# CameraModel1

VTKExamples/Cxx/Visualization/CameraModel1

### Description

This example illustrates the camera movement around the focal point.

Note

For camera movement centered at the camera position see CameraModel2.

Note

This is an adaptation of the code written by Chung Kai Lun Pete.

Note

This example corresponds to Figure 3-12 in the VTK Text.

Info

See Figure 3-12 in Chapter 3 the VTK Textbook.

Other Languages

See (Python)

### Code

CameraModel1.cxx

    /*
       Adaptation of the code by
            Author: Chung Kai Lun Peter
            Email: hkpeterpeter@gmail.com
            File:
                    demo_vtk_camera_1.cpp
            Purpose:
                    Ported from camera.tcl from the VTK textbook.
                    It illustrates the camera model of VTK.
    */

    #include <vtkSmartPointer.h>

    #include <vtkAppendFilter.h>
    #include <vtkCellArray.h>
    #include <vtkConeSource.h>
    #include <vtkContourFilter.h>
    #include <vtkCubeSource.h>
    #include <vtkDataSetMapper.h>
    #include <vtkImplicitModeller.h>
    #include <vtkLODActor.h>
    #include <vtkPoints.h>
    #include <vtkPolyData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkRotationalExtrusionFilter.h>
    #include <vtkSphereSource.h>
    #include <vtkTextActor.h>
    #include <vtkTextProperty.h>
    #include <vtkTransform.h>
    #include <vtkTransformFilter.h>
    #include <vtkTransformPolyDataFilter.h>
    #include <vtkWarpTo.h>

    #include <vtkCamera.h>
    #include <vtkNamedColors.h>
    #include <vtkProperty.h>

    #include <algorithm>
    #include <array>

    int main(int /* argc */, char* /* argv */ [])
    {

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

      // Set the colors.
      std::array<unsigned char , 4> azArrowColor{{255, 77, 77}};
        colors->SetColor("AzimuthArrowColor", azArrowColor.data());
      std::array<unsigned char , 4> elevArrowColor{{77, 255, 77}};
        colors->SetColor("ElevationArrowColor", elevArrowColor.data());
      std::array<unsigned char , 4> rollArrowColor{{255, 255, 77}};
        colors->SetColor("RollArrowColor", rollArrowColor.data());
      std::array<unsigned char , 4> spikeColor{{255, 77, 255}};
        colors->SetColor("SpikeColor", spikeColor.data());
      // Set the background color.
      std::array<unsigned char , 4> bkg{{26, 51, 102}};
        colors->SetColor("BkgColor", bkg.data());

      // Create the RenderWindow, Renderer and both Actors
      //
      vtkSmartPointer<vtkRenderer> ren1 = vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renWin =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(ren1);
      vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renWin);

      // create a camera model
      vtkSmartPointer<vtkConeSource> camCS = vtkSmartPointer<vtkConeSource>::New();
      camCS->SetHeight(1.5);
      camCS->SetResolution(12);
      camCS->SetRadius(0.4);

      vtkSmartPointer<vtkCubeSource> camCBS = vtkSmartPointer<vtkCubeSource>::New();
      camCBS->SetXLength(1.5);
      camCBS->SetZLength(0.8);
      camCBS->SetCenter(0.4, 0, 0);

      vtkSmartPointer<vtkAppendFilter> camAPD =
        vtkSmartPointer<vtkAppendFilter>::New();
      camAPD->AddInputConnection(camCS->GetOutputPort());
      camAPD->AddInputConnection(camCBS->GetOutputPort());

      vtkSmartPointer<vtkDataSetMapper> camMapper =
        vtkSmartPointer<vtkDataSetMapper>::New();
      camMapper->SetInputConnection(camAPD->GetOutputPort());

      vtkSmartPointer<vtkLODActor> camActor = vtkSmartPointer<vtkLODActor>::New();
      camActor->SetMapper(camMapper);
      camActor->SetScale(2, 2, 2);

      // draw the arrows
      vtkSmartPointer<vtkPolyData> pd = vtkSmartPointer<vtkPolyData>::New();
      vtkSmartPointer<vtkCellArray> ca = vtkSmartPointer<vtkCellArray>::New();
      vtkSmartPointer<vtkPoints> fp = vtkSmartPointer<vtkPoints>::New();
      fp->InsertNextPoint(0, 1, 0);
      fp->InsertNextPoint(8, 1, 0);
      fp->InsertNextPoint(8, 2, 0);
      fp->InsertNextPoint(10, 0.01, 0);
      fp->InsertNextPoint(8, -2, 0);
      fp->InsertNextPoint(8, -1, 0);
      fp->InsertNextPoint(0, -1, 0);
      ca->InsertNextCell(7);
      ca->InsertCellPoint(0);
      ca->InsertCellPoint(1);
      ca->InsertCellPoint(2);
      ca->InsertCellPoint(3);
      ca->InsertCellPoint(4);
      ca->InsertCellPoint(5);
      ca->InsertCellPoint(6);
      pd->SetPoints(fp);
      pd->SetPolys(ca);

