How to clean duplicate points after cut-through cells using vtkTableBasedClipDataSet?

Support
1

HI, I 'm using vtkTableBasedClipDataSet to cut a cylinder. It works fairly well. But when cutting along a same plane(implicit function) multiple times, some duplicate points would present in the output. As a result, the render time drops dramatically.

The image below shows the situation.

image
image290×804 10.2 KB

I apply the vtkmCleanGrid to deal with it, but still the same result.

And here is my code:

#cpp
#include "RenderWindowUISingleInheritance.h"
#include "ui_RenderWindowUISingleInheritance.h"

#include <vtkGenericOpenGLRenderWindow.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>
#include <vtkVersion.h>
#include <vtkPlane.h>
#include <vtkXMLUnstructuredGridReader.h>
#include <vtkCallbackCommand.h>
#include <vtkIdFilter.h>
#include <vtkmCleanGrid.h>


namespace {

    void CallbackFunction(vtkObject* caller, long unsigned int vtkNotUsed(eventId),
        void* vtkNotUsed(clientData), void* vtkNotUsed(callData))
    {
        vtkRenderer* renderer = static_cast<vtkRenderer*>(caller);
        std::cout << "render time: " << renderer->GetLastRenderTimeInSeconds() << std::endl;
    }
}

RenderWindowUISingleInheritance::RenderWindowUISingleInheritance(
    QWidget* parent)
  : QMainWindow(parent), ui(new Ui::RenderWindowUISingleInheritance)
{
  this->ui->setupUi(this);
  cutTimer = new QTimer(this);

  vtkNew<vtkNamedColors> colors;
  vtkNew<vtkGenericOpenGLRenderWindow> renderWindow;
  this->ui->qvtkWidget->setRenderWindow(renderWindow);

  vtkNew<vtkXMLUnstructuredGridReader> Reader;
  Reader->SetFileName("../cylinder.vtu");
  Reader->Update();

  clipper = vtkSmartPointer<vtkTableBasedClipDataSet>::New();
  Source = vtkUnstructuredGrid::New();
  Source->DeepCopy(Reader->GetOutput());
  clipper->SetInputData(Source);

  Mapper = vtkSmartPointer<vtkDataSetMapper>::New();
  Actor = vtkSmartPointer<vtkActor>::New();
  Mapper->SetInputData(Source);
  Actor->SetMapper(Mapper);

  // VTK Renderer
  vtkNew<vtkRenderer> renderer;
  renderer->AddActor(Actor);
  renderer->SetBackground(colors->GetColor3d("SteelBlue").GetData());

  vtkNew<vtkCallbackCommand> rendererCallback;
  rendererCallback->SetCallback(CallbackFunction);
  renderer->AddObserver(vtkCommand::EndEvent, rendererCallback);

  this->ui->qvtkWidget->renderWindow()->AddRenderer(renderer);

  
  connect(cutTimer, &QTimer::timeout, [=]() {
      std::cout << "points befor clip = " << Source->GetNumberOfPoints() << std::endl;
      std::cout << "cells befor clip = " << Source->GetNumberOfCells() << std::endl;

      vtkNew<vtkPlane> plane;
      clipper->RemoveAllInputs();
      clipper->SetInputData(Source);
      clipper->SetClipFunction(plane);
      clipper->Update();
      Source->DeepCopy(clipper->GetOutput());

      std::cout << "points after clip = " << Source->GetNumberOfPoints() << std::endl;
      std::cout << "cells after clip = " << Source->GetNumberOfCells() << std::endl;
      std::cout << "=================================================== " << std::endl;
      std::cout <<  std::endl;
      
      vtkSmartPointer<vtkmCleanGrid> cg = vtkSmartPointer<vtkmCleanGrid>::New();
      cg->SetInputData(Source);

      vtkNew<vtkIdFilter> idFilter;
      idFilter->SetInputConnection(cg->GetOutputPort());
      idFilter->SetPointIds(1);
      idFilter->SetCellIds(1);
      idFilter->Update();

      Mapper->RemoveAllInputs();
      Mapper->SetInputData(idFilter->GetOutput());
      this->ui->qvtkWidget->renderWindow()->Render();
  });

  cutTimer->start(1000);
}

RenderWindowUISingleInheritance::~RenderWindowUISingleInheritance()
{
  delete this->ui;
}


#header
#ifndef RenderWindowUISingleInheritance_H
#define RenderWindowUISingleInheritance_H

#include <vtkSmartPointer.h>
#include <vtkUnstructuredGrid.h>
#include <vtkTableBasedClipDataSet.h>
#include <vtkDataSetMapper.h>
#include <QMainWindow>
#include <QTimer>

/*
 * See "The Single Inheritance Approach" in this link:
 * [Using a Designer UI File in Your C++
 * Application](https://doc.qt.io/qt-5/designer-using-a-ui-file.html)
 */
namespace Ui {
class RenderWindowUISingleInheritance;
}

class RenderWindowUISingleInheritance : public QMainWindow
{
  Q_OBJECT
public:
  // Constructor/Destructor
  explicit RenderWindowUISingleInheritance(QWidget* parent = nullptr);
  virtual ~RenderWindowUISingleInheritance();
  vtkSmartPointer<vtkTableBasedClipDataSet> clipper;
  vtkUnstructuredGrid* Source;
  vtkSmartPointer<vtkDataSetMapper> Mapper;
  vtkSmartPointer<vtkActor> Actor;
private:
  // Designer form
  Ui::RenderWindowUISingleInheritance* ui;
  QTimer* cutTimer;

public slots:
  
};

#endif

As far as I know, the vtkTableBasedClipDataSet will generate the least cell when clipping.
How can I address this problem?

2

Finally, I find vtkExtractGeometry is what I really need.