Abstract
To design and implement a system of simulating the process of charging and discharging awkward length cargo with computer, key task is to construct high precision three-dimensional model of the hull. In view of problems exiting in distance subdivision method, we proposed one adaptive subdivision method for NURBS (Non-Uniform Rational B-Splines) curve based on energy function. In view of problems from repeated storage of coordinate points and non-linear search of adjacent field in tree structure, namely, when applying binary-tree and quad-tree to recursively divide surface, the intermediate result from each division needs to be saved, each vertex coordinate is repeatedly saved 3 to 4 times, we proposed quadrangle coding method produced automatically by triangle grid of ship hull based on NURBS. Simulation results show that this algorithm has obviously saved time and space, improved the algorithm efficiency, avoided crack between the grids and proved good application in shipping industries.
Highlights
Development of NURBS began in the 1950s by engineers who were in need of a mathematically precise representation of freeform surfaces like those used for ship hulls, aerospace exterior surfaces, and car bodies, which could be exactly reproduced whenever technically needed
Ship hull NURBS surface can be triangulated on the premise of surface subdivision
Aiming at solving problems in simulation of 3D ship hull and display of real image, this paper put forward an innovative arithmetic for adaptive triangular mesh generation of ship hull surface based on NURBS by applying NURBS curve and surface theory
Summary
Development of NURBS began in the 1950s by engineers who were in need of a mathematically precise representation of freeform surfaces like those used for ship hulls, aerospace exterior surfaces, and car bodies, which could be exactly reproduced whenever technically needed. Reflection method is to adopt planar mesh generation method in parameter field to complete subdivision, and reflect mesh nodes in parameter field to real space maintaining connection relationships of mesh nodes to obtain triangulation of the surface. This method is a little aside from the approaching precision with the original surface, which cannot guarantee space form of the generated meshes. The original surface is divided into small surface recursively based on surface curvature until precision requirements of surface pieces are satisfied These quadrilateral meshes are transformed into triangular meshes directly. Cut corner arithmetic is applied to create crack prevention triangle grids
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
