Bruce A. Robinson, Hari Viswanathan,
This study extends and applies the theory of micromixing, first introduced in the chemical reaction engineering literature, to the topic of reactive transport in porous media. For all but the simplest linear kinetic and sorption models the fate and transport of a reactive solute depends on the residence times and the details of small‐scale mixing. The latter phenomenon, also called micromixing, is important because it brings into close proximity chemical species that react, and it controls the local ...
Tópico(s): CO2 Sequestration and Geologic Interactions
2003 - Wiley | Water Resources Research
Ingo Wald, Solomon Boulos, Peter Shirley,
The most significant deficiency of most of today's interactive ray tracers is that they are restricted to static walkthroughs. This restriction is due to the static nature of the acceleration structures used. While the best reported frame rates for static geometric models have been achieved using carefully constructed kd-trees, this article shows that bounding volume hierarchies (BVHs) can be used to efficiently ray trace large static models.More importantly, the BVH can be used to ray trace deformable ...
Tópico(s): Computational Geometry and Mesh Generation
2007 - Association for Computing Machinery | ACM Transactions on Graphics
Amy L. Williams, Steve Barrus, R. Keith Morley, Peter Shirley,
Abstract The computational bottleneck in a ray tracer using bounding volume hierarchies is often the ray intersection routine with axis-aligned bounding boxes. We describe a version of this routine that uses IEEE numerical properties to ensure that those tests are both robust and efficient. Sample source code is available online.
Tópico(s): Robotics and Sensor-Based Localization
2005 - Taylor & Francis | Journal of Graphics Tools
Djamchid Ghazanfarpour, Jean‐Marc Hasenfratz,
Ray tracing is one of the most important rendering techniques used in computer graphics. A fundamental problem of classical ray tracers is the well-known aliasing. With small objects, or small shadows, aliasing becomes a crucial problem to solve. Beam tracers can be considered as an extension of classical ray tracers. They replace the concept of infinitesimal ray by that of beam but they are generally more complex than ray tracers. The new method presented in this paper is a high quality beam tracer ...
Tópico(s): Advanced Vision and Imaging
1998 - Elsevier BV | Computers & Graphics
Djamchid Ghazanfarpour, Jean‐Marc Hasenfratz,
Ray tracing is one of the most important rendering techniques used in computer graphics. A fundamental problem of classical ray tracers is the well-known aliasing. With small objects, or small shadows, aliasing becomes a crucial problem to solve. Beam tracers can be considered as an extension of classical ray tracers. They replace the concept of infinitesimal ray by that of beam but they are generally more complex than ray tracers. The new method presented in this paper is a high quality beam tracer ...
Tópico(s): 3D Shape Modeling and Analysis
1997 - Elsevier BV | Computers & Graphics
Paul W. Reimus, Catherine L. Duke, Robert Roback,
Tópico(s): Geophysical Methods and Applications
2012 - Springer Science+Business Media | Hydrogeology Journal
Kavita Bala, Julie Dorsey, Seth Teller,
This paper presents a ray tracer that facilitates near-interactive scene editing with incremental rendering; the user can edit the scene both by manipulating objects and by changing the viewpoint. Our system uses object-space radiance interpolants to accelerate ray tracing by approximating radiance, while bounding error. We introduce a new hierarchical data structure, the ray segmenttree (RST), which tracks the dependencies of radiance interpolants on regions of world space. When the scene is edited, ...
Tópico(s): Advanced Vision and Imaging
1999 - Springer Vienna | Eurographics
Sangduk Kim, Jinwoo Kim, Woo-Chan Park, Tack‐Don Han,
본 논문에서는 광선 추적기법에서 그림자 검사의 연산량을 줄이는 기법을 제안한다. 그림자 검사는 부드러운 그림자와 같이 실감 있는 영상을 생성하는 경우 광선 추적기법 렌더링 과정 중 매우 큰 비중을 차지한다. 제안하는 방식은 전처리 단계에서 kd-tree를 생성하며 계산한 그림자 정보를 기반으로 렌더링 단계에서 그림자 검사의 컬링 여부를 판별하는 방식으로 기존 렌더링 과정에 작은 변경으로 적용가능하다. 기존의 방식들과 유사하게 광원과 기하학적 구조가 변하지 않는 정적 장면에 적합하다. 사이클 정확도를 갖는 시뮬레이터를 이용하여 제안하는 방법의 유효성을 검증하고 성능을 측정하였으며 실험 결과 제안하는 그림자 컬링 기법으로 최대 17%까지 줄일 수 있다.
Tópico(s): Image and Video Quality Assessment
2013 - | Journal of Korea Game Society
David Cline, Kevin Steele, Parris K. Egbert,
... less memory. C++ source code for a ray tracer that implements LBVHs is provided online.
Tópico(s): Video Analysis and Summarization
2006 - Taylor & Francis | Journal of Graphics Tools
Qiming Hou, Hao Qin, Wenyao Li, Baining Guo, Kun Zhou,
... based micropolygon renderer. In our experiments, our ray tracer performs up to an order of magnitude faster ...
Tópico(s): Advanced Image and Video Retrieval Techniques
2010 - Association for Computing Machinery | ACM Transactions on Graphics
Eric Clément, Michel Dagenais,
... system using an efficient and accurate system level tracer, LTTng. When the tracing is finished, the individual ...
Tópico(s): Real-Time Systems Scheduling
2009 - Hindawi Publishing Corporation | Journal of Computer Networks and Communications
... quality tropospheric delays estimated by the Vienna Ray Tracer. Overall, the results indicate that our strategy based ...
Tópico(s): Advanced Frequency and Time Standards
2022 - Springer Nature | International Association of Geodesy symposia
William F. Pickard, John C. Galanis,
The term transport ionophore is introduced and defined as a membrane inclusion which facilitates the passage of ions between the two aqueous phases bounding a bilayer membrane. This concept is then used to derive formulations for the membrane currents and the undirectional ion fluxes in terms of the several species of transport ionophores (which are presumed to be biochemically unambiguous) rather than in terms of the more traditional ion-specific channels and pumps (which are commonly thought to ...
Tópico(s): Lipid Membrane Structure and Behavior
1981 - Elsevier BV | Mathematical Biosciences
Qiming Hou, Hao Qin, Wenyao Li, Baining Guo, Kun Zhou,
... based micropolygon renderer. In our experiments, our ray tracer performs up to an order of magnitude faster ...
Tópico(s): Computer Graphics and Visualization Techniques
2010 - Association for Computing Machinery | ACM Transactions on Graphics