1、ExtractEnclosedPoints

mark points as to whether they are inside a closed surface

vtkSelectEnclosedPoints is a filter that evaluates all the input points to determine whether they are in an enclosed surface. The filter produces a (0,1) mask (in the form of a vtkDataArray) that indicates whether points are outside (mask value=0) or inside (mask value=1) a provided surface. (The name of the output vtkDataArray is "SelectedPoints".)

Description

This example uses vtkExtractEnclosedPoints to select points that exist within a closed vtkPolyData surface. After reading a vtk polydata file, the example generates 10000 random points within the bounding box of the vtkPolyData.

If the polydata is not closed or is non-manifold, the filter does not create an output.
从下面的代码功能看，是在一个polydata内部生成了1000个点。如果polydata不封闭或者不是流形，filter不会输出结果。

#include <vtkSmartPointer.h>
#include <vtkExtractEnclosedPoints.h>

#include <vtkBYUReader.h>
#include <vtkOBJReader.h>
#include <vtkPLYReader.h>
#include <vtkPolyDataReader.h>
#include <vtkSTLReader.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkSphereSource.h>

#include <vtkGlyph3DMapper.h>
#include <vtkPoints.h>
#include <vtkActor.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkCamera.h>

#include <vtkNamedColors.h>
#include <vtksys/SystemTools.hxx>
#include <random>

namespace
{
    
    
vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName);
}

int main (int argc, char *argv[])
{
    
    
  vtkSmartPointer<vtkPolyData> polyData = ReadPolyData(argc > 1 ? argv[1] : "");
  std::mt19937 mt(4355412); //Standard mersenne_twister_engine
  double bounds[6];
  polyData->GetBounds(bounds);
  std::cout << "Bounds: "
            << bounds[0] << ", " << bounds[1] << " "
            << bounds[2] << ", " << bounds[3] << " "
            << bounds[4] << ", " << bounds[5] << std::endl;
  // Generate random points within the bounding box of the polydata
  std::uniform_real_distribution<double> distributionX(bounds[0], bounds[1]);
  std::uniform_real_distribution<double> distributionY(bounds[2], bounds[3]);
  std::uniform_real_distribution<double> distributionZ(bounds[4], bounds[5]);
  vtkSmartPointer<vtkPolyData> pointsPolyData =
    vtkSmartPointer<vtkPolyData>::New();
  vtkSmartPointer<vtkPoints> points =
    vtkSmartPointer<vtkPoints>::New();
  pointsPolyData->SetPoints(points);

  points->SetNumberOfPoints(10000);
  for (auto i = 0; i < 10000; ++i)
    {
    
    
      double point[3];
      point[0] = distributionX(mt);
      point[1] = distributionY(mt);
      point[2] = distributionZ(mt);
      points->SetPoint(i, point);
    }

  vtkSmartPointer<vtkExtractEnclosedPoints> extract =
    vtkSmartPointer<vtkExtractEnclosedPoints>::New();
  extract->SetSurfaceData(polyData);
  extract->SetInputData(pointsPolyData);
  extract->SetTolerance(.0001);
  extract->CheckSurfaceOn();

  vtkSmartPointer<vtkNamedColors> colors =
    vtkSmartPointer<vtkNamedColors>::New();

  vtkSmartPointer<vtkSphereSource> source = 
    vtkSmartPointer<vtkSphereSource>::New();
  source->SetRadius((bounds[1] - bounds[0]) * .005);

  vtkSmartPointer<vtkGlyph3DMapper> glyph3Dmapper = 
    vtkSmartPointer<vtkGlyph3DMapper>::New();
  glyph3Dmapper->SetSourceConnection(source->GetOutputPort());
  glyph3Dmapper->SetInputConnection(extract->GetOutputPort());

  vtkSmartPointer<vtkActor> glyphActor =
    vtkSmartPointer<vtkActor>::New();
  glyphActor->SetMapper(glyph3Dmapper);
  glyphActor->GetProperty()->SetDiffuseColor(colors->GetColor3d("Crimson").GetData());
  glyphActor->GetProperty()->SetSpecular(.6);
  glyphActor->GetProperty()->SetSpecularPower(30);
;

  // Visualize
  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputData(polyData);

  vtkSmartPointer<vtkProperty> backProp =
    vtkSmartPointer<vtkProperty>::New();
  backProp->SetDiffuseColor(colors->GetColor3d("Banana").GetData());
  backProp->SetSpecular(.6);
  backProp->SetSpecularPower(30);
;

