Shear-image order ray casting volume rendering

ABSTRACT

This paper describes shear-image order ray casting, a new method for volume rendering. This method renders sampled data in three dimensions with image quality equivalent to the best of ray-per-pixel volume rendering algorithms (full image order), while at the same time retaining computational complexity and spatial coherence near to that of the fastest known algorithm (shear-warp). In shear-image order, as in shear-warp, the volume data set is resampled along slices parallel to a face of the volume. Unlike shear-warp, but like the texture-based methods, rays are cast through the centers of pixels of the image plane and sample points are at the intersections of rays with each slice. As a result, no post-warp step is required. Unlike texture methods, which realize shear and warp by transformations in a commodity graphics system, the shear-image ray casting methods use a new factorization that preserves memory and interpolation efficiency. In addition, a method is provided for accurately and efficiently embedding conventional polygon graphics and other objects into volumes. Both opaque and translucent polygons are supported.We also describe a method, included in shear-image order but applicable to other algorithms, for rendering anisotropic and sheared volume data sets directly with correct lighting.The shear-image order method has been implemented in the VolumePro^TM 1000, a single chip real-time volume rendering engine capable of processing volume data at a pipeline rate of 10⁹ samples per second. Figure 1 on the color page shows a shear-image order gallery of volumes rendered with different translucency, lighting, and some embedded geometry.

REFERENCES

• 1: Brian Cabral , Nancy Cam , Jim Foran, Accelerated volume rendering and tomographic reconstruction using texture mapping hardware, Proceedings of the 1994 symposium on Volume visualization, p.91-98, October 17-18, 1994, Tysons Corner, Virginia, United States [doi>10.1145/197938.197972]
• 2: Martin Brady , Kenneth Jung , H. T. Nguyen , Thinh Nguyen, Two-phase perspective ray casting for interactive volume navigation, Proceedings of the 8th conference on Visualization '97, p.183-ff., October 18-24, 1997, Phoenix, Arizona, United States
• 3: Klaus Engel , Martin Kraus , Thomas Ertl, High-quality pre-integrated volume rendering using hardware-accelerated pixel shading, Proceedings of the ACM SIGGRAPH/EUROGRAPHICS workshop on Graphics hardware, p.9-16, August 2001, Los Angeles, California, United States [doi>10.1145/383507.383515]
• 4: James D. Foley , Andries van Dam , Steven K. Feiner , John F. Hughes, Computer graphics: principles and practice (2nd ed.), Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1990
• 5: C. Gasparakis, Multi-resolution multi-field ray tracing: a mathematical overview, Proceedings of the conference on Visualization '99: celebrating ten years, p.199-206, October 1999, San Francisco, California, United States
• 6: Philippe Lacroute , Marc Levoy, Fast volume rendering using a shear-warp factorization of the viewing transformation, Proceedings of the 21st annual conference on Computer graphics and interactive techniques, p.451-458, July 1994 [doi>10.1145/192161.192283]
• 7: Barthold Lichtenbelt , Randy Crane , Shaz Naqvi, Introduction to volume rendering, Prentice-Hall, Inc., Upper Saddle River, NJ, 1998
• 8: Torsten Möller , Klaus Mueller , Yair Kurzion , Raghu Machiraju , Roni Yagel, Design of accurate and smooth filters for function and derivative reconstruction, Proceedings of the 1998 IEEE symposium on Volume visualization, p.143-151, October 19-20, 1998, Research Triangle Park, North Carolina, United States [doi>10.1145/288126.288189]
• 9: Hanspeter Pfister , Jan Hardenbergh , Jim Knittel , Hugh Lauer , Larry Seiler, The VolumePro real-time ray-casting system, Proceedings of the 26th annual conference on Computer graphics and interactive techniques, p.251-260, July 1999 [doi>10.1145/311535.311563]
• 10: C. Rezk-Salama , K. Engel , M. Bauer , G. Greiner , T. Ertl, Interactive volume on standard PC graphics hardware using multi-textures and multi-stage rasterization, Proceedings of the ACM SIGGRAPH/EUROGRAPHICS workshop on Graphics hardware, p.109-118, August 21-22, 2000, Interlaken, Switzerland [doi>10.1145/346876.348238]
• 11: Marc Levoy, Display of Surfaces from Volume Data, IEEE Computer Graphics and Applications, v.8 n.3, p.29-37, May 1988 [doi>10.1109/38.511]

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.1 Hardware architecture

Additional Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.3 Picture/Image Generation
      I.3.7 Three-Dimensional Graphics and Realism
  I.4 IMAGE PROCESSING AND COMPUTER VISION
        I.4.10 Image Representation

Keywords:
base plane, image order, ray casting, shear warp, shear-image order, volume rendering