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| ==ConvertToVTK.cxx==
| | {{warning|1=The media wiki content on this page is no longer maintained. The examples presented on the https://itk.org/Wiki/* pages likely require ITK version 4.13 or earlier releases. In many cases, the examples on this page no longer conform to the best practices for modern ITK versions.}} |
| <source lang="cpp">
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| // ITK
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| #include "itkLineCell.h"
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| #include "itkMesh.h"
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| #include "itkTriangleCell.h"
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| #include "itkQuadrilateralCell.h"
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| | |
| // VTK
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| #include <vtkCellArray.h>
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| #include <vtkSmartPointer.h>
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| #include <vtkUnstructuredGrid.h>
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| #include <vtkXMLUnstructuredGridWriter.h>
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| | |
| typedef itk::Mesh< float, 3 > MeshType;
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| | |
| // Functions
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| static MeshType::Pointer CreateMeshWithEdges();
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| static void ConvertMeshToUnstructuredGrid(MeshType::Pointer, vtkUnstructuredGrid*);
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| | |
| | |
| class VistVTKCellsClass
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| {
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| vtkCellArray* m_Cells;
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| int* m_LastCell;
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| int* m_TypeArray;
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| public:
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| // typedef the itk cells we are interested in
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| typedef itk::CellInterface<
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| MeshType::PixelType,
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| MeshType::CellTraits > CellInterfaceType;
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| | |
| typedef itk::TriangleCell<CellInterfaceType> floatTriangleCell;
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| typedef itk::QuadrilateralCell<CellInterfaceType> floatQuadrilateralCell;
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| | |
| // Set the vtkCellArray that will be constructed
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| void SetCellArray(vtkCellArray* a)
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| {
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| m_Cells = a;
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| }
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| // Set the cell counter pointer
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| void SetCellCounter(int* i)
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| {
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| m_LastCell = i;
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| }
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| // Set the type array for storing the vtk cell types
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| void SetTypeArray(int* i)
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| {
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| m_TypeArray = i;
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| }
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| // Visit a triangle and create the VTK_TRIANGLE cell
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| void Visit(unsigned long, floatTriangleCell* t)
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| {
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| m_Cells->InsertNextCell(3, (vtkIdType*)t->PointIdsBegin());
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| m_TypeArray[*m_LastCell] = VTK_TRIANGLE;
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| (*m_LastCell)++;
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| }
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| // Visit a triangle and create the VTK_QUAD cell
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| void Visit(unsigned long, floatQuadrilateralCell* t)
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| {
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| m_Cells->InsertNextCell(4, (vtkIdType*)t->PointIdsBegin());
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| m_TypeArray[*m_LastCell] = VTK_QUAD;
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| (*m_LastCell)++;
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| }
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| };
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| | |
| | |
| int main(int, char *[])
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| {
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| MeshType::Pointer mesh = CreateMeshWithEdges();
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|
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| vtkSmartPointer<vtkUnstructuredGrid> unstructuredGrid = vtkSmartPointer<vtkUnstructuredGrid>::New();
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| ConvertMeshToUnstructuredGrid(mesh, unstructuredGrid);
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| | |
| // Write file
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| vtkSmartPointer<vtkXMLUnstructuredGridWriter> writer =
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| vtkSmartPointer<vtkXMLUnstructuredGridWriter>::New();
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| writer->SetFileName("output.vtu");
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| writer->SetInputConnection(unstructuredGrid->GetProducerPort());
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| writer->Write();
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| | |
| return EXIT_SUCCESS;
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| }
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| | |
| | |
| | |
| MeshType::Pointer CreateMeshWithEdges()
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| {
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| | |
| MeshType::Pointer mesh = MeshType::New();
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| | |
| // Create points
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| MeshType::PointType p0,p1,p2,p3;
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| | |
| p0[0]= -1.0; p0[1]= -1.0; p0[2]= 0.0; // first point ( -1, -1, 0 )
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| p1[0]= 1.0; p1[1]= -1.0; p1[2]= 0.0; // second point ( 1, -1, 0 )
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| p2[0]= 1.0; p2[1]= 1.0; p2[2]= 0.0; // third point ( 1, 1, 0 )
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| p3[0]= 1.0; p3[1]= 1.0; p3[2]= 1.0; // third point ( 1, 1, 1 )
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| | |
| mesh->SetPoint( 0, p0 );
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| mesh->SetPoint( 1, p1 );
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| mesh->SetPoint( 2, p2 );
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| mesh->SetPoint( 3, p3 );
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| | |
| std::cout << "Points = " << mesh->GetNumberOfPoints() << std::endl;
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| | |
| //access points
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| typedef MeshType::PointsContainer::Iterator PointsIterator;
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| | |
| PointsIterator pointIterator = mesh->GetPoints()->Begin();
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| | |
| PointsIterator end = mesh->GetPoints()->End();
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| while( pointIterator != end )
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| {
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| MeshType::PointType p = pointIterator.Value(); // access the point
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| std::cout << p << std::endl; // print the point
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| ++pointIterator; // advance to next point
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| }
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| | |
| typedef MeshType::CellType::CellAutoPointer CellAutoPointer;
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| typedef itk::LineCell< MeshType::CellType > LineType;
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| | |
|
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| CellAutoPointer line0;
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| line0.TakeOwnership( new LineType );
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| line0->SetPointId(0, 0); // line between points 0 and 1
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| line0->SetPointId(1, 1);
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| mesh->SetCell( 0, line0);
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| | |
| CellAutoPointer line1;
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| line1.TakeOwnership( new LineType );
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| line1->SetPointId(0, 1); // line between points 1 and 2
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| line1->SetPointId(1, 2);
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| mesh->SetCell( 1, line1);
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| | |
| CellAutoPointer line2;
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| line2.TakeOwnership( new LineType );
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| line2->SetPointId(0, 2); // line between points 2 and 3
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| line2->SetPointId(1, 3);
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| mesh->SetCell( 2, line2);
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|
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| /*
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| typedef MeshType::CellsContainer::Iterator CellIterator;
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| CellIterator cellIterator = mesh->GetCells()->Begin();
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| CellIterator CellsEnd = mesh->GetCells()->End();
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| | |
| while( cellIterator != CellsEnd )
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| {
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| MeshType::CellType * cellptr = cellIterator.Value();
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| LineType * line = dynamic_cast<LineType *>( cellptr );
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| | |
| long unsigned int* linePoint0 = line->PointIdsBegin();
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| //long unsigned int* linePoint1 = line->PointIdsEnd();
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| long unsigned int* linePoint1 = linePoint0+1;
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| std::cout << "line first point id: " << *linePoint0 << std::endl;
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| std::cout << "line second point id: " << *linePoint1 << std::endl;
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| | |
| ++cellIterator;
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| }
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| */ | |
| return mesh;
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| }
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| | |
| void ConvertMeshToUnstructuredGrid(MeshType::Pointer mesh, vtkUnstructuredGrid* unstructuredGrid)
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| {
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| // Get the number of points in the mesh
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| int numPoints = mesh->GetNumberOfPoints();
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| if(numPoints == 0)
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| {
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| mesh->Print(std::cerr);
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| std::cerr << "no points in Grid " << std::endl;
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| exit(-1);
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| }
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| | |
| // Create the vtkPoints object and set the number of points
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| vtkPoints* vpoints = vtkPoints::New();
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| vpoints->SetNumberOfPoints(numPoints);
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| // iterate over all the points in the itk mesh filling in
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| // the vtkPoints object as we go
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| MeshType::PointsContainer::Pointer points = mesh->GetPoints();
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| for(MeshType::PointsContainer::Iterator i = points->Begin();
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| i != points->End(); ++i)
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| {
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| // Get the point index from the point container iterator
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| int idx = i->Index();
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| // Set the vtk point at the index with the the coord array from itk
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| // itk returns a const pointer, but vtk is not const correct, so
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| // we have to use a const cast to get rid of the const
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| vpoints->SetPoint(idx, const_cast<float*>(i->Value().GetDataPointer()));
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| }
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| // Set the points on the vtk grid
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| unstructuredGrid->SetPoints(vpoints);
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| | |
| // Now create the cells using the MulitVisitor
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| // 1. Create a MultiVisitor
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| MeshType::CellType::MultiVisitor::Pointer mv =
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| MeshType::CellType::MultiVisitor::New();
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| // 2. Create a triangle and quadrilateral visitor
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| typedef itk::CellInterfaceVisitorImplementation<
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| float, MeshType::CellTraits,
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| itk::TriangleCell< itk::CellInterface<MeshType::PixelType, MeshType::CellTraits > >,
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| VistVTKCellsClass> TriangleVisitor;
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| | |
| typedef itk::CellInterfaceVisitorImplementation<
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| float, MeshType::CellTraits,
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| itk::QuadrilateralCell< itk::CellInterface<MeshType::PixelType, MeshType::CellTraits > >,
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| VistVTKCellsClass> QuadrilateralVisitor;
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| | |
| TriangleVisitor::Pointer tv = TriangleVisitor::New();
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| QuadrilateralVisitor::Pointer qv = QuadrilateralVisitor::New();
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| // 3. Set up the visitors
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| int vtkCellCount = 0; // running counter for current cell being inserted into vtk
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| int numCells = mesh->GetNumberOfCells();
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| int *types = new int[numCells]; // type array for vtk
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| // create vtk cells and estimate the size
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| vtkCellArray* cells = vtkCellArray::New();
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| cells->EstimateSize(numCells, 4);
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| // Set the TypeArray CellCount and CellArray for both visitors
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| tv->SetTypeArray(types);
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| tv->SetCellCounter(&vtkCellCount);
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| tv->SetCellArray(cells);
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| qv->SetTypeArray(types);
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| qv->SetCellCounter(&vtkCellCount);
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| qv->SetCellArray(cells);
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| // add the visitors to the multivisitor
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| mv->AddVisitor(tv);
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| mv->AddVisitor(qv);
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| // Now ask the mesh to accept the multivisitor which
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| // will Call Visit for each cell in the mesh that matches the
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| // cell types of the visitors added to the MultiVisitor
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| mesh->Accept(mv);
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| | |
| // Now set the cells on the vtk grid with the type array and cell array
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| unstructuredGrid->SetCells(types, cells);
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| std::cout << "Unstructured grid has " << unstructuredGrid->GetNumberOfCells() << " cells." << std::endl;
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| | |
| // Clean up vtk objects (no vtkSmartPointer ... )
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| cells->Delete();
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| vpoints->Delete();
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| | |
| }
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| </source>
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| {{ITKCMakeLists|ConvertToVTK}}
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