  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  actor->SetBackfaceProperty(backProp);
  actor->GetProperty()->SetDiffuseColor(colors->GetColor3d("Crimson").GetData());
  actor->GetProperty()->SetSpecular(.6);
  actor->GetProperty()->SetSpecularPower(30);
  actor->GetProperty()->SetOpacity(.3);

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

  renderer->AddActor(actor);
  renderer->AddActor(glyphActor);
  renderer->SetBackground(colors->GetColor3d("Silver").GetData());
  renderer->UseHiddenLineRemovalOn();

  renderWindow->SetSize(640, 512);

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

  return EXIT_SUCCESS;
}

namespace
{
    
    
vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName)
{
    
    
  vtkSmartPointer<vtkPolyData> polyData;
  std::string extension = vtksys::SystemTools::GetFilenameLastExtension(std::string(fileName));
  if (extension == ".ply")
  {
    
    
    vtkSmartPointer<vtkPLYReader> reader =
      vtkSmartPointer<vtkPLYReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtp")
  {
    
    
    vtkSmartPointer<vtkXMLPolyDataReader> reader =
      vtkSmartPointer<vtkXMLPolyDataReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".obj")
  {
    
    
    vtkSmartPointer<vtkOBJReader> reader =
      vtkSmartPointer<vtkOBJReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".stl")
  {
    
    
    vtkSmartPointer<vtkSTLReader> reader =
      vtkSmartPointer<vtkSTLReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtk")
  {
    
    
    vtkSmartPointer<vtkPolyDataReader> reader =
      vtkSmartPointer<vtkPolyDataReader>::New();
    reader->SetFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".g")
  {
    
    
    vtkSmartPointer<vtkBYUReader> reader =
      vtkSmartPointer<vtkBYUReader>::New();
    reader->SetGeometryFileName (fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else
  {
    
    
    vtkSmartPointer<vtkSphereSource> source =
      vtkSmartPointer<vtkSphereSource>::New();
    source->Update();
    polyData = source->GetOutput();
  }
  return polyData;
}
}

运行结果：

Bounds: -0.487464, 0.487464 -0.487464, 0.487464 -0.5, 0.5

在这里插入图片描述

参考：ExtractEnclosedPoints

2、例子2

判断一个正方体是否在一个球内

// Demonstrate moving pieces and "snapping"

#include <vtkSelectEnclosedPoints.h>
#include <vtkRendererCollection.h>
#include <vtkPointData.h>
#include <vtkPolyDataMapper.h>
#include <vtkTransform.h>
#include <vtkLinearTransform.h>
#include <vtkTransformPolyDataFilter.h>
#include <vtkObjectFactory.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyData.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkCubeSource.h>
#include <vtkInteractorStyleTrackballActor.h>
#include <vtkInteractorStyleSwitch.h>

// Define interaction style
class MouseInteractorStyle6 : public vtkInteractorStyleTrackballActor
{
    
    
public:
  static MouseInteractorStyle6* New();
  vtkTypeMacro(MouseInteractorStyle6, vtkInteractorStyleTrackballActor);

  virtual void OnLeftButtonDown() override
  {
    
    
    std::cout << "Pressed left mouse button." << std::endl;
    // Forward events
    vtkInteractorStyleTrackballActor::OnLeftButtonDown();
  }

  virtual void OnMiddleButtonUp() override
  {
    
    
    //std::cout << "Pressed middle mouse button." << std::endl;

    int x = this->Interactor->GetEventPosition()[0];
    int y = this->Interactor->GetEventPosition()[1];
    this->FindPokedRenderer(x, y);
    this->FindPickedActor(x, y);

    if (this->CurrentRenderer == NULL || this->InteractionProp == NULL)
    {
    
    
      std::cout << "Nothing selected." << std::endl;
      return;
    }

    vtkSmartPointer<vtkPropCollection> actors =
      vtkSmartPointer<vtkPropCollection>::New();

    this->InteractionProp->GetActors(actors);
    actors->InitTraversal();
    vtkActor* actor = dynamic_cast<vtkActor*>(actors->GetNextProp());

    vtkPolyData* polydata = dynamic_cast<vtkPolyData*>(actor->GetMapper()->GetInputAsDataSet());

    vtkSmartPointer<vtkTransform> transform =
      vtkSmartPointer<vtkTransform>::New();
    transform->SetMatrix(actor->GetMatrix());

