Any two polygons of equal area can be partitioned into congruent sets of polygonal pieces, and in many cases one can connect the pieces by flexible hinges while still allowing the connected set to form both polygons. However it is open whether such a hinged dissection always exists. We solve a special case of this problem, by showing that any asymmetric polygon always has a hinged dissection to...

We introduce a novel mid-structure called the generalized swept mid-structure (GSM) of a closed polygonal shape, and a framework to compute it. The GSM contains both curve and surface elements and has consistent sheet-by-sheet topology, versus triangle-by-triangle topology produced by other mid-structure methods. To obtain this structure, a harmonic function, defined on the volume that is enclo...

We present G23FM, a mesh generation tool for discretizing twoand three-dimensional complex fractured geological media. G23FM includes different techniques to generate finite element grids that maintain the geometric integrity of input surfaces, and geologic data and produce optimal triangular/tetrahedral grids for flow and transport simulations. G23FM generates grid for two-dimensional cross-se...

In this work, a scheme of representation for aircraft structural concepts is identified. Based on this scheme, a parametric–associative geometrical modelling of the aeronautic structure, consisting in a quad-mapped mesh, is proposed. The mesh generation is based on a hierarchical scheme ensuring the one-to-one correspondence between mesh elements belonging to adjacent primitives. The automatic ...

3D map building is a complex robotics task which needs mathematical robust models. From a 3D point cloud, we can use the normal vectors to these points to do feature extraction. In this paper, we will present a robust method for normal estimation and unconstrained 3D-mesh generation from a not-uniformly distributed point cloud.

The facilities and services of the GEOmetry LABoratory (GEOLAB) at the NASA Langley Research Center are described. Included in this description are the laboratory functions, the surface modeling and grid generation technologies used in the laboratory, and examples of the tasks performed in the laboratory.

To produce grids conforming to the boundary of a physical domain with boundary orthogonality features, algebraic methods like transfinite interpolating schemes can be profitably used. Moreover, the coupling of Hermite-type (also interpolating prescribed boundary direction) schemes with elliptic methods turns out to be effective to overcome the drawback of both algebraic and elliptic strategies....

This work presents a method that allows the deformation of a terrain by modifying its heightmap in an augmented reality environment. The hierarchical structure of A48 meshes was used to represent terrains. This structure defines a parameter space to calculate the coordinates of a field in the R3 Euclidean space. In particular, this paper deals with the problem of modeling spherical terrains. An...

Current methods for the automatic generation of grids are reviewed. The approaches to grid generation that are discussed include cartesian, multiblock-structured, overlapping and unstructured. Emphasis is placed on those methods that can create high-quality grids appropriate for the solution of equations with a hyperbolic nature such as those that arise in fluid dynamics. Numerous figures illus...

|In this paper, an extension of the previously developed 2-D dynamic bubble system for 3-D automatic mesh generation using tetrahedral nite elements is presented. Initially, set of vertices inside the entire analysis region is generated using 3-D dynamic bubble system, followed by automatic mesh generation according to the Delaunay tessellation algorithm and the generated set of vertices. The p...