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LightActor

web-test/Cxx/Lighting/LightActor

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Question

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Code

LightActor.cxx

#include <vtkCamera.h>
#include <vtkLight.h>
#include <vtkLightActor.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

#include <cstdlib>

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

  vtkNew<vtkRenderer> renderer;
  renderer->SetBackground(colors->GetColor3d("Black").GetData());

  // Display where the light is
  vtkNew<vtkLight> light;
  light->SetPositional(true); // without this line, the program crashes
  vtkNew<vtkLightActor> lightActor;
  lightActor->SetLight(light);
  renderer->AddViewProp(lightActor);
  lightActor->GetFrustumProperty()->SetColor(
      colors->GetColor3d("LavenderBlush").GetData());

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("LightActor");

  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  renderer->ResetCamera();
  renderer->ResetCameraClippingRange();

  auto camera = renderer->GetActiveCamera();
  camera->SetPosition(-2.17199, -2.50774, 2.18);
  camera->SetFocalPoint(-0.144661, -0.146372, 0.180482);
  camera->SetViewUp(0.0157883, 0.638203, 0.769706);
  camera->SetDistance(3.69921);
  camera->SetClippingRange(1.76133, 6.14753);

  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(LightActor)

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

if (NOT VTK_FOUND)
  message(FATAL_ERROR "LightActor: 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(LightActor MACOSX_BUNDLE LightActor.cxx )
  target_link_libraries(LightActor PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS LightActor
  MODULES ${VTK_LIBRARIES}
)

Download and Build LightActor

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

cd LightActor/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:

./LightActor

WINDOWS USERS

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