      vtkSmartPointer<vtkPolyData> pd2 = vtkSmartPointer<vtkPolyData>::New();
      vtkSmartPointer<vtkCellArray> ca2 = vtkSmartPointer<vtkCellArray>::New();
      vtkSmartPointer<vtkPoints> fp2 = vtkSmartPointer<vtkPoints>::New();
      fp2->InsertNextPoint(0, 1, 0);
      fp2->InsertNextPoint(8, 1, 0);
      fp2->InsertNextPoint(8, 2, 0);
      fp2->InsertNextPoint(10, 0.01, 0);
      ca2->InsertNextCell(4);
      ca2->InsertCellPoint(0);
      ca2->InsertCellPoint(1);
      ca2->InsertCellPoint(2);
      ca2->InsertCellPoint(3);
      pd2->SetPoints(fp2);
      pd2->SetLines(ca2);

      vtkSmartPointer<vtkImplicitModeller> arrowIM =
        vtkSmartPointer<vtkImplicitModeller>::New();
      arrowIM->SetInputData(pd);
      arrowIM->SetSampleDimensions(50, 20, 8);

      vtkSmartPointer<vtkContourFilter> arrowCF =
        vtkSmartPointer<vtkContourFilter>::New();
      arrowCF->SetInputConnection(arrowIM->GetOutputPort());
      arrowCF->SetValue(0, 0.2);

      vtkSmartPointer<vtkWarpTo> arrowWT = vtkSmartPointer<vtkWarpTo>::New();
      arrowWT->SetInputConnection(arrowCF->GetOutputPort());
      arrowWT->SetPosition(5, 0, 5);
      arrowWT->SetScaleFactor(0.85);
      arrowWT->AbsoluteOn();

      vtkSmartPointer<vtkTransform> arrowT = vtkSmartPointer<vtkTransform>::New();
      arrowT->RotateY(60);
      arrowT->Translate(-1.33198, 0, -1.479);
      arrowT->Scale(1, 0.5, 1);

      vtkSmartPointer<vtkTransformFilter> arrowTF =
        vtkSmartPointer<vtkTransformFilter>::New();
      arrowTF->SetInputConnection(arrowWT->GetOutputPort());
      arrowTF->SetTransform(arrowT);

      vtkSmartPointer<vtkDataSetMapper> arrowMapper =
        vtkSmartPointer<vtkDataSetMapper>::New();
      arrowMapper->SetInputConnection(arrowTF->GetOutputPort());
      arrowMapper->ScalarVisibilityOff();

      // draw the azimuth arrows
      vtkSmartPointer<vtkLODActor> a1Actor = vtkSmartPointer<vtkLODActor>::New();
      a1Actor->SetMapper(arrowMapper);
      a1Actor->RotateZ(180);
      a1Actor->SetPosition(1, 0, -1);
      a1Actor->GetProperty()->SetColor(
        colors->GetColor3d("AzimuthArrowColor").GetData());
      a1Actor->GetProperty()->SetSpecularColor(
        colors->GetColor3d("White").GetData());
      a1Actor->GetProperty()->SetSpecular(0.3);
      a1Actor->GetProperty()->SetSpecularPower(20);
      a1Actor->GetProperty()->SetAmbient(0.2);
      a1Actor->GetProperty()->SetDiffuse(0.8);

      vtkSmartPointer<vtkLODActor> a2Actor = vtkSmartPointer<vtkLODActor>::New();
      a2Actor->SetMapper(arrowMapper);
      a2Actor->RotateZ(180);
      a2Actor->RotateX(180);
      a2Actor->SetPosition(1, 0, 1);
      a2Actor->GetProperty()->SetColor(
        colors->GetColor3d("AzimuthArrowColor").GetData());
      a2Actor->GetProperty()->SetSpecularColor(
        colors->GetColor3d("White").GetData());
      a2Actor->GetProperty()->SetSpecular(0.3);
      a2Actor->GetProperty()->SetSpecularPower(20);
      a2Actor->GetProperty()->SetAmbient(0.2);
      a2Actor->GetProperty()->SetDiffuse(0.8);

