ELofFL
by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - Auxiliary function
Introduced first in SolidGeometry 1.0, Creation date: 2012-07-29, Last change: 2025-09-14
converts a facet list into an edge list (simple)
Description
returns the edge list in facet order
if the facet list is not n x 3 but n x m use ELofFLpatch
See Also: ELofFLborder
, ELofFLpatch
, ELunique
Example Illustration
Syntax
EL=ELofFL(FL)
Input Parameter
Output Parameter
Examples
Show the edges of a VLFL-solid
[VL,FL]=VLFLbox (10,20,30);
EL=ELofFL (FL);
SGfigure; view(-30,30); VLELplot (VL,EL);
Copyright 2012-2025 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 converts a facet list (FL) into an edge list (EL). It is designed to work with a facet list that is structured as an n x 3 matrix, where each row represents a triangular facet defined by three vertices.
Input Parameters
- FL: A facet list represented as an n x 3 matrix. Each row contains three integers, each representing a vertex index of a triangular facet.
Output Results
- EL: An edge list represented as an n x 2 matrix. Each row contains two integers, each representing a vertex index of an edge.
Algorithm Steps
- Extract the first, second, and third columns of the facet list (FL) to represent the vertices of each triangular facet.
- Construct the edge list (EL) by concatenating the following edges for each facet:
- Edge from the first vertex to the second vertex.
- Edge from the second vertex to the third vertex.
- Edge from the third vertex back to the first vertex.
- Reshape the concatenated edge list to ensure it is structured as an n x 2 matrix, where each row represents an edge.
- If no output argument is specified (nargout == 0), plot the edge list using the SGfigure and ELplot functions.
Example Usage
To demonstrate the use of this function, consider the following example:
[VL,FL] = VLFLbox(10,20,30);
EL = ELofFL(FL);
SGfigure; view(-30,30); VLELplot(VL,EL);
This example creates a box with specified dimensions, converts its facet list to an edge list, and then plots the edges.
Algorithm explaination created using ChatGPT on 2025-08-18 23:53. (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