3D Flow", IEEE Computer Graphics and Applications,18(4):49-53.

  The slides from this talk describe my more recent work with 3D LIC in some greater detail.
The images below highlight some of the results I was able to achieve. The flow data, generated by Dr. Chester Grosch, represents a numerical simulation of a hot, supersonic, laminar jet exiting into a colder, subsonic coflow.



It is important to let the flow define the visible surface. You can click inside the rightmost pair of images above to see mpeg animations (about 1M each) through the slices in the 3D volume.


click here for an mpeg movie- 1.7M click here for an mpeg movie- 1.6M
These side-by-side comparison images show how the use of smoothly continuous, 3D visibility-impeding halos can clarify the presentation of the flow information. Clicking on these images brings up mpeg animations (about 1.6M each).


click to see the particles move in the direction of the flow
A simple modification of the fast-LIC algorithm by [Stalling and Hege 95] allows the efficient computation of oriented 3D LIC images. This work was inspired by the example of OLIC, an oriented LIC method developed by [Wegenkittl et al. 97].



Color remains one of the best means of conveying information about related scalar quantities over a volume rendered flow. In the image above, color varies from red to yellow with increasing temperature, highlighting the effects of friction across the boundary layers in this flow.


Saturation increases with increasing streamwise vorticity across the same set of streamlines in this image, subtly emphasizing the areas of greatest turbulence. Both of these flows are rendered using halos.


In this image, color is used as an additional variable to represent the magnitude of the vorticity across the flow volume.  This particular visualization conveys the pressure waves that are being propagated down the axis of the flow.  Halos are not being used.

Last updated: 1/20/98

to my home page

This work was performed in collaboration with Dr. Chester Grosch of Old Dominion University.

References:

Brian Cabral and Casey Leedom. "Imaging Vector Fields Using Line Integral Convolution", Computer Graphics Proceedings, Annual Conference Series, 1993, pp. 263-269.
Chester Grosch, J. M. Seiner, M. Y. Hussaini, and T. L. Jackson. "Numerical Simulation of Mixing Enhancement in a Hot Supersonic Jet", Physics of Fluids, 9(4):1125-1143, 1997.
Victoria Interrante and Chester Grosch. "Strategies for Effectively Visualizing 3D Flow with Volume LIC", proceedings of Visualization '97, pp. 421-424.

Detlev Stalling and Hans-Christian Hege. "Fast and Resolution Independent Line Integral Convolution", Computer Graphics Proceedings, Annual Conference Series, 1995, pp. 249-256.

Rainer Wegenkittl, Eduard Gröller and Werner Purgathofer. "Animating Flowfields: Rendering of Oriented Line Integral Convolution", Computer Animation '97, Geneva, Switzerland, June 1997.

The views and opinions expressed in this page are strictly those of the page author.
The contents of this page have not been reviewed or approved by the University of Minnesota.