# RandomProbe

VTKExamples/Cxx/Visualization/RandomProbe

### Code

RandomProbe.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkSampleFunction.h>
    #include <vtkSphereSource.h>
    #include <vtkCone.h>
    #include <vtkGlyph3D.h>
    #include <vtkProbeFilter.h>
    #include <vtkPointSource.h>
    #include <vtkThreshold.h>
    #include <vtkThresholdPoints.h>
    #include <vtkImageData.h>
    #include <vtkPointData.h>

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

    int main(int argc, char *argv[])
    {
      int resolution = 50;
      if (argc > 1)
      {
        resolution = atoi(argv[1]);
      }

      // Create a sampled cone
      vtkSmartPointer<vtkCone> implicitCone =
        vtkSmartPointer<vtkCone>::New();
      implicitCone->SetAngle(30.0);

      double radius = 1.0;
      vtkSmartPointer<vtkSampleFunction> sampledCone =
        vtkSmartPointer<vtkSampleFunction>::New();
      sampledCone->SetSampleDimensions(resolution, resolution, resolution);
      double xMin = -radius * 2.0;
      double xMax =  radius * 2.0;
      sampledCone->SetModelBounds(xMin, xMax,
                                  xMin, xMax,
                                  xMin, xMax);
      sampledCone->SetImplicitFunction(implicitCone);

      vtkSmartPointer<vtkThreshold> thresholdCone =
        vtkSmartPointer<vtkThreshold>:: New();
      thresholdCone->SetInputConnection(sampledCone->GetOutputPort());
      thresholdCone->ThresholdByLower(0);

      vtkSmartPointer<vtkPointSource> randomPoints =
        vtkSmartPointer<vtkPointSource>::New();
      randomPoints->SetCenter (0.0, 0.0, 0.0);
      randomPoints->SetNumberOfPoints(10000);
      randomPoints->SetDistributionToUniform();
      randomPoints->SetRadius(xMax);

      // Probe the cone dataset with random points
      vtkSmartPointer<vtkProbeFilter> randomProbe =
        vtkSmartPointer<vtkProbeFilter>::New();
      randomProbe->SetInputConnection(0, randomPoints->GetOutputPort());
      randomProbe->SetInputConnection(1, thresholdCone->GetOutputPort());
      randomProbe->Update();
      randomProbe->GetOutput()->GetPointData()->SetActiveScalars("vtkValidPointMask");

      vtkSmartPointer<vtkThresholdPoints> selectPoints =
        vtkSmartPointer<vtkThresholdPoints>::New();
      selectPoints->SetInputConnection(randomProbe->GetOutputPort());
      selectPoints->ThresholdByUpper(1.0);

      vtkSmartPointer<vtkSphereSource> sphere =
        vtkSmartPointer<vtkSphereSource>::New();
      sphere->SetRadius(.05);

      vtkSmartPointer<vtkGlyph3D> glyph =
        vtkSmartPointer<vtkGlyph3D>::New();
    #if VTK_MAJOR_VERSION <= 5
      glyph->SetSource(sphere->GetOutput());
      glyph->SetInput(selectPoints->GetOutput());
    #else
      glyph->SetSourceConnection(sphere->GetOutputPort());
      glyph->SetInputConnection(selectPoints->GetOutputPort());
    #endif

      // Create a mapper and actor
      vtkSmartPointer<vtkDataSetMapper> mapper =
        vtkSmartPointer<vtkDataSetMapper>::New();
      mapper->SetInputConnection(glyph->GetOutputPort());
      mapper->ScalarVisibilityOff();
      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      // Visualize
      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(actor);
      renderer->SetBackground(.1, .5, .8);

      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(RandomProbe)

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

    add_executable(RandomProbe MACOSX_BUNDLE RandomProbe.cxx )

    target_link_libraries(RandomProbe ${VTK_LIBRARIES})

### Download and Build RandomProbe

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

    cd RandomProbe/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:

    ./RandomProbe

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