Octree compression techniques have been used for several years for compressing large three dimensional data sets into homogeneous regions. This compression technique is ideally suited to datasets which have similar values in clusters. Oil engineers represent reservoirs as a three dimensional grid where hydrocarbons occur naturally in clusters. This research looks at the efficiency of storing th...

This paper presents a novel algorithm for generating a watertight level-set from an octree. We show that the levelset can be efficiently extracted regardless of the topology of the octree or the values assigned to the vertices. The key idea behind our approach is the definition of a set of binary edge-trees derived from the octree’s topology. We show that the edge-trees can be used define the p...

A progressive compression and transmission algorithm for PointTexture 3-D images is proposed in this work. The proposed algorithm represents a PointTexture image hierarchically using an octree. The geometry information in octree nodes is encoded by the predictive partial matching (PPM) method, while the color information is encoded using the discrete cosine transform (DCT). The encoder achieves...

This article presents a model for handling multiresolution animation of complex deformable models. An octree-based animation method is described, along with the set of algorithmic tools, that allow for real-time interaction on complex objects. Some efficient collision detection scheme is also described for deformable objects. A method is presented for timeguaranteed mechanical simulation, that ...

The Zoltan dynamic load balancing library provides applications with a reusable object oriented interface to several load balancing techniques, including coordinate bisection, octree/space filling curve methods, and multilevel graph partitioners. We describe enhancements to Zoltan’s octree load balancing procedure and its distributed structures that improve performance of the space filling curv...

Conservation laws are solved by a local Galerkin nite element procedure with adap-tive space-time mesh reenement and explicit time integration. The Courant stability condition is used to select smaller time steps on smaller elements of the mesh, thereby greatly increasing eeciency relative to methods having a single global time step. Processor load imbalances, introduced at adaptive enrichment ...

We present a parallel octree-based finite element method for large-scale earthquake ground motion simulation in realistic basins. The octree representation combines the low memory per node and good cache performance of finite difference methods with the spatial adaptivity to local seismic wavelengths characteristic of unstructured finite element methods. Several tests are provided to verify the...

The present paper describes an unstructured hexahedral mesh generator for viscous flow simulations around complex 3D configurations. The first step of this method is the geometric adaptation of an initial non-body-fitted mesh by grid embedding. The resulting octree mesh is then fitted to the actual boundaries of the domain and its main features, such as sharp edges and corners, are captured. De...

Numerical solutions of hyperbolic partial differential equations (PDEs) are ubiquitous in science and engineering. Method lines is a popular approach to discretize PDEs defined spacetime, where space time discretized independently. When using explicit timesteppers on adaptive grids, the use global timestep size dictated by finest grid-spacing leads inefficiencies coarser regions. Even though di...