# isGlobalSurfDirOutward

Below is a demonstration of the features of the `isGlobalSurfDirOutward` function

## Contents

```
clear; close all; clc;
```

## Syntax

`[L]=isGlobalSurfDirOutward(F,V);`

## Description

This function returns a boolean denoting wether surface normals are pointing outward (1) (which would result in a positive volume being computed) or inward (2) (which would result in a negative volume being computed). The method assumes that the normal directions are coherent across the surface.

## Examples

Example surface

[F,V]=stanford_bunny;

Computing a logic denoting whether the normals point outward or inwards. For the example surface the normals point outward, so the logical should return a true

```
% This one should be true
[L]=isGlobalSurfDirOutward(F,V)
```

L = logical 1

However inverting the surface causes the normal directions to point inward, hence a false is returned.

```
% Reversed should be false
[L]=isGlobalSurfDirOutward(fliplr(F),V)
```

L = logical 0

```
cFigure;
gpatch(F,V);
patchNormPlot(F,V);
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) 2006-2023 Kevin Mattheus Moerman and the GIBBON contributors

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