High-Quality Volume Ray Casting with Extreme Point and Inflection Point Sampling

Author(s):  
Yu Chen ◽  
Liqiang Zhang ◽  
Changwen Zheng
2010 ◽  
Vol 16 (6) ◽  
pp. 1525-1532 ◽  
Author(s):  
Byeonghun Lee ◽  
Jihye Yun ◽  
Jinwook Seo ◽  
Byonghyo Shim ◽  
Yeong-Gil Shin ◽  
...  

2009 ◽  
Vol 17 (1-2) ◽  
pp. 173-184 ◽  
Author(s):  
Jusub Kim ◽  
Joseph JaJa

Interactive high quality volume rendering is becoming increasingly more important as the amount of more complex volumetric data steadily grows. While a number of volumetric rendering techniques have been widely used, ray casting has been recognized as an effective approach for generating high quality visualization. However, for most users, the use of ray casting has been limited to datasets that are very small because of its high demands on computational power and memory bandwidth. However the recent introduction of the Cell Broadband Engine (Cell B.E.) processor, which consists of 9 heterogeneous cores designed to handle extremely demanding computations with large streams of data, provides an opportunity to put the ray casting into practical use. In this paper, we introduce an efficient parallel implementation of volume ray casting on the Cell B.E. The implementation is designed to take full advantage of the computational power and memory bandwidth of the Cell B.E. using an intricate orchestration of the ray casting computation on the available heterogeneous resources. Specifically, we introduce streaming model based schemes and techniques to efficiently implement acceleration techniques for ray casting on Cell B.E. In addition to ensuring effective SIMD utilization, our method provides two key benefits: there is no cost for empty space skipping and there is no memory bottleneck on moving volumetric data for processing. Our experimental results show that we can interactively render practical datasets on a single Cell B.E. processor.


Author(s):  
Xiaobo Peng ◽  
Weihan Zhang ◽  
Sai-Gowthami Asam ◽  
Ming C. Leu

This paper presents a new method for surface reconstruction from dexel data for virtual sculpting. We are in the midst of developing a dexel model based sculpting system having the capability of interactive solid modeling with haptics interface. The geometric modeling of our sculpting system is based on the Sweep Differential Equation method to compute the boundary of the tool swept volume. Ray casting is used to perform Boolean operations between the tool swept volume and the virtual stock in dexel models to simulate the sculpting process. The dexel data are converted to a series of planar contours in parallel slices (i.e. cross sections). The overlapping ratio between two contour areas is used as the criterion for deciding on the corresponding contours in two adjacent slices. The tiling problem is tackled by using the rule of the shortest distance between points on two corresponding contours. The branching problem is solved by adding one line segment between two contours to form one composite contour. Examples are given to demonstrate the ability of the developed code to convert from dexel data to triangular meshes for the viewing of a sculpted model in different directions.


Author(s):  
Kenneth Prewitt

In the rapidly expanding sector of higher education worldwide, high quality research is disproportionately produced by a small number of research-intensive universities, probably no more than 400 worldwide. These universities are experiencing major changes, spurred by new technologies and data sources from those technologies, by the commercialization in the “knowledge economy” and competition from the for-profit private sector, and of course by opportunities and pressures of globalization itself. The phase we are in is further shaped by changes in how the state and the market set research priorities, partly by creating an accountability regime tied to timely and measurable contributions of products, services, and policies.Where does Africa fit in? It does not have competitive research-intensive universities. It does have high quality individual researchers. The author argues that its strength lies in robust regional research collaborations, coupled with serious engagement with stakeholder platforms including government, commerce, and NGOs.---Dans le secteur de l’enseignement supérieur mondial à l’expansion rapide, la recherche de grande qualité est produite disproportionnellement par un nombre restreint d’universités fortement axées sur la recherche, dont le nombre ne s’élève probablement pas à plus de 400 dans le monde entier. Ces universités sont en train de connaître des changements majeurs, déclenchés par les nouvelles technologies et les sources de données émanant de ces technologies, par la commer-cialisation dans l’ « économie du savoir » et la compétition provenant du secteur privé lucratif, et bien entendu, par des opportunités et des pressions créées par la mondialisation elle-même. La phase que nous traversons est, qui plus est, caractérisée par le changement de la manière dont l’état et le marché établissent les priorités de la recherche, partiellement en créant un régime où les instituions doivent rendre des comptes, un régime lié aux contributions opportunes et mesurables de produits, de services et de politiques.Dans ce contexte, où l’Afrique trouve-t-elle sa place ? Elle n’a pas d’universités compétitives axées fortement sur la recherche. Elle possède, néanmoins, des chercheurs individuels de grande qualité. L’auteur estime que sa force repose sur des partenariats de recherche régionaux solides, couplés à des engagements sérieux pris envers des parties prenantes comme le gouvernement, le milieu du commerce et les ONG.


2008 ◽  
Vol 28 (5) ◽  
pp. 66-77 ◽  
Author(s):  
F. Rossler ◽  
R.P. Botchen ◽  
T. Ertl

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