Fast shadowing of volume data
An algorithm for fast generation of shadows in volume rendering is presented. The algorithm is an extension of a method for incremental generation of rotation sequences of volume projections. A sequence is generated as a viewer followed by a light-source moves along a circular orbit around the volume. The points in shadow in a certain projection are those that are visible from the viewers position but not from that of the light-source. The incremental method allows us to exploit the coherence between successive projections in order to reduce the number of costly raycasting operations that are neccessary to determine if points are in shadow or not. The shadowing algorithm has been implemented and tested. The results show significant reductions in computational cost compared to “brute force” generation of shadows.
Keywords3D-Volumes Volume Visualization Shadows
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- 1.Udupa J.K., ”Computer aspects of 3D imaging in medicine: a tutorial.” In 3D Imaging in Medicine (Udupa, Herman eds.), CRC Press, 1991.Google Scholar
- 2.Stytz M.R., Frieder G., Frieder O., ”Three-dimensional medical imaging: Al-gorithms and computer systems.” ACM Computing Surveys, Vol. 23, No. 4, 1991.Google Scholar
- 3.Foley J.D., van Dam A., Feiner S.K., Hughes J.F., ”Computer graphics. Principles and practice.” Addison-Wesley, 1990.Google Scholar
- 4.Levoy M., Fuchs H., Pizer S.M., Rosenman J., Chaney E.L., Sherouse G.W., Interrante V., Kiel J., ”Volume rendering in radiation treatment planning.” Proc. First Conference on Visualization in Biomedical Computing, Atlanta, Georgia, May 1990.Google Scholar
- 5.Yagel R., Kaufman A., Zhang Q., ”Realistic volume imaging.” Proc. Visualization '91, San Diego, California, October 1991.Google Scholar
- 6.Yagel R., Cohen D., Kaufman A., ”Discrete ray tracing.” IEEE Computer Graphics and Applications, Vol. 12, No. 5, September 1992.Google Scholar
- 7.Gudmundsson B., Randén M., ”Incremental generation of projections of CT-volumes.” Proc. First Conference on Visualization in Biomedical Computing, Atlanta, Georgia, May 1990.Google Scholar
- 8.Gudmundsson B., Randén M., ”Compression of sequences of 3D-volume surface projections.” Proc. XIIth International Conference on Information Processing in Medical Imaging, Wye, England, July 1991.Google Scholar
- 9.Woo A., Poulin P., Fournier A., ”A survey of shadow algorithms.” IEEE Computer Graphics and Applications, Vol. 10, No. 6, November 1990.Google Scholar