Hull surface reconstruction method based on non-uniform rational B-spline surface interpolations

Abstract

The invention relates to the technical field of hull design and particularly discloses a hull surface reconstruction method based on non-uniform rational B-spline surface interpolations. The method comprises the steps of adopting characteristic lines to divide a hull wire-frame model into surface piece grids; conducting homogenization treatment on the surface piece grids to obtain position coordinates of offset points, adding tangent vector characteristics to the offset points and generating non-uniform rational B-spline grids; interpolating B-spline surfaces with multiple nodes into the non-uniform rational B-spline grids to obtain multiple non-uniform rational B-spline surface pieces, and splicing the surface pieces along the characteristic lines among the surface pieces so as to obtain a gapless non-uniform rational B-spline surface and achieve continuous G1 or G0 (knuckle line) on the characteristic lines. Fewer surface pieces (several or dozens of pieces) can be utilized to reconstruct a complicated hull surface and generate the gapless NURBS surface so as to achieve the smooth hull surface effect, and hull surface modification can be facilitated.

Description

technical field [0001] The invention relates to the technical field of hull design, in particular to a hull surface reconstruction method based on non-uniform rational B-spline surface interpolation. Background technique [0002] At present, the methods for reconstructing the hull surface mainly include Coons surface, skin surface and interpolation surface method. [0003] The Coons surface method adopts the superlimit interpolation method to construct a surface that satisfies the given boundary and cross-boundary tangent vector conditions, so that the constructed surface patches can be smoothly merged. The method is simple, easy to implement, and adaptable to various types of ships. However, in order to obtain a relatively smooth hull surface, the wireframe model must be carefully processed and smoothed, and there are too many surface patches (tens to hundreds of pieces), and there will be gaps between the surface patches. Interactively modifying the hull and generating a...

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Problems solved by technology

However, this method generates too many surface patches (tens to hundreds of pieces), and there will be gaps between the surface patches

For ship design, it is often necessary to modify the surface of the hull to meet the design requirements. Obviously, too many surface pieces make interactive modification difficult and the workload is heavy

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