This paper introduces a new, octree-based algorithm to assist in the automated conversion of laser scanning point cloud data into solid models appropriate for computational analysis. The focus of the work is for typical, urban, vernacular structures to assist in better damage prediction prior to tunnelling. The proposed FacadeVoxel algorithm automatically detects boundaries of building façades ...

We conceive the problem of multiple semantic video object (SVO) extraction as an issue of designing operators on a complete lattice of partitions. In this paper, we propose a framework based on accurate spatial partition generation and application of optimal extraction operators on the generated partitions. Under the framework, we introduce a spatio-temporal regional maximum likelihood operator...

Recent studies have shown that people, when asked to communicate about simple events in an improvised manner, i.e., using only gesture and no speech, consistently use a sequencing that corresponds with SOV order. We present experimental data showing that SOV is not the only order that emerges, and that intensional events give rise to a different ordering: SVO. We conclude that the semantic prop...

Discrete Global Grid data model has been widely used in digital earth. But it is only confined to the surface, and then it can not reach to the inside and outside of the earth surface. The Sphere Shell Space 3D Grid (SSSG) proposed here sets up a new spatial reference framework for the whole earth 3D space. The subdivision and coding model of SSSG is designed and carried out, which is called as...

The paper studies a method for numerical simulation of free surface flows of viscous incompressible fluids. The approach is based on the level set method for capturing free surface evolution and features compact finite difference approximations of fluid and level set equations on locally refined and dynamically adapted octree cartesian grids. We consider in detail an extension of staggered grid...

Consideration is given to the techniques required to support adaptive analysis of automatically generated unstructured meshes on distributed memory MIMD parallel computers. Emphasis is placed on the structures needed to support effective parallel computations when the numerical discretization, the mesh, is defined and evolves during the computation. The key base structures are a distributed mes...

This paper presents a method for measuring the entire three dimensional (3D) shape of object, which is applicable for 3D digitizing into a solid modeling CAD. The method measures the complete surface model of the object automatically and in the non-contact way. The method employs two range finders and a turn-table cooperatively: a fixed range finder using a turn table measures rough surface dat...

This study presents a novel rapid and effective point simplification algorithm based on point clouds without using either normal or connectivity information. Sampled points are clustered based on shape variations by octree data structure, an inner point distribution of a cluster, to judge whether these points correlate with the coplanar characteristics. Accordingly, the relevant point from each...

SP-Octrees (Space-Partition Octrees) allow a multiresolution representation of polyhedral objects, and have been successfully used in progressive transmission. Nonetheless, the SP-Octree is a solid modeling structure, intended to solve problems as solid intersections and point inclusion tests. At intermediate levels of the SP-Octree, the visualization is a rough approximation of the object due ...

The paper introduces a finite difference solver for the unsteady incompressible Navier-Stokes equations based on adaptive cartesian octree grids. The method extends a stable staggered grid finite difference scheme to the graded octree meshes. It is found that a straightforward extension is prone to produce spurious oscillatory velocity modes on the fine-to-coarse grids interfaces. A local linea...