VLFLfreeboundaryfacets
by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - Surfaces
Introduced first in SolidGeometry 4.1, Creation date: 2017-08-14, Last change: 2025-09-14
returns the facets attached to the freeboundary edges
Description
During testing of SGbool it became obvious, that the result of SGbool without a postprocessing will create structures that MATLAB's triangulation procedure will consider as open edge structure while Meshlab would consider it as perfect solid.
Those tests where performed using
1. A 1e-12 grid on both solids!
2. Non rounding during SGintersectFacetPoints
3. Thresholds of 1e-6 for VL and 1e-9 for NPLs
4. Thresholds for 1e-6 for UVP and added triangulation points
5. Thresholds of 1e-6 for minimal area of a facet (line type)
Even than, there are problems with surface that come from the function SGisinterior, since there is a bug for coordinates ontop of barycentric coordinates
A final fusion of 1e-8 on the point position solves this problem.
Therefore Meshlab roundes at least at 1e-8 / and the accuracy of SGbool is maximum 1e-8;
See Also: VLFLplotfreeboundary
Example Illustration
Syntax
[FLb,EL,FLx,fbf]=VLFLfreeboundaryfacets(VL,FL,[thr])
Input Parameter
VL: | | Vertex list |
FL: | | Facet list |
thr: | | threshold for VLFLshort2; default is 0; |
Output Parameter
FLb: | | facets attached to the freeboundary edges |
EL: | | freeboundary edges |
FLx: | | Faces not attached to boundary edges |
fbf: | | face index of Flb |
Examples
A=SGbox; A.FL=A.FL([1:3, 5:end],:); VLFLfreeboundaryfacets(A.VL,A.FL);
Copyright 2017-2025 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
Last html export of this page out of FM database by TL: 2025-09-21