Light
VTKExamples/Cxx/Lighting/Light
Code
Light.cxx
#include <cstdlib>
#include <vtkVersion.h>
#include <vtkLightCollection.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkPlaneSource.h>
#include <vtkSphereSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkLight.h>
#include <vtkLightActor.h>
#include <vtkSmartPointer.h>
#include <vtkRenderWindowInteractor.h>
int main(int, char *[])
{
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
double lightPosition[3] = {0, 0, 1};
// Create a light
double lightFocalPoint[3] = {0,0,0};
vtkSmartPointer<vtkLight> light = vtkSmartPointer<vtkLight>::New();
light->SetLightTypeToSceneLight();
light->SetPosition(lightPosition[0], lightPosition[1], lightPosition[2]);
light->SetPositional(true); // required for vtkLightActor below
light->SetConeAngle(10);
light->SetFocalPoint(lightFocalPoint[0], lightFocalPoint[1], lightFocalPoint[2]);
light->SetDiffuseColor(1,0,0);
light->SetAmbientColor(0,1,0);
light->SetSpecularColor(0,0,1);
vtkLightCollection* originalLights = renderer->GetLights();
std::cout << "Originally there are " << originalLights->GetNumberOfItems() << " lights." << std::endl;
// renderer->AddLight(light); // can't do this here - must do this after the renderWindow->Render() below
// Display where the light is
vtkSmartPointer<vtkLightActor> lightActor = vtkSmartPointer<vtkLightActor>::New();
lightActor->SetLight(light);
renderer->AddViewProp(lightActor);
// Display where the light is focused
vtkSmartPointer<vtkSphereSource> lightFocalPointSphere = vtkSmartPointer<vtkSphereSource>::New();
lightFocalPointSphere->SetCenter(lightFocalPoint);
lightFocalPointSphere->SetRadius(.1);
lightFocalPointSphere->Update();
vtkSmartPointer<vtkPolyDataMapper> lightFocalPointMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
lightFocalPointMapper->SetInputConnection(lightFocalPointSphere->GetOutputPort());
vtkSmartPointer<vtkActor> lightFocalPointActor = vtkSmartPointer<vtkActor>::New();
lightFocalPointActor->SetMapper(lightFocalPointMapper);
lightFocalPointActor->GetProperty()->SetColor(1.0, 1.0, 0.0); //(R,G,B)
renderer->AddViewProp(lightFocalPointActor);
// Create a plane for the light to shine on
vtkSmartPointer<vtkPlaneSource> planeSource = vtkSmartPointer<vtkPlaneSource>::New();
planeSource->SetResolution(100, 100);
planeSource->Update();
vtkSmartPointer<vtkPolyDataMapper> planeMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
#if VTK_MAJOR_VERSION <= 5
planeMapper->SetInput(planeSource->GetOutput());
#else
planeMapper->SetInputData(planeSource->GetOutput());
#endif
vtkSmartPointer<vtkActor> planeActor = vtkSmartPointer<vtkActor>::New();
planeActor->SetMapper(planeMapper);
renderer->AddActor(planeActor);
vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);
renderWindow->Render();
std::cout << "Now there are " << originalLights->GetNumberOfItems() << " lights." << std::endl;
renderer->AddLight(light); // must do this after renderWindow->Render();
std::cout << "Now there are " << originalLights->GetNumberOfItems() << " lights." << std::endl;
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(Light)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(Light MACOSX_BUNDLE Light.cxx)
target_link_libraries(Light ${VTK_LIBRARIES})
Download and Build Light
Click here to download Light and its CMakeLists.txt file. Once the tarball Light.tar has been downloaded and extracted,
cd Light/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:
./Light
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.