Vtk check if polydata objects intersect - c++

Question

I'm trying to bring 2 vtkPolyData objects closer to each other without them intersecting. I would like to "test" if one is inside the other with a simple boolean function. My first thought was to use vtkBooleanOperationPolyDataFilter with the datasets as inputs and calculate the intersection and then check if the resulting PolyData object was a NULL object. This however, does not give the desired result.
The code I'm currently using looks like this:
bool Main::Intersect(double *trans)
{
vtkSmartPointer<vtkPolyData> data1 = vtkSmartPointer<vtkPolyData>::New();
vtkSmartPointer<vtkPolyData> data2 = vtkSmartPointer<vtkPolyData>::New();
data1->ShallowCopy(this->ICPSource1);
data2->ShallowCopy(this->ICPSource2);
//This piece is just to reposition the data to the position I want to check
for (unsigned int k=0; k<3; k++)
{
trans[k]/=2;
}
translate(data2, trans);
for (unsigned int k=0; k<3; k++)
{
trans[k]*=-1;
}
translate(data1, trans);
//This is my use of the actual vtkBooleanOperationPolyDataFilter class
vtkSmartPointer<vtkBooleanOperationPolyDataFilter> booloperator = vtkSmartPointer<vtkBooleanOperationPolyDataFilter>::New();
booloperator->SetOperationToIntersection();
booloperator->AddInputData(data1);
booloperator->AddInputData(data2);
booloperator->Update();
if (booloperator->GetOutput()==NULL)
return 0;
else
return 1;
}
Any help regarding this issue is highly appreciated. Also, I don't know if the "vtkBooleanOperationPolyDataFilter" class is really the best one to use, it's just something I found and thought might work.
Thanks in advance,
Xentro
EDIT: I said this doesn't give the desired result but it does improve my result. It has some kind of influence on my movement criterion (which was the point) but in the end result the datasets still intersect sometimes.

Answer 1

You can call PolyDataObject->GetBounds() for both your objects and compare their values. This does only work, of course, if your objects intersect first at their boundaries. But for intersection of simple geometries this should provide a light-weight solution. See here for an example.
Regarding the vtkBooleanOperationPolyDataFilter I can only say that I tried to use it before, too, and it did not work at all how I wanted it to. In my searches I found many other people complaining about it.
EDIT: Did you try the vtkPolyDataIntersectionFilter? The class reference can be found here.
vtkIntersectionPolyDataFilter computes the intersection between two vtkPolyData objects. The first output is a set of lines that marks the intersection of the input vtkPolyData objects. The second and third outputs are the first and second input vtkPolyData, respectively. Optionally, the two output vtkPolyData can be split along the intersection lines.