ModifiedBSPTreeExtractCells

VTKExamples/Cxx/DataStructures/ModifiedBSPTreeExtractCells


Code

ModifiedBSPTreeExtractCells.cxx

#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkPoints.h>
#include <vtkIdList.h>
#include <vtkPolyData.h>
#include <vtkPointData.h>
#include <vtkLine.h>
#include <vtkLineSource.h>
#include <vtkExtractCells.h>
#include <vtkModifiedBSPTree.h>

#include <vtkPolyDataMapper.h>
#include <vtkDataSetMapper.h>
#include <vtkActor.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>

int main(int, char *[])
{
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetPhiResolution(7);
  sphereSource->SetThetaResolution(15);
  sphereSource->Update();

  // Create the locator
  vtkSmartPointer<vtkModifiedBSPTree> tree =
    vtkSmartPointer<vtkModifiedBSPTree>::New();
  tree->SetDataSet(sphereSource->GetOutput());

  // Intersect the locator with the line
  double lineP0[3] = {-0.6, -0.6, -0.6};
  double lineP1[3] = {.6, .6, .6};
  vtkSmartPointer<vtkPoints> intersectPoints =
    vtkSmartPointer<vtkPoints>::New();

  vtkSmartPointer<vtkIdList> intersectCells =
    vtkSmartPointer<vtkIdList>::New();

  double tol = 1.e-8;
  tree->IntersectWithLine(lineP0, lineP1, tol,
                          intersectPoints,
                          intersectCells);

  std::cout << "NumPoints: " << intersectPoints->GetNumberOfPoints()
            << std::endl;

  // Display list of intersections
  double intersection[3];
  for(int i = 0; i < intersectPoints->GetNumberOfPoints(); i++ )
  {
    intersectPoints->GetPoint(i, intersection);
    std::cout << "\tPoint Intersection " << i << ": "
              << intersection[0] << ", "
              << intersection[1] << ", "
              << intersection[2] << std::endl;
  }

  std::cout << "NumCells: " << intersectCells->GetNumberOfIds()
            << std::endl;

  vtkIdType cellId;
  for(int i = 0; i < intersectCells->GetNumberOfIds(); i++ )
  {
    cellId = intersectCells->GetId(i);
    std::cout << "\tCellId " << i << ": "
              << cellId << std::endl;
  }

  // Render the line, sphere and intersected cells
  vtkSmartPointer<vtkLineSource> lineSource =
    vtkSmartPointer<vtkLineSource>::New();
  lineSource->SetPoint1(lineP0);
  lineSource->SetPoint2(lineP1);

  vtkSmartPointer<vtkPolyDataMapper> lineMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  lineMapper->SetInputConnection(lineSource->GetOutputPort());
  vtkSmartPointer<vtkActor> lineActor =
    vtkSmartPointer<vtkActor>::New();
  lineActor->SetMapper(lineMapper);

  vtkSmartPointer<vtkPolyDataMapper> sphereMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  sphereMapper->SetInputConnection(sphereSource->GetOutputPort());
  vtkSmartPointer<vtkActor> sphereActor =
    vtkSmartPointer<vtkActor>::New();
  sphereActor->SetMapper(sphereMapper);
  sphereActor->GetProperty()->SetRepresentationToWireframe();
  sphereActor->GetProperty()->SetColor(0.89,0.81,0.34);

  vtkSmartPointer<vtkExtractCells> cellSource =
    vtkSmartPointer<vtkExtractCells>::New();
  cellSource->SetInputConnection(sphereSource->GetOutputPort());
  cellSource->SetCellList(intersectCells);

  vtkSmartPointer<vtkDataSetMapper> cellMapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  cellMapper->SetInputConnection(cellSource->GetOutputPort());
  vtkSmartPointer<vtkActor> cellActor =
    vtkSmartPointer<vtkActor>::New();
  cellActor->SetMapper(cellMapper);
  cellActor->GetProperty()->SetColor(1.0, 0.3882, 0.2784);

  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  renderer->AddActor(lineActor);
  renderer->AddActor(sphereActor);
  renderer->AddActor(cellActor);

  renderer->SetBackground(.4, .5, .6);
  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(ModifiedBSPTreeExtractCells)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(ModifiedBSPTreeExtractCells MACOSX_BUNDLE ModifiedBSPTreeExtractCells.cxx )

target_link_libraries(ModifiedBSPTreeExtractCells ${VTK_LIBRARIES})

Download and Build ModifiedBSPTreeExtractCells

Click here to download ModifiedBSPTreeExtractCells and its CMakeLists.txt file. Once the tarball ModifiedBSPTreeExtractCells.tar has been downloaded and extracted,

cd ModifiedBSPTreeExtractCells/build 

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./ModifiedBSPTreeExtractCells

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.