Partition local fairing weight factor-based T-spline curved-surface fitting method

A spline surface and fairing weight technology, applied in image data processing, 3D modeling, instruments, etc., can solve problems such as low precision, difficulty in satisfying different areas at the same time, affecting calculation efficiency, etc., and achieve the effect of improving quality

Active Publication Date: 2017-07-25
ZHEJIANG UNIV
View PDF4 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method can adjust the weight of fairing and precision in the fitting calculation through the global fairing weight, in some cases, some areas of a surface may have low accuracy, while other areas are smooth poor sex situation
At this time, it is difficult for this method to meet the needs of different regions at the same time
On the other hand, in order to ensure the reliability of the results, the method of evenly arranging the fairness checkpoints needs to add a large number of smoothness check

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Partition local fairing weight factor-based T-spline curved-surface fitting method
  • Partition local fairing weight factor-based T-spline curved-surface fitting method
  • Partition local fairing weight factor-based T-spline curved-surface fitting method

Examples

Experimental program
Comparison scheme
Effect test

specific Embodiment approach

[0080] Construct the fitting equation of each triangular mesh vertex, construct the smoothness equation of each smoothness inspection point according to the local smoothness weight and the global smoothness weight of each smoothness inspection point, and form a hyperparameter about the control point coordinates Determining the system of equations, using the least squares method to solve the overdetermined system of equations about the coordinates of the control points, to obtain the fitting coordinates of the surface control points, the specific implementation is as follows:

[0081] For the tth triangular mesh vertex, its coordinates are marked as Q t =[x t ,y t ,z t ], the coordinates of the parameter field are marked as [u t ,v t ], the fitting equation can be constructed:

[0082]

[0083] where P k is the Euclidean space coordinate of the kth control point, R k (u,v) is the rational mixed basis function corresponding to the control point, and its analytical expr...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The present invention discloses a partition local fairing weight factor-based T-spline curved-surface fitting method. The method comprises the following steps of inputting a parameterized triangular grid and an initial T-spline; segmenting the region of a parameter domain to obtain a plurality of sub-regions of the parameter domain; according to the topological structure of the original image of the control grid of the input T-spline on the parameter domain, generating a fairness inspection point set; according to the density weight of each fairness inspection point and the local fairness weight factor of the sub-region of the above fairness inspection point, calculating the local fairness weight of each fairness inspection point; according to the fitting error of each vertex of the triangular grid and a curved-surface fairness energy column equation set, conducting the least square solution method to obtain a final T-spline curved-surface fitting result. According to the invention, fairness inspection points are adaptively generated according to the complexity of a control grid. Meanwhile, the fairness and the accuracy of different regions are coordinated through partition and local fairness weights. Therefore, the quality of a fitting surface is improved and the calculation efficiency is increased.

Description

technical field [0001] The invention relates to the field of spline surface fitting methods, in particular to a T-spline surface fitting method based on partition local fairing weight factors. Background technique [0002] Spline surface technology is one of the core technologies in the CAD / CAM field, which describes the geometric shape of the model in the form of polynomial parametric surfaces. T-spline technology is an advanced spline surface modeling technology proposed in recent years. It is suitable for expressing complex geometric shapes with a single surface, so it has received extensive attention from the academic community. T-spline surface modeling technology is one of the cores of T-spline technology research, and T-spline surface fitting technology is the most basic link. Improving the efficiency and effect of surface fitting method is the key to improving spline surface modeling technology. One of the keys. [0003] The T-spline surface fitting method usually ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G06T17/30G06T17/00
CPCG06T17/005G06T17/30
Inventor 傅建中商策林志伟冯嘉炜
Owner ZHEJIANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap