Show Point List By Line And Points

The article describe a simple way to display point id list on the original model. We use VTK to draw and show all scenes.

vtkSmartPointer<vtkPolyData> UShowData::ShowListByPoints(vtkSmartPointer<vtkPolyData> polyData, vtkSmartPointer<vtkIdList> list)
{
    vSPNew( result, vtkPolyData );
    vSPNew( resultPts, vtkPoints );
    vSPNew( resultVerts, vtkCellArray );
    for( int i = 0; i < list->GetNumberOfIds(); ++i )
    {
        auto ptId = list->GetId( i );
        if( ptId >= polyData->GetNumberOfPoints() || ptId < 0) continue;

        PointStruct pt( polyData->GetPoint( ptId ) );
        resultPts->InsertNextPoint( pt.GetPoint() );
        vtkIdType pts[1] = { i };
        resultVerts->InsertNextCell( 1, pts );
    }
    result->SetPoints( resultPts );
    result->SetVerts( resultVerts );
    result->Modified();
    return result;
}

vtkSmartPointer<vtkPolyData> UShowData::ShowListByLine(vtkSmartPointer<vtkPolyData> polyData, vtkSmartPointer<vtkIdList> list)
{
    vSPNew( result, vtkPolyData );
    vSPNew( resultPts, vtkPoints );
    vSPNew( resultLines, vtkCellArray );
    for( int i = 0; i < list->GetNumberOfIds(); ++i )
    {
        auto ptId = list->GetId( i );
        if( ptId >= polyData->GetNumberOfPoints() || ptId < 0) continue;

        PointStruct pt( polyData->GetPoint( ptId ) );
        resultPts->InsertNextPoint( pt.GetPoint() );
    }
    for( int i = 0; i < resultPts->GetNumberOfPoints()-1; ++i )
    {
        vtkIdType pts[2] = { i, i + 1 };
        resultLines->InsertNextCell( 2, pts );
    }
    result->SetPoints( resultPts );
    result->SetLines( resultLines );
    result->Modified();
    return result;
}


#include <iostream>

#include "UShowData.h"
#include <vtkSphereSource.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkProperty.h>

int main()
{
    vSPNew( source, vtkSphereSource );
    source->SetPhiResolution( 40 );
    source->SetThetaResolution( 40 );
    source->Update();

    vSPNew( list, vtkIdList );
    for( int i = 0; i < 20; i++ )
    {
        list->InsertNextId( i );
    }

    auto originData = source->GetOutput();

    UShowData showData;
    auto tmp = showData.ShowListByPoints( originData, list );

    vSPNew( dataMapper, vtkPolyDataMapper );
    dataMapper->SetInputData( tmp );

    vSPNew( dataActor, vtkActor );
    dataActor->SetMapper( dataMapper );
    dataActor->GetProperty()->SetLineWidth( 3 );
    dataActor->GetProperty()->SetPointSize( 3 );
    dataActor->GetProperty()->SetColor( 1, 0, 0 );

    vSPNew( mapper, vtkPolyDataMapper );
    mapper->SetInputData( originData );

    vSPNew( actor, vtkActor );
    actor->SetMapper( mapper );

    vSPNew( renderer, vtkRenderer );
    renderer->AddActor( dataActor );
    renderer->AddActor( actor );
    renderer->SetBackground( 0, 0, 0 );

    vSPNew( renderWindow, vtkRenderWindow );
    renderWindow->AddRenderer( renderer );

    vSPNew( renderWindowInteractor, vtkRenderWindowInteractor );
    renderWindowInteractor->SetRenderWindow( renderWindow );

    renderer->ResetCamera();
    renderWindow->Render();
    renderWindowInteractor->Start();
    return 0;
}