[vtkusers] Re: vtkWarpTo

[Amy Henderson]

Hi Marisa,

The points in VTK have an associated point id.  You can get the points for 
your data set by calling
mypoly->GetPoints();.  You can also get the coordinates of each point, and 
you can use this information to determine the point ids of the points you 
want to warp.  (See the online man page for vtkPoints for more details: 
http://www.vtk.org/doc/nightly/html/classvtkPoints.html)

You can create an instance of vtkFloatArray to contain a normal vector per 
point.  (The ids of the points and the ids of the normals should 
match.)  Once you've filled in this array, you can call 
mypoly->GetPointData()->SetNormals(normals);.

- Amy

PS  Please keep this type of discussion on the vtkusers list so everyone 
benefits from the discussion (and there are more people to help answer your 
question).

At 04:20 PM 3/18/2003 +0000, you wrote:
>Hi Amy
>Thanks for you help. But I still don't know how to do it.
>When you say "... you already have to specify a vector per point in
>your input data." what do you meen??? How do I do that???
>My code is like this:
>
>int main( int argc, char *argv[] )
>{
>  vtkSuperquadricSource *Superquadric = vtkSuperquadricSource::New();
>        Superquadric->SetThetaResolution( 100.0 );
>         Superquadric->SetPhiResolution( 100.0 );
>         Superquadric->SetPhiRoundness( 1 );
>         Superquadric->SetThetaRoundness(1);
>         Superquadric->SetScale(0.65,1,0.65);
>
>  vtkPolyData *mypoly = Superquadric->GetOutput();
>  Superquadric->Update();
>
>  vtkWarpVector *warp = vtkWarpVector::New();
>         warp->SetInput(mypoly);
>         warp->SetScaleFactor(0.2);
>
>  vtkPolyDataMapper *ClipMapper = vtkPolyDataMapper::New();
>         ClipMapper->SetInput(warp->GetPolyDataOutput());
>
>  vtkActor *SuperquadricActor = vtkActor::New();
>         SuperquadricActor->SetMapper( ClipMapper );
>
>  vtkRenderer *ren1= vtkRenderer::New();
>         ren1->AddActor( SuperquadricActor );
>         ren1->SetBackground( 0.1, 0.2, 0.4 );
>
>  vtkRenderWindow *renWin = vtkRenderWindow::New();
>         renWin->AddRenderer( ren1 );
>         renWin->SetSize( 1024, 960 );
>
>  vtkRenderWindowInteractor* iren = vtkRenderWindowInteractor::New();
>         iren->SetRenderWindow(renWin);
>         iren->Initialize();
>         iren->Start();
>  int i;
>  for (i = 0; i < 3060; ++i)
>  {
>         // render the image
>         renWin->Render();
>  }
>
>  SuperquadricActor->Delete();
>  renWin->Delete();
>  return 0;
>}
>
>And also, how do I specify the points where I want to use a 'null' 
>vector?? How do I say that in that point I want to user that vector?? How 
>do I specify each point???
>Thanks for your help...
>Marisa
>
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