      // draw the elevation arrows
      vtkSmartPointer<vtkLODActor> a3Actor = vtkSmartPointer<vtkLODActor>::New();
      a3Actor->SetMapper(arrowMapper);
      a3Actor->RotateZ(180);
      a3Actor->RotateX(90);
      a3Actor->SetPosition(1, -1, 0);
      a3Actor->GetProperty()->SetColor(
        colors->GetColor3d("ElevationArrowColor").GetData());
      a3Actor->GetProperty()->SetSpecularColor(
        colors->GetColor3d("White").GetData());
      a3Actor->GetProperty()->SetSpecular(0.3);
      a3Actor->GetProperty()->SetSpecularPower(20);
      a3Actor->GetProperty()->SetAmbient(0.2);
      a3Actor->GetProperty()->SetDiffuse(0.8);

      vtkSmartPointer<vtkLODActor> a4Actor = vtkSmartPointer<vtkLODActor>::New();
      a4Actor->SetMapper(arrowMapper);
      a4Actor->RotateZ(180);
      a4Actor->RotateX(-90);
      a4Actor->SetPosition(1, 1, 0);
      a4Actor->GetProperty()->SetColor(
        colors->GetColor3d("ElevationArrowColor").GetData());
      a4Actor->GetProperty()->SetSpecularColor(
        colors->GetColor3d("White").GetData());
      a4Actor->GetProperty()->SetSpecular(0.3);
      a4Actor->GetProperty()->SetSpecularPower(20);
      a4Actor->GetProperty()->SetAmbient(0.2);
      a4Actor->GetProperty()->SetDiffuse(0.8);

      // draw the DOP
      vtkSmartPointer<vtkTransform> arrowT2 = vtkSmartPointer<vtkTransform>::New();
      arrowT2->Scale(1, 0.6, 1);
      arrowT2->RotateY(90);

      vtkSmartPointer<vtkTransformPolyDataFilter> arrowTF2 =
        vtkSmartPointer<vtkTransformPolyDataFilter>::New();
      arrowTF2->SetInputData(pd2);
      arrowTF2->SetTransform(arrowT2);

      vtkSmartPointer<vtkRotationalExtrusionFilter> arrowREF =
        vtkSmartPointer<vtkRotationalExtrusionFilter>::New();
      arrowREF->SetInputConnection(arrowTF2->GetOutputPort());
      arrowREF->CappingOff();
      arrowREF->SetResolution(30);

      vtkSmartPointer<vtkPolyDataMapper> spikeMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      spikeMapper->SetInputConnection(arrowREF->GetOutputPort());

      vtkSmartPointer<vtkLODActor> a5Actor = vtkSmartPointer<vtkLODActor>::New();
      a5Actor->SetMapper(spikeMapper);
      a5Actor->SetScale(.3, .3, .6);
      a5Actor->RotateY(90);
      a5Actor->SetPosition(-2, 0, 0);
      a5Actor->GetProperty()->SetColor(colors->GetColor3d("SpikeColor").GetData());
      a5Actor->GetProperty()->SetAmbient(0.2);
      a5Actor->GetProperty()->SetDiffuse(0.8);

      // focal point
      vtkSmartPointer<vtkSphereSource> fps =
        vtkSmartPointer<vtkSphereSource>::New();
      fps->SetRadius(0.5);
      vtkSmartPointer<vtkPolyDataMapper> fpMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      fpMapper->SetInputConnection(fps->GetOutputPort());
      vtkSmartPointer<vtkLODActor> fpActor = vtkSmartPointer<vtkLODActor>::New();
      fpActor->SetMapper(fpMapper);
      fpActor->SetPosition(-9, 0, 0);
      fpActor->GetProperty()->SetSpecularColor(
        colors->GetColor3d("White").GetData());
      fpActor->GetProperty()->SetSpecular(0.3);
      fpActor->GetProperty()->SetAmbient(0.2);
      fpActor->GetProperty()->SetDiffuse(0.8);
      fpActor->GetProperty()->SetSpecularPower(20);

      // create the roll arrows
      vtkSmartPointer<vtkWarpTo> arrowWT2 = vtkSmartPointer<vtkWarpTo>::New();
      arrowWT2->SetInputConnection(arrowCF->GetOutputPort());
      arrowWT2->SetPosition(5, 0, 2.5);
      arrowWT2->SetScaleFactor(0.95);
      arrowWT2->AbsoluteOn();

      vtkSmartPointer<vtkTransform> arrowT3 = vtkSmartPointer<vtkTransform>::New();
      arrowT3->Translate(-2.50358, 0, -1.70408);
      arrowT3->Scale(0.5, 0.3, 1);

      vtkSmartPointer<vtkTransformFilter> arrowTF3 =
        vtkSmartPointer<vtkTransformFilter>::New();
      arrowTF3->SetInputConnection(arrowWT2->GetOutputPort());
      arrowTF3->SetTransform(arrowT3);

      vtkSmartPointer<vtkDataSetMapper> arrowMapper2 =
        vtkSmartPointer<vtkDataSetMapper>::New();
      arrowMapper2->SetInputConnection(arrowTF3->GetOutputPort());
      arrowMapper2->ScalarVisibilityOff();

