patchNormal

Below is a demonstration of the features of the patchNormal function

Contents

clear; close all; clc;

Syntax

[N,Vn,Nv]=patchNormal(F,V);

Description

Compute the surface normals N for the input path data defined by the faces F and vertices V. Optional additional outputs include the face centres Vn or the vertex normals Nv.

Examples

testCase=2;
switch testCase
    case 1 %Single element square 1x1
        z=2;
        V=[0 0 0; 1 0 0; 0 1 z; 1 1 0];
        F=[1 2 4 3];
    case 2 %Sphere triangles
        r=1;
        n=2;
        [F,V]=geoSphere(n,r);
end

[N,P,NV]=patchNormal(F,V);

Visualization

s=mean(patchEdgeLengths(F,V));

cFigure;
subplot(1,2,1);
title('Face normals')
gpatch(F,V,'bw');
quiverVec(P,N,s,'k')
axisGeom; camlight headlight;

subplot(1,2,2);
title('Vertex normals')
gpatch(F,V,'bw');
quiverVec(V,NV,s,'k')
axisGeom; camlight headlight;

drawnow;

GIBBON www.gibboncode.org

Kevin Mattheus Moerman, [email protected]

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License: https://github.com/gibbonCode/GIBBON/blob/master/LICENSE

GIBBON: The Geometry and Image-based Bioengineering add-On. A toolbox for image segmentation, image-based modeling, meshing, and finite element analysis.

Copyright (C) 2006-2021 Kevin Mattheus Moerman and the GIBBON contributors

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

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Published with MATLAB® R2021a