The numerical evaluation of individual tunnel currents (pixels) constitutes the bottleneck of fast scanning tunneling microscopy (STM) imaging. The number and the position of grid points where the current is punctually evaluated have to be judiciously chosen to reveal the most important contrasts. In this note, we present an adaptive meshing approach that significantly accelerates the computati...

The DRAMA library, developed within the European Commission funded (ESPRIT) project DRAMA, supports dynamic load-balancing for parallel (message-passing) mesh-based applications. The target applications are those with dynamic and solution-adaptive features. The focus within the DRAMA project was on ®nite element simulation codes for structural mechanics. An introduction to the DRAMA library wil...

Anti-aliasing in form factor computation and precise determination of shadow boundaries are important issires for Radiosity method. A-Buffer is a technique introduced by Carpenter f o r anti-aliasing in hidden surjiace removal. In this paper, we propose a method based on the A-Bilffer to replace the Zbtlffer in the computation of form factors using the Hemicube f o r anti-aliasing. The method d...

Detecting sharp illumination variations such as shadow boundaries is an important problem for radiosity methods. Such illumination variations are captured using a nonuniform mesh that refines the areas exhibiting high illumination gradients. Nonuniform meshing techniques like discontinuity meshing often rely on shadow casting, so their application is computationally expensive. This paper presen...

This paper discusses the issues which arise when combining multigrid strategies with adaptive meshing techniques for solving steady-state problems on unstructured meshes. A basic strategy is described, and demonstrated by solving several inviscid and viscous ow cases. Potential ine ciencies in this basic strategy are exposed, and various alternate approaches are discussed, some of which are dem...

A mesh refinement procedure designed for Digital Image Correlation analyses of cracked media is proposed, based on the pixel color an artificial case, and crack opening displacement field two experimental cases. Although evidence that this can improve every case if tiny elements are sought, it also shown size matrices consequently, computational cost be reduced while maintaining accuracy, espec...

Progressive radiosity is widely used for realistic image synthesis in computer graphics applications. High-quality image generation usually requires radiosity with adaptive patch refinement to account for global illumination effects from irregular objects whose proximity varies in a 3D space. Parallelizing such an algorithm is difficult since computation cost for each object varies from one ite...

This review paper gives a detailed account of the development of mesh generation techniques on planar regions, over curved surfaces and within volumes for the past years. Emphasis will be on the generation of the unstructured meshes for purpose of complex industrial applications and adaptive refinement finite element analysis. Over planar domains and on curved surfaces, triangular and quadrilat...

We present a new algorithm, called ACSGM (which is short for Adaptive CSG Mesher), that converts scenes in CSG representation into a boundary representation (BREP) based on at triangles. The algorithm is based on the marching cube algorithm, but instead of working at a xed resolution, the size of the cubes used in the meshing process is changed adaptively. Quite diierent from the marching cube ...