## Scale-invariant volume rendering (2005)

Venue: | In Proc. of IEEE Visualization |

Citations: | 7 - 1 self |

### BibTeX

@INPROCEEDINGS{Kraus05scale-invariantvolume,

author = {Martin Kraus},

title = {Scale-invariant volume rendering},

booktitle = {In Proc. of IEEE Visualization},

year = {2005},

pages = {295--302},

publisher = {Academic Press}

}

### OpenURL

### Abstract

Figure 1: Various kinds of isocontours: (a) isolines at equidistant isovalues on a slice; (b) standard volume rendering of isosurfaces (with gradient-dependent opacity); (c) scale-invariant volume rendering of isosurfaces with uniform opacity and (d) with silhouette enhancement As standard volume rendering is based on an integral in physical space (or “coordinate space”), it is inherently dependent on the scaling of this space. Although this dependency is appropriate for the realistic rendering of semitransparent volumetric objects, it has several unpleasant consequences for volume visualization. In order to overcome these disadvantages, a new variant of the volume rendering integral is proposed, which is defined in data space instead of physical space. Apart from achieving scale invariance, this new method supports the rendering of isosurfaces of uniform opacity and color, independently of the local gradient of the visualized scalar field. Moreover, it reveals certain structures in scalar fields even with constant transfer functions. Furthermore, it can be defined as the limit of infinitely many semitransparent isosurfaces, and is therefore based on an intuitive and at the same time precise definition. In addition to the discussion of these features of scale-invariant volume rendering, efficient adaptations of existing volume rendering algorithms and extensions for silhouette enhancement and local illumination by transmitted light are presented.

### Citations

771 | Display of surfaces from volume data
- LEVOY
- 1988
(Show Context)
Citation Context ...s that explicitly refer to non-photorealistic rendering, e.g., volume illustration by Ebert and Rheingans [1], but also for older volume rendering algorithms, e.g., the rendering of surfaces by Levoy =-=[7]-=-. In fact, without these enhancements, standard volume rendering is rather unfit for many visualization tasks. Apart from the problem of visualizing surfaces in volumetric data sets, another main chal... |

256 | Semi-automatic generation of transfer functions for direct volume rendering
- Kindlmann, JW
- 1998
(Show Context)
Citation Context ...be discussed in Sections 3 and 5.1, the former scaling results in a good approximation to the rendering of surfaces of uniform opacity with silhouette enhancement. More recently, Kindlmann and Durkin =-=[5]-=- proposed the use of multidimensional transfer functions to render material boundaries by means of volume rendering. They also suggested transfer functions that depend on the local gradient. Volume re... |

202 | High-quality preintegrated volume rendering using hardware-accelerated pixel shading
- ENGEL, KRAUS, et al.
(Show Context)
Citation Context ...olume rendering. They also suggested transfer functions that depend on the local gradient. Volume rendering of isosurfaces has received new attention in the context of pre-integrated volume rendering =-=[2, 8, 10]-=-. In fact, the pre-integrated technique for rendering isosurfaces in tetrahedral meshes suggested by Röttger et al. [10] (and later by Engel et al. [2] for texture-based volume rendering) results in i... |

167 | Volume illustration: nonphotorealistic rendering of volume models
- Rheingans, Ebert
- 2001
(Show Context)
Citation Context ...e-mail: martin kraus germany@yahoo.com of the data. This is not only true for recent approaches that explicitly refer to non-photorealistic rendering, e.g., volume illustration by Ebert and Rheingans =-=[1]-=-, but also for older volume rendering algorithms, e.g., the rendering of surfaces by Levoy [7]. In fact, without these enhancements, standard volume rendering is rather unfit for many visualization ta... |

153 | An evaluation of reconstruction filters for volume rendering
- Marschner, Lobb
(Show Context)
Citation Context ...tion is included in these examples in order to avoid unnecessary complications. Figures 8a and 8b depict a semitransparent isosurface (isovalue 0.5) in the test signal published by Marschner and Lobb =-=[9]-=-. While the scale-invariant volume rendering in Figure 8b shows plausibles(a) (b) (c) (d) (e) (f) Figure 8: (a) & (b) Isosurface in the Marschner-Lobb test signal; (c) & (d) isosurface visualizing the... |

137 |
Algorithms for realistic image synthesis
- Hall
- 1990
(Show Context)
Citation Context ...ly ignored in local volume illumination models although the transmission of light is often considered in physically based surface illumination models (see, for example, the work by Hall and Greenberg =-=[3]-=- or Rushmeier and Torrance [11]). 3 SCALE-INVARIANT INTEGRATION IN DATA SPACE In this section, a variant of the volume rendering integral in data space is proposed and its numerical evaluation in data... |

89 | Hardware-accelerated volume and isosurface rendering based on cell-projection
- Röttger, Kraus, et al.
- 2000
(Show Context)
Citation Context ...elation to previously published approaches; in particular, to the rendering of surfaces from volume data suggested by Levoy [7] and the pre-integrated isosurface rendering published by Röttger et al. =-=[10]-=-. In Section 4, the most important features of scale-invariant volume rendering are discussed. These include scale invariance, rendering of isosurfaces of uniform opacity (see also Figure 1c), viewdep... |

39 | Extending the radiosity method to include specularly reflecting and translucent materials - Rushmeier, Torrance - 1990 |

30 |
Transparency for Computer Synthesized Images
- Kay, Greenberg
- 1979
(Show Context)
Citation Context ...ring the difference between an integration in physical space and data space. One of the first techniques for silhouette enhancement of semitransparent surfaces has been published by Kay and Greenberg =-=[4]-=-. Since standard volume rendering of surfaces already results in a similar effect, silhouette enhancement has not received much interest in volume visualization. However, the adaptation of nonphotorea... |

24 | High-Quality Lighting and Efficient PreIntegration for Volume Rendering - Lum, Wilson, et al. - 2004 |

6 | Integrating preintegration into the shear-warp algorithm
- Schulze, Kraus, et al.
- 2003
(Show Context)
Citation Context ...The sampling rates required for an accurate evaluation of the scaleinvariant volume rendering integral are the same as for the standard volume rendering integral; see the discussion by Schulze et al. =-=[12]-=-. I.e., pre-integrated volume rendering requires a sampling rate high enough to accurately sample the scalar data s(x) while post-classification requires a product of this sampling rate and a sampling... |