3D breakline extraction from point clouds with the Medial Axis Transform

Master thesis (2019)

Authors

Q. Wang Architecture and the Built Environment

Contributors

R.Y. Peters Urban Data Science - Architecture and the Built Environment (supervisor 1)
H. Ledoux Urban Data Science - Architecture and the Built Environment (supervisor 2)
Faculty
Architecture and the Built Environment
Copyright: © 2019 Qu Wang
Point cloud Medial Axis Transform Mountain Breakline
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Published Date

09-06-2019

Language

English

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Faculty

Architecture and the Built Environment

Abstract

This project develop a new method to generate breakline from the point cloud directly with the MAT. The breakline is a structured line of the object surface which has high curvature. Meanwhile, the reciprocal of the medial edge ball's radius can represent the point with high curvature, which is the fundamental idea of this project. The key parts of the method are: (a) with the help of MAT detecting candidate points having high curvature; (b) connect the candidate points to get breaklines with graph theory or polynomial fitting. The topology of the breakline is considered. In addition, this project also provides the polyline simplification and smoothing. In the resulting breakline, 27/32 are true positive. In general, the average correctness is 97% and 96%, the average quality is 90.67% and 91.19%, and the average completeness is 93.84% and 93.92% for valley and ridge. Most of accuracy parameters are above 80%. The accuracy is high. As to the precision, the average polyline precision is 0.3 and 0.23, and the average vertex precision is 1.14 meter and 1.12 meter. Comparing with the point density 2 pts/m^2. 25 of 27 breaklines' polyline precision is better than 0.5. 16 of 27 breakline's vertex precision is better than 1.0; and 23 of 26 is better than 1.5. The precision is also good. The source code is on Github: https://github.com/qq2012/geoflow-nodes.