vtk – show bounding box by lines and surfaces

The post shows how to display bounding box of 3D model by lines and surfaces.

vtkSPtr<vtkPolyData> GetBoundsFacePolyData(double bounds[6])
{
    double x[8][3]={{bounds[0],bounds[2],bounds[4]}, {bounds[1],bounds[2],bounds[4]}, {bounds[1],bounds[3],bounds[4]}, {bounds[0],bounds[3],bounds[4]},
                    {bounds[0],bounds[2],bounds[5]}, {bounds[1],bounds[2],bounds[5]}, {bounds[1],bounds[3],bounds[5]}, {bounds[0],bounds[3],bounds[5]}};
    vtkIdType pts[6][4]={{0,1,2,3}, {4,5,6,7}, {0,1,5,4},
                         {1,2,6,5}, {2,3,7,6}, {3,0,4,7}};    

    vtkSPtrNew( points, vtkPoints );
    vtkSPtrNew( polys, vtkCellArray );
    vtkSPtrNew( polyData, vtkPolyData );

    for (int i=0; i<8; i++) points->InsertPoint(i,x[i]);
    for (int i=0; i<6; i++) polys->InsertNextCell(4,pts[i]);

    polyData->SetPoints(points);
    polyData->SetPolys(polys);
    return polyData;
}

vtkSPtr<vtkPolyData> GetBoundsPolyData(double bounds[6])
{
    std::vector<Point> pts;
    for( int i = 0; i < 2; ++i )
    {
        for( int j = 2; j < 4; ++j )
        {
            for( int k = 4; k < 6; ++k )
            {
                pts.push_back( Point( bounds[i], bounds[j], bounds[k] ) );
            }
        }
    }

    vtkSmartPointer<vtkPolyData> boundsPolydata =
            vtkSmartPointer<vtkPolyData>::New();
    vtkSmartPointer<vtkPoints> boundsPoints =
            vtkSmartPointer<vtkPoints>::New();
    for( int i = 0 ; i < 8; ++i )
    {
        boundsPoints->InsertNextPoint( pts[i].point );
    }
    boundsPolydata->SetPoints( boundsPoints );
    vtkSmartPointer<vtkCellArray> cells =
            vtkSmartPointer<vtkCellArray>::New();
    vtkIdType cell[2] = { 0, 1 };
    cells->InsertNextCell( 2, cell );
    cell[0] = 0; cell[1] = 2;
    cells->InsertNextCell( 2, cell );
    cell[0] = 3; cell[1] = 2;
    cells->InsertNextCell( 2, cell );
    cell[0] = 3; cell[1] = 1;
    cells->InsertNextCell( 2, cell );
    cell[0] = 4; cell[1] = 5;
    cells->InsertNextCell( 2, cell );
    cell[0] = 4; cell[1] = 6;
    cells->InsertNextCell( 2, cell );
    cell[0] = 7; cell[1] = 5;
    cells->InsertNextCell( 2, cell );
    cell[0] = 7; cell[1] = 6;
    cells->InsertNextCell( 2, cell );
    cell[0] = 1; cell[1] = 5;
    cells->InsertNextCell( 2, cell );
    cell[0] = 0; cell[1] = 4;
    cells->InsertNextCell( 2, cell );
    cell[0] = 2; cell[1] = 6;
    cells->InsertNextCell( 2, cell );
    cell[0] = 3; cell[1] = 7;
    cells->InsertNextCell( 2, cell );
    boundsPolydata->SetLines( cells );
    return boundsPolydata;
}

Surfaces:

.

Lines:

.

