Project-Team Vegas Effective Geometric Algorithms for Surfaces and Visibility

Project-Team VEGAS Effective Geometric Algorithms for Visibility and Surfaces

Project-Team VEGAS Effective Geometric Algorithms for Visibility and Surfaces

Tangent, normal, and visibility cones on Bézier surfaces

Definitions and properties for three types of cones, i.e., tangent, normal and visibility cones for regular parametric surfaces, are provided. Algorithms to compute these cones for a regular B6zier surface are provided. It is shown that a tangent cone can be computed from a hodograph, and a normal cone can be computed from a normal surface of a B6zier surface. It is also shown that a simple tra...

An area-oriented analytical visibility method for displaying parametrically defined tensor-product surfaces

An analytical method to determine the visible parts of parametrically defined tensor-product surfaces is described. All vistbility calculations are strictly oriented on the (u, u)-parameter plane. This leads to substantial advantages over visibility algorithms based on the approximation of curved surfaces by sets of planar polygons. The new algorithm allows the calculation and the display of bo...

Performance Evaluation of Detector Algorithms of Dust Storms in Arid Lands (Case Study: Yazd Province)

Introduction: In recent years, frequency and intensity of dust storms have been increased because of human destructive activities and caused significant loss in different aspects of hygienic and health, environmental and socio-economic sections. Therefore, detection and trace of dust storms in shortest time is the first effective step in preparation and implementation of strategic and operation...