# regionTriMeshRand2D

Below is a basic demonstration of the features of the regionTriRandMesh2D function.

## Contents

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

## SIMULATING BOUNDARY CURVES

```%Boundary 1
ns=150;
t=linspace(0,2*pi,ns);
t=t(1:end-1);
r=6+2.*sin(5*t);
[x,y] = pol2cart(t,r);
V1=[x(:) y(:)];

%Boundary 2
[x,y] = pol2cart(t,ones(size(t)));
V2=[x(:) y(:)+4];

%Boundary 3
[x,y] = pol2cart(t,2*ones(size(t)));
V3=[x(:) y(:)-0.5];
```

## CREATING A REGION MESH

The input variable regionCell is a cell array containing all the boundary curves, e.g. for a two curve region 1 we would have something like regionSpec{1}={V1,V2} where V1 and V2 are the boundary curves. Multiple curves may be given here. The first curve should form the outer boundary of the entire region, the curves that follow should define holes inside this boundary and the space inside them is therefore not meshed. All the above is similar to the regionTriMesh2D function. Additional inputs can be provided here such as SD which is the X and Y standard deviation for random point offsets following seeding of points. Hence a semi-random point spacing and triangulation is obtained. The mesh is still smoothened though which gives points their final locations.

```%Defining a region
regionCell={V1,V2,V3}; %A region between V1 and V2 (V2 forms a hole inside V1)

plotOn=1; %This turns on/off plotting

%Desired point spacing
pointSpacing=0.5;
resampleCurveOpt=1;
SD=[0.2 0.2];
[F,V,C,DT]=regionTriMeshRand2D(regionCell,pointSpacing,SD,resampleCurveOpt,plotOn);

plotV(V1,'b-','LineWidth',2);
plotV(V2,'b-','LineWidth',2);
plotV(V3,'b-','LineWidth',2);
axis tight;
```

GIBBON www.gibboncode.org

Kevin Mattheus Moerman, [email protected]

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

Copyright (C) 2019 Kevin Mattheus Moerman

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