      // draw the roll arrows
      vtkSmartPointer<vtkLODActor> a6Actor = vtkSmartPointer<vtkLODActor>::New();
      a6Actor->SetMapper(arrowMapper2);
      a6Actor->RotateZ(90);
      a6Actor->SetPosition(-4, 0, 0);
      a6Actor->SetScale(1.5, 1.5, 1.5);
      a6Actor->GetProperty()->SetColor(
        colors->GetColor3d("RollArrowColor").GetData());
      a6Actor->GetProperty()->SetSpecularColor(
        colors->GetColor3d("White").GetData());
      a6Actor->GetProperty()->SetSpecular(0.3);
      a6Actor->GetProperty()->SetSpecularPower(20);
      a6Actor->GetProperty()->SetAmbient(0.2);
      a6Actor->GetProperty()->SetDiffuse(0.8);

      // Add the actors to the renderer, set the background and size
      ren1->AddActor(camActor);
      ren1->AddActor(a1Actor);
      ren1->AddActor(a2Actor);
      ren1->AddActor(a3Actor);
      ren1->AddActor(a4Actor);
      ren1->AddActor(a5Actor);
      ren1->AddActor(a6Actor);
      ren1->AddActor(fpActor);
      ren1->SetBackground(colors->GetColor3d("BkgColor").GetData());
      ren1->SetBackground(colors->GetColor3d("SlateGray").GetData());
      renWin->SetSize(640, 480);

      // render the image

      vtkCamera* cam1 = (ren1->GetActiveCamera());
      ren1->ResetCamera();
      cam1->Azimuth(150);
      cam1->Elevation(30);
      cam1->Dolly(1.5);
      ren1->ResetCameraClippingRange();

      // Create a TextActor for azimuth  (a1 and a2 actor's color)
      vtkSmartPointer<vtkTextActor> text = vtkSmartPointer<vtkTextActor>::New();
      text->SetInput("Azimuth");
      vtkTextProperty* tprop = text->GetTextProperty();
      tprop->SetFontFamilyToArial();
      tprop->ShadowOff();
      tprop->SetLineSpacing(1.0);
      tprop->SetFontSize(36);
      tprop->SetColor(a1Actor->GetProperty()->GetColor());
      text->SetDisplayPosition(20, 50);
      ren1->AddActor2D(text);

      // Create a TextActor for elevation  (a3 and a4 actor's color)
      vtkSmartPointer<vtkTextActor> text2 = vtkSmartPointer<vtkTextActor>::New();
      text2->SetInput("Elevation");
      tprop = text2->GetTextProperty();
      tprop->SetFontFamilyToArial();
      tprop->ShadowOff();
      tprop->SetLineSpacing(1.0);
      tprop->SetFontSize(36);
      tprop->SetColor(a3Actor->GetProperty()->GetColor());
      text2->SetDisplayPosition(20, 100);
      ren1->AddActor2D(text2);

      // Create a TextActor for roll (a6 actor's color)
      vtkSmartPointer<vtkTextActor> text3 = vtkSmartPointer<vtkTextActor>::New();
      text3->SetInput("Roll");
      tprop = text3->GetTextProperty();
      tprop->SetFontFamilyToArial();
      tprop->ShadowOff();
      tprop->SetLineSpacing(1.0);
      tprop->SetFontSize(36);
      tprop->SetColor(a6Actor->GetProperty()->GetColor());
      text3->SetDisplayPosition(20, 150);
      ren1->AddActor2D(text3);

      renWin->Render();
      iren->Initialize();
      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(CameraModel1)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonCore
      vtkCommonDataModel
      vtkCommonTransforms
      vtkFiltersCore
      vtkFiltersGeneral
      vtkFiltersHybrid
      vtkFiltersModeling
      vtkFiltersSources
      vtkInteractionStyle
      vtkRenderingContextOpenGL2
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingGL2PSOpenGL2
      vtkRenderingLOD
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping CameraModel1: ${VTK_NOT_FOUND_MESSAGE}")
      return ()
    endif()
    message (STATUS "VTK_VERSION: ${VTK_VERSION}")
    if (VTK_VERSION VERSION_LESS "8.90.0")
      # old system
      include(${VTK_USE_FILE})
      add_executable(CameraModel1 MACOSX_BUNDLE CameraModel1.cxx )
      target_link_libraries(CameraModel1 PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(CameraModel1 MACOSX_BUNDLE CameraModel1.cxx )
      target_link_libraries(CameraModel1 PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS CameraModel1
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build CameraModel1

Click here to download CameraModel1 and its CMakeLists.txt file. Once the tarball CameraModel1.tar has been downloaded and extracted,

    cd CameraModel1/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:

    ./CameraModel1

WINDOWS USERS

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