# vtkDelaunay2D
**URL:** https://discourse.vtk.org/t/vtkdelaunay2d/11447
**Category:** Support
**Created:** [May 13, 2023, 6:54am UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447 "2023-05-13T06:54:44Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@Frankenstein](https://discourse.vtk.org/u/Frankenstein)
#### Post date: [May 13, 2023, 6:54am UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/1 "2023-05-13T06:54:44Z")
I have created a surface using the vtkDelaunay2D class, but due to different data, it often causes surface distortion
like this ,How should I make these surfaces smoother? By the way, I have used several smoothing functions included in vtk, but the results are not ideal,Thank you for your suggestion
---
### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [May 14, 2023, 12:38pm UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/2 "2023-05-14T12:38:11Z")
Hello,
To smooth out such artifacts, you can refine the mesh while interpolating the finer triangles. You can try either `vtkLinearSubdivisionFilter` or `vtkButterflySubdivisionFilter` classes.
[https://vtk.org/doc/nightly/html/classvtkLinearSubdivisionFilter.html](https://vtk.org/doc/nightly/html/classvtkLinearSubdivisionFilter.html)
[https://vtk.org/doc/nightly/html/classvtkButterflySubdivisionFilter.html](https://vtk.org/doc/nightly/html/classvtkButterflySubdivisionFilter.html)
take care,
PC
---
### Author:  [@Frankenstein](https://discourse.vtk.org/u/Frankenstein)
#### Post date: [May 16, 2023, 7:24am UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/3 "2023-05-16T07:24:31Z")
Actually, this picture I haved used class vtkLinearSubdivisionFilter to create it, tried class vtkButterflySubdivisionFilter, too，But it didn’t work. Thanks for the advice anyway，If you have any better suggestions, I’d appreciate it
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### Author:  [@Charles\_Gueunet](https://discourse.vtk.org/u/Charles_Gueunet)
#### Post date: [May 16, 2023, 7:29am UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/4 "2023-05-16T07:29:28Z")
Dear @Frankenstein ,
If you can deal with the CGAL’s GPLv3 license, I would recommand you to have a look at the [vespa project](https://gitlab.kitware.com/vtk-cgal/vespa).
As presented in [this blog](https://www.kitware.com/vespa-advanced-mesh-processing-based-on-cgal-for-vtk-and-paraview/), this VTK module (and ParaView plugin) expose CGAL smoothing methods, as well as isotropic remeshing, alpha wrapping, boolean operations …
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### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [May 16, 2023, 1:59pm UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/5 "2023-05-16T13:59:51Z")
> [@Frankenstein](#):
>
> But it didn’t work.
Don’t give up so early. Those algorithms have lots of parameters. Have you tried them all?
---
### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [May 16, 2023, 2:00pm UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/6 "2023-05-16T14:00:52Z")
> [@Frankenstein](#):
>
> If you have any better suggestions
No, I haven’t. Why don’t you post the code you used before dismissing the algorithms?
---
### Author:  [@Frankenstein](https://discourse.vtk.org/u/Frankenstein)
#### Post date: [May 18, 2023, 8:06am UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/7 "2023-05-18T08:06:53Z")
My Bad. Here’s my code
#ifndef INITIAL\_OPENGL
#define INITIAL\_OPENGL
#include \
VTK\_MODULE\_INIT(vtkRenderingOpenGL2)
VTK\_MODULE\_INIT(vtkRenderingVolumeOpenGL2)
VTK\_MODULE\_INIT(vtkInteractionStyle)
VTK\_MODULE\_INIT(vtkRenderingFreeType)
#endif
#include
#define pi 3.1415926535
#include \
#include \
#include \
#include \
#include \
#include \
#include \
#include
#include \
#include \
