[vtkusers] Re: mesh intersecting algorithms

[Goodwin Lawlor]

Leila Baghdadi wrote:
> Hi everyone,
> 
> I am just wondering is there any algorithms implemented in vtk which
> determine the intersecting points between meshes.
> 
> 
> Thanks
> 
> Leila

Hi Leila,

Sounds like this filter would do the job (have a look at the right 
figure). 
http://www.bioengineering-research.com/vtk/vtkCollisionDetectionFilter.htm

 From TestCollisionDetection1.cxx you can get the (poly)line of 
intersection with:

    vtkCollisionDetectionFilter *collide = 
vtkCollisionDetectionFilter::New();
    collide->SetInputConnection(0, sphere0->GetOutputPort());
    collide->SetMatrix(0, matrix0);
    collide->SetInputConnection(1, sphere1->GetOutputPort());
    collide->SetMatrix(1, matrix1);
    collide->SetBoxTolerance(0.0);
    collide->SetCellTolerance(0.0);
    collide->SetNumberOfCellsPerBucket(2);
    collide->SetCollisionModeToAllContacts();
    collide->GenerateScalarsOn();

    vtkCleanPolyData *clean = vtkCleanPolyData::New();
      clean->SetInputConnection(collide->GetContactsOutputPort());

    vtkStripper *stripper = vtkStripper::New();
      stripper->SetInputConnection(clean->GetOutputPort());
      stripper->Update();

Have a look at the full code of the test if you want to clip the meshes...

hth

Goodwin