Engineering analysis often involves the accurate numerical solution of boundary value problems in discrete form. Hierarchical quadtree (or octree) grid generation offers an efficient method for the spatial discretisation of arbitrary-shaped two- (or three-) dimensional domains. It consists of recursive algebraic splitting of sub-domains into quadrants (or cubes), leading to an ordered hierarchi...

We present a Multi-Resolution Dual method based on an incremental octree-based refinement strategy. Our solution is able to generate multi-resolution surfaces from segmented volumetric data. It extends the Dual Marching Cubes algorithm over a generalized octree and guarantees that the produced surfaces are always manifold by introducing a new cell-based criterion for dual vertices generation. M...

Algorithms are presented for moving between adjacent blocks in an octree representation of an image. Motion is possible in the direction of a face, edge, and a vertex, and between blocks of arbitrary size. The algorithms are based on a generalization and simplification of techniques developed earlier for two dimensions (i.e., in quadtrees). They are also applicable to quadtrees. The difference ...

We present a new octree-based neighborhood search method for SPH simulation. A speedup of up to 1.9x is observed in comparison state-of-the-art methods which rely on uniform grids. While our focuses maximizing performance fixed-radius simulations, we show that it can also be used scenarios where the particle support radius not constant thanks adaptive nature octree acceleration structure. Neigh...

In this paper, we investigate the performance of six data structures for managing voxelised full-waveform airborne LiDAR during 3D polygonal model creation. While has been available over a decade, extraction peak points is most widely used approach interpreting them. The increased information stored within waveform makes interpretation and handling difficult. It is, therefore, important to rese...

We present the visibility octree, a new data structure to accelerate 3D navigation through very complex scenes. Our approach employs a conservative visibility technique to compute an approximation to the visibility space partition. This approximation is computed and stored hierarchically at a preprocessing stage. We believe its main contribution to be its ability to provide an eeective control ...

We describe a method for performing color quantization on full color RGB images, using an octree data structure. The advantage of the octree is that it is simple to generate both a good partitioning of the color space and a fast inverse color table to find the color index for each pixel in the image. With only 256 colors, it is always necessary to error-diffusion dither the color for appearance...

A method for extracting intersection-free iso-surfaces from volumetric data with an octree structure is presented. Unlike contouring techniques designed for uniform grids (such as Marching Cubes), adaptive contouring methods (such as Dual Contouring) can and do often generate intersecting polygons. Our main contribution is a polygon generation algorithm that produces triangles enclosed in nonov...

Zusammenfassung. Wir präsentieren einen Methode zur Rekonstruktion vierdimensionaler Datensätze basierend auf einer Sequenz zweidimensionaler Ultraschallbilder. Da die Verlässlichkeit der rekonstruierten Daten stark von der räumlichen Verteilung der Ultraschallbilder abhängt, verwenden wir einen Octree-basierten hierarchischen Ansatz. Die Genauigkeit kann direkt aus der Auflösung der Rekonstruk...