VTK/Tutorials/VtkIdType

Confused why you can't use ints or unsigned ints in some places?

Here is an example:

vtkSmartPointer<vtkCellArray> vertices = vtkSmartPointer<vtkCellArray>::New();
 
for ( unsigned int i = 0; i < polydata->GetNumberOfPoints(); ++i )
  { 
  vertices->InsertNextCell(1,i);
  }

The error generated is:

error: invalid conversion from 'unsigned int' to 'const vtkIdType*'

To fix this, you need to put the value into a vtkIdType object, as follows:

vtkSmartPointer<vtkCellArray> vertices = vtkSmartPointer<vtkCellArray>::New();
 
for ( unsigned int i = 0; i < polydata->GetNumberOfPoints(); ++i )
  { 
  vtkIdType id[1];
  id[0] = i;
  vertices->InsertNextCell(1,id);
  }