    vtkSmartPointer<vtkTransformPolyDataFilter> transformPolyData =
      vtkSmartPointer<vtkTransformPolyDataFilter>::New();
    transformPolyData->SetInputData(polydata);
    transformPolyData->SetTransform(transform);
    transformPolyData->Update();

    vtkSmartPointer<vtkSelectEnclosedPoints> selectEnclosedPoints =
      vtkSmartPointer<vtkSelectEnclosedPoints>::New();
    selectEnclosedPoints->SetInputConnection(transformPolyData->GetOutputPort());
    selectEnclosedPoints->SetSurfaceData(this->Sphere);
    selectEnclosedPoints->Update();

    vtkDataArray* insideArray = dynamic_cast<vtkDataArray*>(selectEnclosedPoints->GetOutput()->GetPointData()->GetArray("SelectedPoints"));

    bool inside = false;
    for(vtkIdType i = 0; i < insideArray->GetNumberOfTuples(); i++)
    {
    
    
      if(insideArray->GetComponent(i,0) == 1)
      {
    
    
        inside = true;
        break;
      }
    }

    if(inside)
    {
    
    
      std::cout << "A point of the cube is inside the sphere!" << std::endl;
      // Reset the cube to its original position
      //this->CubeActor->GetMatrix()->Identity();
      //this->CubeActor->SetOrigin(0,0,0);
      this->CubeActor->SetPosition(0,0,0);
      this->CubeActor->SetOrientation(0,0,0);

      this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer()->Render();
      this->Interactor->GetRenderWindow()->Render();
    }

    // Release interaction
    this->StopState();

  }

  virtual void OnRightButtonDown() override
  {
    
    
    std::cout << "Pressed right mouse button." << std::endl;
    // Forward events
    vtkInteractorStyleTrackballActor::OnRightButtonDown();
  }

  vtkPolyData* Sphere;
  vtkActor* CubeActor;
};
vtkStandardNewMacro(MouseInteractorStyle6);

int main (int, char *[])
{
    
    
  // Sphere
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetRadius(2);
  sphereSource->Update();

  vtkSmartPointer<vtkPolyDataMapper> sphereMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  sphereMapper->SetInputConnection(sphereSource->GetOutputPort());

  vtkSmartPointer<vtkActor> sphereActor =
    vtkSmartPointer<vtkActor>::New();
  sphereActor->SetMapper(sphereMapper);

  // Cube
  vtkSmartPointer<vtkCubeSource> cubeSource =
    vtkSmartPointer<vtkCubeSource>::New();
  cubeSource->SetCenter(5.0, 0.0, 0.0);
  cubeSource->Update();

  vtkSmartPointer<vtkPolyDataMapper> cubeMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  cubeMapper->SetInputConnection(cubeSource->GetOutputPort());

  vtkSmartPointer<vtkActor> cubeActor =
    vtkSmartPointer<vtkActor>::New();
  cubeActor->SetMapper(cubeMapper);

  // 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(sphereActor);
  renderer->AddActor(cubeActor);

  renderWindow->Render();

  vtkSmartPointer<MouseInteractorStyle6> style =
    vtkSmartPointer<MouseInteractorStyle6>::New();
  style->Sphere = sphereSource->GetOutput();
  style->CubeActor = cubeActor;

  renderWindowInteractor->SetInteractorStyle(style);

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

在这里插入图片描述
关键代码：
遍历所有点，如果存在点在里面则输出是，否则输出否。

vtkSmartPointer<vtkSelectEnclosedPoints> selectEnclosedPoints =
      vtkSmartPointer<vtkSelectEnclosedPoints>::New();
    selectEnclosedPoints->SetInputConnection(transformPolyData->GetOutputPort());
    selectEnclosedPoints->SetSurfaceData(this->Sphere);
    selectEnclosedPoints->Update();

    vtkDataArray* insideArray = dynamic_cast<vtkDataArray*>(selectEnclosedPoints->GetOutput()->GetPointData()->GetArray("SelectedPoints"));

    bool inside = false;
    for(vtkIdType i = 0; i < insideArray->GetNumberOfTuples(); i++)
    {
    
    
      if(insideArray->GetComponent(i,0) == 1)
      {
    
    
        inside = true;
        break;
      }
    }

VTK学习笔记（二十七）ExtractEnclosedPoints示例

VTK学习笔记（二十七）ExtractEnclosedPoints示例

1、ExtractEnclosedPoints

Description

2、例子2

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