CPLnonmanifold
by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - Auxiliary function
Introduced first in SolidGeometry 2.0, Creation date: 2014-12-06, Last change: 2025-09-14
true if a point is used twice in the CPL or PL
Description
Slow, try to avoid if possbile
Example Illustration
Syntax
nm=CPLnonmanifold(CPL)
Input Parameter
Output Parameter
nm: | | true if non manifold points |
Examples
CPLnonmanifold(CPLofPL(PLcircle(10)))
Copyright 2014-2025 Tim C. Lueth. All rights reserved. The code is the property of Tim C. Lueth and may not be redistributed or modified without explicit written permission. This software may be used free of charge for academic research and teaching purposes only. Commercial use, redistribution, modification, or reverse engineering is strictly prohibited. Access to source code is restricted and granted only under specific agreements. For licensing inquiries or commercial use, please contact: Tim C. Lueth
Algorithm (Workflow)
This algorithm checks if a closed polygon list (CPL) contains non-manifold points, meaning points that are used more than once in the list.
Input Parameters
- CPL: A closed polygon list, which is a list of points defining a closed shape.
Output Results
- nm: A boolean value that is true if there are non-manifold points in the CPL.
Algorithm Steps
- The function begins by ensuring that the CPL is ordered and any NaN values are correctly placed at the end of the list. This is done using the
CPLorder function.
- It identifies the indices of NaN values in the first column of the CPL and adjusts the list to ensure NaN values are at the end.
- All rows containing NaN values are removed from the CPL.
- The function then creates a unique list of points,
UPL, by removing duplicate rows from the CPL.
- Finally, it checks if the size of the original CPL is different from the size of the unique list
UPL. If they differ, it means there were duplicate points, and the function returns true, indicating non-manifold points.
Algorithm explaination created using ChatGPT on 2025-08-18 23:15. (Please note: No guarantee for the correctness of this explanation)
Last html export of this page out of FM database by TL: 2025-09-21