Volume rendering

For presenting the results of the 3D-CT measurements the software tool 3D-CTViewer [12] was designed and developed under the visualization developer language IDL [13]. In this package both typical methods for 3D-visualization, the surface and the volume rendering technique [14], are implemented. 

The method of volume rendering uses the whole sample volume for visualization. Therefor semitransparent representations of the samples inner structure are possible and the detection of small cracks or faults is much easier compared to the surfaces based techniques (Fig. 4 b). From its principle volume rendering is more time consuming compared to surface representation. 

Volume rendering of scalar dissipation rate in a DNS of a temporally evolving CO/Hj jet flame. Re = 9200 [16]. The highest values of scalar dissipation rate (shown in red) exceed 30,000 S . ... 

Volume rendering is a technique for displaying a sampled 3D scalar field directly, without first fitting geometric primitives to the samples. It is a recon-... 

Figure 2 Volume visualization of the three-dimensional volume representing the PVC-enriched phase of the polymer blend (a) the whole volume rendered, (b) three orthogonal slices showing the interior of the volume, (c) single isosurface showing 5/95 PVC/PMMA composition of the blend, and (d) multiple isosurfaces displaying three compositions 5/95, 12/88, and 22/78 of the blend. Reproduced from Artyushkova and Fulghum [9].

Lucas L, Gilbert N, Ploton D, Bonnet N. Visualisation of volume data in confocal microscopy comparison and improvements of volume-rendering methods. JMicrosc 1996 181 238-252. 

Fig. 3. Skeletal and soft tissue anatomical features can be scrutinized and labeled for compilation purposes. (Left) A rat gestational day 21 (GD21) skeletal specimen, 3D volume rendering. (Middle) fsA PO specimen with on-screen thresholding optimized to detail the skeletal features of inferesf. (Right) The same rat PO specimen, processed for soff fissue visualization, with relevant soft tissue features of inferesf highlighted.

Valentino, D.J., Mazziota, J.C., Huang, H.K. (1991). Volume rendering of multimodal images Applications to MRI and PET imaging of the human brain. IEEE Trans. Med. Imaging 10,554-562. 

Figure 43 Volume rendering of D secondary ion distribution from a Zr02/Zr-2.5 Nb sample. Field of view is 150 pm depth is 10 pm. (From Ref. 134.)...

Alternatively, 3D images of MR angiographies can be calculated using volume rendering techniques (VRT) or shaded surface display (SSD). Both methods, however, depend on threshold values and therefore they carry the risk of unwanted manipulation. They are less suitable for the depiction of stenoses and are commonly used for aneurysms and other vascular malformations. 

AnalyzeAVW Volume Renderer. To improve liver segmentation at later time points, follow-up scans can be registered to the baseline scans (Hajnal et al. 1995). 

Plate 1 (A) Normal case coronary angiography (left) and three-dimensional volume rendering of CMDCT (right) showing normal LAD and LCX artery. The latter is partially covered by left appendix in CMDCT. The arrow points out LAD. 

Scientific visualization deals with visualizing large data sets. Both raw, derived and calculated data can be visualized. Large systems such as weather data (real data) and results of aerodynamic calculations (calculated data) are used frequently [Nielson et al. 1990, Jones 1996, Cleveland 1985, Cleveland McGill 1988], Scientific visualization uses images, color, volume rendering by interpolation, special symbols and animation. Sound is also included if appropriate. In this book, color is not used and animation is impossible with static figures, but they certainly have a future for visualization in three-way analysis. 

Fig. 15. Volume rendering of a Pt/TUD-1 Fig. 16. Projection of the reconstructed volume of particle (height 216 run) showing the 3D PdRu/MCM-41 showing the hexagonal order of the mesopore network in orange with Pt particles mesopores and the metal particles [16]. in red.

Fig. 18. Rendering of an Au/SBA-15 particle (256x256x166 nm3) at two different orientations, i.e. side on view of the pores (volume rendering, a) and parallel to the pores (surface rendering, b).

Fig. 4.2 Dedicated animal X-ray computed tomography system that allows high-resolution imaging (up to 18 pm) of rodents. The different attenuation ofX-rays in various tissues and bones allows volume rendering of the different structures (right image) (Courtesy of ImTek, Inc., Knoxville, TN, USA).

Figure 11.3 Instantaneous flow visualizations (a) and volume renderings of the vorticity magnitude Q (b) for S = 0.56 LM-6000 (top), turbulent pipe flow (bottom). Instantaneous visualizations involve axial velocity levels between —0.33t o (dark blue) and Uo (dark red) and vorticity values between —RK lUo) (blue) and - -Rj(2Uo) (red) more details are in [6]. (Refer color plate, p. IX.)...

---