This Article 
 Bibliographic References 
 Add to: 
Interactive Clipping Techniques for Texture-Based Volume Visualization and Volume Shading
July-September 2003 (vol. 9 no. 3)
pp. 298-312
Daniel Weiskopf, IEEE Computer Society
Thomas Ertl, IEEE Computer Society

Abstract—We propose clipping methods that are capable of using complex geometries for volume clipping. The clipping tests exploit per-fragment operations on the graphics hardware to achieve high frame rates. In combination with texture-based volume rendering, these techniques enable the user to interactively select and explore regions of the data set. We present depth-based clipping techniques that analyze the depth structure of the boundary representation of the clip geometry to decide which parts of the volume have to be clipped. In another approach, a voxelized clip object is used to identify the clipped regions. Furthermore, the combination of volume clipping and volume shading is considered. An optical model is introduced to merge aspects of surface-based and volume-based illumination in order to achieve a consistent shading of the clipping surface. It is demonstrated how this model can be efficiently incorporated in the aforementioned clipping techniques.

[1] H. Pfister, B. Lorensen, C. Bajaj, G. Kindlmann, W. Schroeder, L.S. Avila, K. Martin, R. Machiraju, and J. Lee, “The Transfer Function Bake-Off,” IEEE Computer Graphics and Applications, vol. 21, no. 3, pp. 16-22, May/June 2001.
[2] G. Kindlmann and J.W. Durkin, Semi-Automatic Generation of Transfer Functions for Direct Volume Rendering Proc. IEEE Symp. Volume Visualization, pp. 79-86, 1998.
[3] J. Kniss, G. Kindlmann, and C. Hansen, “Interactive Volume Rendering Using Multi-Dimensional Transfer Functions and Direct Manipulation Widgets,” Proc. IEEE Visualization 2001, pp. 255-262, 2001.
[4] B. Fröhlich et al., "Exploring Geo-Scientific Data in Virtual Environments," Proc. IEEE Visualization 1999, ACM Press, New York, Oct. 1999, pp. 169-173.
[5] W.R. Volz, Gigabyte Volume Viewing Using Split Software/Hardware Interpolation Proc. 2000 Symp. Volume Visualization, pp. 15-22, 2000.
[6] D. Weiskopf, K. Engel, and T. Ertl, Volume Clipping via Per-Fragment Operations in Texture-Based Volume Visualization IEEE Visualization Proc. 2002, pp. 93-100, 2002.
[7] K. Akeley, Reality Engine Graphics SIGGRAPH 1993 Conf. Proc., pp. 109-116, 1993.
[8] B. Cabral, N. Cam, and J. Foran, Accelerated Volume Rendering and Tomographic Reconstruction Using Texture Mapping Hardware Proc. 1994 Symp. Volume Visualization, pp. 91-98, 1994.
[9] C. Rezk-Salama, P. Hastreiter, C. Teitzel, and T. Ertl, “Interactive Exploration of Volume Line Integral Convolution Based on 3D-Texture Mapping,” Proc. IEEE Visualization '99, pp. 233-240, 1999.
[10] A. Van Gelder and K. Kim, Direct Volume Rendering with Shading via Three-Dimensional Textures Proc. 1996 Symp. Volume Visualization, pp. 23-30, 1996.
[11] R. Westermann and T. Ertl, Efficiently Using Graphics Hardware in Volume Rendering Applications SIGGRAPH 1998 Conf. Proc., pp. 169-179, 1998.
[12] P. Hastreiter, H. Çakmak, and T. Ertl, Intuitive and Interactive Manipulation of 3D Datasets by Integrating Texture Mapping Based Volume Rendering into the OpenInventor Class Hierarchy Bildverarbeitung für die Medizin - Algorithmen, Systeme, Anwendungen, T. Lehman, I. Scholl, and K. Spitzer, eds., pp. 149-154, Universität Aachen, Verl. d. Augustinus Buchhandlung, 1996.
[13] U. Tiede, T. Schiemann, and K.H. Höhne, High Quality Rendering of Attributed Volume Data Proc. IEEE Visualization '98, pp. 255-262, 1998.
[14] P. Bhaniramka and Y. Demange, OpenGL Volumizer: A Toolkit for High Quality Volume Rendering of Large Data Sets Proc. Volume Visualization and Graphics Symp. 2002, pp. 45-53, 2002.
[15] J. Diepstraten, D. Weiskopf, and T. Ertl, Transparency in Interactive Technical Illustrations Eurographics 2002 Conf. Proc., pp. 317-325, 2002.
[16] C. Everitt, Interactive Order-Independent Transparency white paper, NVidia, 2001.
[17] A. Mammen, "Transparency and Antialiasing Algorithms Implemented with the Virtual Pixel Maps Technique," IEEE Computer Graphics and Applications, vol. 9, no. 4, pp. 43-55, July 1989.
[18] P.J. Diefenbach, Pipeline Rendering: Interaction and Realism through Hardware-Based Multi-Pass Rendering PhD thesis, Univ. of Pennsylvania, 1996.
[19] J.D. Foley, A. van Dam, S.K. Feiner, and J.F. Hughes, Computer Graphics: Principles and Practice. Reading, Mass.: Addison-Wesley, 1990.
[20] F. Durand, 3D Visibility: Analytical Study and Applications PhD thesis, UniversitéJoseph Fourier, Grenoble I, July 1999.
[21] H. Hege, T. Höllerer, and D. Stalling, Volume Rendering Mathematical Models and Algorithmic Aspects Technical Report TR 93-7, ZIB (Konrad-Zuse-Zentrum), Berlin, 1993.
[22] N. Max, "Optical Models for Direct Volume Rendering," IEEE Trans. Visualization and Computer Graphics, Vol. 1, No. 2, June 1995, pp. 99-108.
[23] P. Sabella, A Rendering Algorithm for Visualizing 3D Scalar Fields Computer Graphics (SIGGRAPH '88 Conf. Proc.), vol. 22, no. 4, pp. 51-58, Aug. 1988.
[24] NVIDIA OpenGL Extension Specifications, M.J. Kilgard, ed., NVIDIA Corp., 2001.
[25] K. Engel, M. Kraus, and T. Ertl, High-Quality Pre-Integrated Volume Rendering Using Hardware-Accelerated Pixel Shading Proc. Eurographics/SIGGRAPH Workshop Graphics Hardware 2001, pp. 9-16, 2001.
[26] J.M. Kniss, G.L. Kindlmann, and C. Hansen, Multidimensional Transfer Functions for Interactive Volume Rendering IEEE Trans. Visualization and Computer Graphics, vol. 8, no. 3, pp. 270-285, July-Sept. 2002.
[27] J. Kniss, S. Premoze, C. Hansen, and D. Ebert, Interactive Translucent Volume Rendering and Procedural Modeling IEEE Visualization Proc. 2002, pp. 109-116, 2002.

Index Terms:
Volume rendering, volume shading, clipping, hardware acceleration.
Daniel Weiskopf, Klaus Engel, Thomas Ertl, "Interactive Clipping Techniques for Texture-Based Volume Visualization and Volume Shading," IEEE Transactions on Visualization and Computer Graphics, vol. 9, no. 3, pp. 298-312, July-Sept. 2003, doi:10.1109/TVCG.2003.1207438
Usage of this product signifies your acceptance of the Terms of Use.