Geodesics have a wide range of applications in CAD, shape design and machine learning. Current research on geodesic computation focuses primarily on parametric surfaces and mesh representations. There is little work on implicit surfaces. In this paper, we present a novel algorithm able to compute the exact geodesics on implicit surfaces. Although the existing Fast Marching Method can generate a...

A number of papers present algorithms to construct isosurfaces with sharp edges and corners from hermite data, i.e. the exact surface normals at the exact intersection of the surface and grid edges. We discuss some fundamental problems with the previous algorithms and describe a new approach, based on merging grid cubes near sharp edges, that produces significantly better results. Our algorithm...

Simulated through a 3D grid storing the density of clay in each cell (0 for an empty cell, and 1 for a full cell). The surface is defined as the iso-surface at 0.5 of clay density. Clay behavior is captured by a layered model ensuring 3 properties: Large scale deformations (fig.1) Mass conservation by pouring the excess of matter in neighbouring cells (fig.2) Surface tension for preventing the ...

Models and observations show that the Arctic is experiencing the most rapid changes in global near-surface air temperature. We developed novel EASE-grid Level 3 (L3) land surface temperature (LST) products from Level 2 (L2) AATSR and MODIS data to provide weekly, monthly and annual LST means over the pan-Arctic region at various grid resolutions (1–25 km) for the past decade (2000–2010). In thi...

This study describes objective analysis of the atmospheric conditions that precede or accompany severe thunderstorms and tornadoes. The data used are standard rawinsonde observations and hourly surface reports as they are transmitted over teletypewriter. In analyzing upper air data, spherical coordinates are used with grid points 2%" of lat. and long. apart. Hourly observations are analyzed on ...

A Drag Prediction Workshop was held in conjunction with the 19th AIAA Applied Aerodynamics Conference in June 2001. The purpose of the workshop was to assess the prediction of drag by computational methods for a wing/body con guration (DLR-F4) representative of subsonic transport aircraft. This report details computed results submitted to this workshop using the Reynolds-averaged Navier-Stokes ...

In February 2000 the first mission using space-borne single-pass-interferometry was launched – the Shuttle Radar Topography Mission (SRTM). The goal of the mission was to survey the Earth surface and to generate a homogeneous elevation data set of the world with a grid spacing of 1 arcsec. Antennas with two different wavelengths were used: Beside the American SIR-C the German / Italian X-SAR sy...