Complete code:

#include <iostream>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkActor.h>
#include <vtkConeSource.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkParametricFunctionSource.h>
#include <vtkParametricTorus.h>
#include <vtkProperty.h>

#include "point.hpp"

#define vtkSPtr vtkSmartPointer
#define vtkSPtrNew(Var, Type) vtkSPtr<Type> Var = vtkSPtr<Type>::New();

using namespace std;

vtkSPtr<vtkPolyData> GetBoundsFacePolyData(double bounds[6])
{
    double x[8][3]={{bounds[0],bounds[2],bounds[4]}, {bounds[1],bounds[2],bounds[4]}, {bounds[1],bounds[3],bounds[4]}, {bounds[0],bounds[3],bounds[4]},
                    {bounds[0],bounds[2],bounds[5]}, {bounds[1],bounds[2],bounds[5]}, {bounds[1],bounds[3],bounds[5]}, {bounds[0],bounds[3],bounds[5]}};
    vtkIdType pts[6][4]={{0,1,2,3}, {4,5,6,7}, {0,1,5,4},
                         {1,2,6,5}, {2,3,7,6}, {3,0,4,7}};

    vtkSPtrNew( points, vtkPoints );
    vtkSPtrNew( polys, vtkCellArray );
    vtkSPtrNew( polyData, vtkPolyData );

    for (int i=0; i<8; i++) points->InsertPoint(i,x[i]);
    for (int i=0; i<6; i++) polys->InsertNextCell(4,pts[i]);

    polyData->SetPoints(points);
    polyData->SetPolys(polys);
    return polyData;
}

vtkSPtr<vtkPolyData> GetBoundsPolyData(double bounds[6])
{
    std::vector<Point> pts;
    for( int i = 0; i < 2; ++i )
    {
        for( int j = 2; j < 4; ++j )
        {
            for( int k = 4; k < 6; ++k )
            {
                pts.push_back( Point( bounds[i], bounds[j], bounds[k] ) );
            }
        }
    }

    vtkSmartPointer<vtkPolyData> boundsPolydata =
            vtkSmartPointer<vtkPolyData>::New();
    vtkSmartPointer<vtkPoints> boundsPoints =
            vtkSmartPointer<vtkPoints>::New();
    for( int i = 0 ; i < 8; ++i )
    {
        boundsPoints->InsertNextPoint( pts[i].point );
    }
    boundsPolydata->SetPoints( boundsPoints );
    vtkSmartPointer<vtkCellArray> cells =
            vtkSmartPointer<vtkCellArray>::New();
    vtkIdType cell[2] = { 0, 1 };
    cells->InsertNextCell( 2, cell );
    cell[0] = 0; cell[1] = 2;
    cells->InsertNextCell( 2, cell );
    cell[0] = 3; cell[1] = 2;
    cells->InsertNextCell( 2, cell );
    cell[0] = 3; cell[1] = 1;
    cells->InsertNextCell( 2, cell );
    cell[0] = 4; cell[1] = 5;
    cells->InsertNextCell( 2, cell );
    cell[0] = 4; cell[1] = 6;
    cells->InsertNextCell( 2, cell );
    cell[0] = 7; cell[1] = 5;
    cells->InsertNextCell( 2, cell );
    cell[0] = 7; cell[1] = 6;
    cells->InsertNextCell( 2, cell );
    cell[0] = 1; cell[1] = 5;
    cells->InsertNextCell( 2, cell );
    cell[0] = 0; cell[1] = 4;
    cells->InsertNextCell( 2, cell );
    cell[0] = 2; cell[1] = 6;
    cells->InsertNextCell( 2, cell );
    cell[0] = 3; cell[1] = 7;
    cells->InsertNextCell( 2, cell );
    boundsPolydata->SetLines( cells );
    return boundsPolydata;
}

int main()
{
    vtkSPtrNew( source, vtkConeSource );
    source->Update();

    auto pd = source->GetOutput();
    pd->ComputeBounds();
    double bds[6];
    pd->GetBounds( bds );

    auto bdsPd = GetBoundsPolyData( bds );

    vtkSPtrNew( mapper, vtkPolyDataMapper );
    mapper->SetInputData( pd );

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

    vtkSPtrNew( bdsMapper, vtkPolyDataMapper );
    bdsMapper->SetInputData( bdsPd );

    vtkSPtrNew( bdsActor, vtkActor );
    bdsActor->SetMapper( bdsMapper );
    bdsActor->GetProperty()->SetColor( 1, 0, 0 );
    bdsActor->GetProperty()->SetOpacity( 0.5 );

    vtkSPtrNew( renderer, vtkRenderer );
    renderer->AddActor(actor);
    renderer->AddActor(bdsActor);
    renderer->SetBackground( 0, 0, 0 );

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

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

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