MultipleActors

VTKExamples/Cxx/Visualization/MultipleActors

Description

This example creates two spheres and renders them. The idea is to show that each object needs its own mapper and actor and then multiple actors can be added to a renderer.

Code

MultipleActors.cxx

#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyData.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkInteractorStyleTrackball.h>

int main (int, char *[])
{
  // Sphere 1
  vtkSmartPointer<vtkSphereSource> sphereSource1 = 
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource1->SetCenter(0.0, 0.0, 0.0);
  sphereSource1->SetRadius(4.0);
  sphereSource1->Update();

  vtkSmartPointer<vtkPolyDataMapper> mapper1 = 
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper1->SetInputConnection(sphereSource1->GetOutputPort());

  vtkSmartPointer<vtkActor> actor1 = 
    vtkSmartPointer<vtkActor>::New();
  actor1->SetMapper(mapper1);

  // Sphere 2
  vtkSmartPointer<vtkSphereSource> sphereSource2 = 
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource2->SetCenter(10.0, 0.0, 0.0);
  sphereSource2->SetRadius(3.0);

  // Create a mapper
  vtkSmartPointer<vtkPolyDataMapper> mapper2 = 
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper2->SetInputConnection(sphereSource2->GetOutputPort());

  // Create an actor
  vtkSmartPointer<vtkActor> actor2 = 
    vtkSmartPointer<vtkActor>::New();
  actor2->SetMapper(mapper2);

  // A renderer and render window
  vtkSmartPointer<vtkRenderer> renderer = 
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = 
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);

  // An interactor
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = 
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Add the actors to the scene
  renderer->AddActor(actor1);
  renderer->AddActor(actor2);
  renderer->SetBackground(1,1,1); // Background color white

  // Render
  renderWindow->Render();

  vtkSmartPointer<vtkInteractorStyleTrackballCamera> style = 
    vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New(); //like paraview

  renderWindowInteractor->SetInteractorStyle( style );

  // Begin mouse interaction
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(MultipleActors)

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

Download and Build MultipleActors

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

cd MultipleActors/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:

./MultipleActors

WINDOWS USERS

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