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MultipleActors

vtk-examples/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.

Other languages

See (Java)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

MultipleActors.cxx

#include <vtkActor.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  // Sphere 1
  vtkNew<vtkSphereSource> sphereSource1;
  sphereSource1->SetCenter(0.0, 0.0, 0.0);
  sphereSource1->SetRadius(4.0);
  sphereSource1->Update();

  vtkNew<vtkPolyDataMapper> mapper1;
  mapper1->SetInputConnection(sphereSource1->GetOutputPort());

  vtkNew<vtkActor> actor1;
  actor1->SetMapper(mapper1);
  actor1->GetProperty()->SetColor(colors->GetColor3d("MistyRose").GetData());

  // Sphere 2
  vtkNew<vtkSphereSource> sphereSource2;
  sphereSource2->SetCenter(10.0, 0.0, 0.0);
  sphereSource2->SetRadius(3.0);
  sphereSource2->Update();

  // Create a mapper
  vtkNew<vtkPolyDataMapper> mapper2;
  mapper2->SetInputConnection(sphereSource2->GetOutputPort());

  // Create an actor
  vtkNew<vtkActor> actor2;
  actor2->SetMapper(mapper2);
  actor2->GetProperty()->SetColor(colors->GetColor3d("Cornsilk").GetData());

  // A renderer and render window
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("MultipleActors");

  // An interactor
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Add the actors to the scene
  renderer->AddActor(actor1);
  renderer->AddActor(actor2);
  renderer->SetBackground(colors->GetColor3d("DarkSlateGray").GetData());

  // Render an image (lights and cameras are created automatically)
  renderWindow->Render();

  vtkNew<vtkInteractorStyleTrackballCamera> style;

  renderWindowInteractor->SetInteractorStyle(style);

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

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(MultipleActors)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  FiltersSources
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "MultipleActors: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
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}
)

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.