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

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Code¶

MultipleActors.cxx

#include <vtkActor.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkNamedColors.h>
#include <vtkNew.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
  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.