The Hierarchical PRAM (H-PRAM) 5] model is a dynamically partitionable PRAM, which charges for communication and synchronization, and allows parallel algorithms to abstractly represent general locality. In this paper we show that the H-PRAM can be implemented eeciently on a two-dimensional mesh. We use the Peano indexing scheme to hierarchically partition the mesh. Multiple sub-PRAMs of the H-P...

A fundamental element of computer graphics is producing realistic visualizations of various natural phenomena. An important problem in this area is that of rendering scenes containing atmospheric effects, which arise from the absorbtion and scattering of light due to small particles such as dust and smoke. Generating photorealistic renderings through ray-tracing is computationally very demandin...

In this paper we introduce multiresolution analysis (MRA) algorithms intended to be used in scientific visualization, and based on a non-nested set of approximatingspaces. The need for non nested spaces arises from the fact that the required scaling functions do not fulfill any refinement equation. Therefore we introduce in the first part the concept of approximated refinement equation, that al...

Techniques are presented for moving between adjacent tetrahedra in a tetrahedral mesh. The tetrahedra result from a recursive decomposition of a cube into six initial congruent tetrahedra. A new technique is presented fo r labeling the triangular faces. The labeling enables the implementation of a binary-like decomposition of each tetrahedron which is represented using a pointerless representat...

The complexity of polygonal models is growing faster than the ability of graphics hardware to render them in real-time. If a scene contains many models and textures, it is often also not possible to store the entire geometry in the graphics memory. A common way to deal with such models is to use multiple levels of detail (LODs), which represent a model at different complexity levels. With view-...

We present a refinement and a coarsening (also simplification or decimation) algorithm for the adaptive representation of bivariate functions. The algorithms have proved to be efficient tools in numerical methods such as finite element method or image processing, [Pla00, Sua01b]. In this paper we particularize the algorithms and apply to the generation of levels of detail of terrain models. The...

An algorithm for non-intrusively coupling a commercial finite element software with a research code implementing a hierarchical enrichment of finite element spaces is presented. Examples of hierarchical methods supported by the algorithm are the Generalized or eXtended FEM (GFEM), the scale-bridging GFEM with numerically defined enrichment functions (GFEMgl), and the p-version of the FEM. The p...