#include \
#include \
#include \
#include \
#include \
#include \
#include \
#include \
#include \
#include \
#include \
int main() {
```
std::ifstream ifs_p1;
ifs_p1.open("C:/Users/15409/Desktop/ver1/result_p1.txt");
std::vector>pp1;
std::vector pp1_tmp;
double tmp;
for(int i=0;i<72+1;i++)
{
for(int j=0;j<36+1;j++)
{
ifs_p1>>tmp;
pp1_tmp.push_back(tmp);
}
pp1.push_back(pp1_tmp);
pp1_tmp.clear();
}
std::vector>XX,XX1;
std::vector X;
std::vector>YY,YY1;
std::vector Y;
std::vector>ZZ;
std::vector Z;
double wzj=150;double r=40;
int m=73;int n=37;double B=32;
```
for(int i=0;i\<37;i++)
{
for(int j=0;j\<73;j++)
{
X.push\_back(cos(((180-wzj)/2+180+wzj\*j/(m-1))_pi/180)_(r+pp1[j][i]_500));
Y.push\_back(sin(((180-wzj)/2+180+wzj_j/(m-1))_pi/180)_(r+pp1[j][i]_500));
Z.push\_back(i_B/(n-1)-(B/2));
}
XX.push\_back(X);
YY.push\_back(Y);
ZZ.push\_back(Z);
Z.clear();
X.clear();
Y.clear();
}
```
vtkSmartPointer pts =vtkSmartPointer::New();
for(int i=0;i<37;i++)
{
for(int j=0;j<73;j++)
{
pts->InsertNextPoint(ZZ[i][j],XX[i][j],YY[i][j]);
}
}
for(int i=0;i<37;i++)
{
for(int j=0 ;j<73;j++)
{
X.push_back(i);
Y.push_back(j);
}
XX1.push_back(X);
YY1.push_back(Y);
X.clear();
Y.clear();
}
vtkSmartPointer pts_surf =vtkSmartPointer::New();
for(int i=0;i<37;i++)
{
for(int j=0;j<73;j++)
{
pts_surf->InsertNextPoint(XX1[i][j],YY1[i][j],pp1[j][i]*500);
}
}
vtkSmartPointer poly_surf = vtkSmartPointer::New();
poly_surf->SetPoints(pts_surf);
vtkSmartPointerDelaunay_surf =vtkSmartPointer::New();
Delaunay_surf->SetInputData(poly_surf);
Delaunay_surf->Update();
vtkSmartPointer subdiv_surf = vtkSmartPointer::New();
subdiv_surf->SetInputConnection(Delaunay_surf->GetOutputPort());
subdiv_surf->SetNumberOfSubdivisions(3);
subdiv_surf->Update();
vtkSmartPointer mapper_surf = vtkSmartPointer::New();
mapper_surf->SetInputConnection(Delaunay_surf ->GetOutputPort());
vtkSmartPointer actor_surf = vtkSmartPointer::New();
actor_surf->SetMapper(mapper_surf);
vtkSmartPointer poly = vtkSmartPointer::New();
poly->SetPoints(pts);
vtkSmartPointerDelaunay =vtkSmartPointer::New();
Delaunay->SetInputData(poly);
Delaunay->Update();
vtkSmartPointer subdiv = vtkSmartPointer::New();
subdiv->SetInputConnection(Delaunay->GetOutputPort());
subdiv->SetNumberOfSubdivisions(3);
subdiv->Update();
vtkSmartPointer mapper = vtkSmartPointer::New();
mapper->SetInputConnection(subdiv ->GetOutputPort());
vtkSmartPointer actor = vtkSmartPointer::New();
actor->SetMapper(mapper);
vtkSmartPointer leftRenderer = vtkSmartPointer::New();
vtkSmartPointer rightRenderer = vtkSmartPointer::New();
leftRenderer->AddActor(actor);
leftRenderer->SetBackground(0.53, 0.64, 0.89);
leftRenderer->SetViewport(0, 0, 0.5, 1.0);
rightRenderer->AddActor(actor_surf);
rightRenderer->SetViewport(0.5, 0, 1.0, 1.0);
vtkSmartPointer window = vtkSmartPointer::New();
window->AddRenderer(leftRenderer);
window->AddRenderer(rightRenderer);
window->SetSize(640, 480);
vtkSmartPointer interactor = vtkSmartPointer::New();
interactor->SetRenderWindow(window);
interactor->Initialize();
interactor->Start();
return 0;
```
}
the result is here
---
### Author:  [@Frankenstein](https://discourse.vtk.org/u/Frankenstein)
#### Post date: [May 18, 2023, 8:10am UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/8 "2023-05-18T08:10:00Z")
I already know that I can control the parameter input here to improve the smoothness of the surface, but it takes too much time. Maybe I should change the computer
---
### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [July 20, 2023, 2:08pm UTC](https://discourse.vtk.org/t/vtkdelaunay2d/11447/9 "2023-07-20T14:08:33Z")
> [@Frankenstein](#):
>
> the result is here
> 
Well, looks like the output if fine for me. I assume the second image is what you need.
regards,
PC