# Cone4

VTKExamples/Cxx/Rendering/Cone4

### Description

This example modifies vtkActor's properties and transformation matrix.

Info

See Figure 3-28 in Chapter 3 the VTK Textbook.

Other Languages

See (Python)

### Code

Cone4.cxx

    //
    // This example demonstrates the creation of multiple actors and the
    // manipulation of their properties and transformations. It is a
    // derivative of Cone.tcl, see that example for more information.
    //

    // First include the required header files for the VTK classes we are using.
    #include <vtkActor.h>
    #include <vtkCamera.h>
    #include <vtkConeSource.h>
    #include <vtkNamedColors.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>

    int main(int, char* [])
    {
      vtkSmartPointer<vtkNamedColors> colors =
        vtkSmartPointer<vtkNamedColors>::New();

      //
      // Next we create an instance of vtkConeSource and set some of its
      // properties. The instance of vtkConeSource "cone" is part of a
      // visualization pipeline (it is a source process object); it produces data
      // (output type is vtkPolyData) which other filters may process.
      //
      vtkSmartPointer<vtkConeSource> cone = vtkSmartPointer<vtkConeSource>::New();
      cone->SetHeight(3.0);
      cone->SetRadius(1.0);
      cone->SetResolution(10);

      //
      // In this example we terminate the pipeline with a mapper process object.
      // (Intermediate filters such as vtkShrinkPolyData could be inserted in
      // between the source and the mapper.)  We create an instance of
      // vtkPolyDataMapper to map the polygonal data into graphics primitives. We
      // connect the output of the cone source to the input of this mapper.
      //
      vtkSmartPointer<vtkPolyDataMapper> coneMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      coneMapper->SetInputConnection(cone->GetOutputPort());

      //
      // Create an actor to represent the first cone. The actor's properties are
      // modified to give it different surface properties. By default, an actor
      // is create with a property so the GetProperty() method can be used.
      //
      vtkSmartPointer<vtkActor> coneActor = vtkSmartPointer<vtkActor>::New();
      coneActor->SetMapper(coneMapper);
      coneActor->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());
      coneActor->GetProperty()->SetDiffuse(0.7);
      coneActor->GetProperty()->SetSpecular(0.4);
      coneActor->GetProperty()->SetSpecularPower(20);

      //
      // Create a property and directly manipulate it. Assign it to the
      // second actor.
      //
      vtkSmartPointer<vtkProperty> property = vtkSmartPointer<vtkProperty>::New();
      property->SetColor(colors->GetColor3d("Tomato").GetData());
      property->SetDiffuse(0.7);
      property->SetSpecular(0.4);
      property->SetSpecularPower(20);

      //
      // Create a second actor and a property. The property is directly
      // manipulated and then assigned to the actor. In this way, a single
      // property can be shared among many actors. Note also that we use the
      // same mapper as the first actor did. This way we avoid duplicating
      // geometry, which may save lots of memory if the geoemtry is large.
      vtkSmartPointer<vtkActor> coneActor2 = vtkSmartPointer<vtkActor>::New();
      coneActor2->SetMapper(coneMapper);
      coneActor2->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());
      coneActor2->SetProperty(property);
      coneActor2->SetPosition(0, 2, 0);

      //
      // Create the Renderer and assign actors to it. A renderer is like a
      // viewport. It is part or all of a window on the screen and it is
      // responsible for drawing the actors it has.  We also set the background
      // color here.
      //
      vtkSmartPointer<vtkRenderer> ren1 = vtkSmartPointer<vtkRenderer>::New();
      ren1->AddActor(coneActor);
      ren1->AddActor(coneActor2);
      ren1->SetBackground(colors->GetColor3d("LightSlateGray").GetData());

      //
      // Finally we create the render window which will show up on the screen.
      // We put our renderer into the render window using AddRenderer. We also
      // set the size to be 300 pixels by 300.
      //
      vtkSmartPointer<vtkRenderWindow> renWin =
        vtkSmartPointer<vtkRenderWindow>::New();
      renWin->AddRenderer(ren1);
      renWin->SetSize(640, 480);

      vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renWin);

      //
      // Now we loop over 60 degrees and render the cone each time.
      //
      ren1->GetActiveCamera()->Elevation(30);
      ren1->ResetCamera();
      for (int i = 0; i < 60; ++i)
      {
        // render the image
        renWin->Render();
        // rotate the active camera by one degree
        ren1->GetActiveCamera()->Azimuth(1);
      }

      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(Cone4)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkFiltersSources
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping Cone4: ${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(Cone4 MACOSX_BUNDLE Cone4.cxx )
      target_link_libraries(Cone4 PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(Cone4 MACOSX_BUNDLE Cone4.cxx )
      target_link_libraries(Cone4 PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS Cone4
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build Cone4

Click here to download Cone4 and its CMakeLists.txt file. Once the tarball Cone4.tar has been downloaded and extracted,

    cd Cone4/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:

    ./Cone4

WINDOWS USERS

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