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CameraBlur

vtk-examples/Cxx/Rendering/CameraBlur


Description

Example of motion blur.

Info

See Figure 7-37 in Chapter 7 in the VTK Textbook.

Other languages

See (Python)

Question

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

Code

CameraBlur.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkConeSource.h>
#include <vtkGlyph3D.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

#include <array>

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

  // Set the background color.
  std::array<unsigned char, 4> bkg{{26, 51, 102, 255}};
  colors->SetColor("Bkg", bkg.data());

  // Create the rendering objects.
  vtkNew<vtkRenderer> ren1;
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(ren1);
  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  // Create the pipeline, ball and spikes.
  vtkNew<vtkSphereSource> sphere;
  sphere->SetPhiResolution(7);
  sphere->SetThetaResolution(7);
  vtkNew<vtkPolyDataMapper> sphereMapper;
  sphereMapper->SetInputConnection(sphere->GetOutputPort());
  vtkNew<vtkActor> sphereActor;
  sphereActor->SetMapper(sphereMapper);
  vtkNew<vtkActor> sphereActor2;
  sphereActor2->SetMapper(sphereMapper);

  vtkNew<vtkConeSource> cone;
  cone->SetResolution(5);
  vtkNew<vtkGlyph3D> glyph;
  glyph->SetInputConnection(sphere->GetOutputPort());
  glyph->SetSourceConnection(cone->GetOutputPort());
  glyph->SetVectorModeToUseNormal();
  glyph->SetScaleModeToScaleByVector();
  glyph->SetScaleFactor(0.25);
  vtkNew<vtkPolyDataMapper> spikeMapper;
  spikeMapper->SetInputConnection(glyph->GetOutputPort());
  vtkNew<vtkActor> spikeActor;
  spikeActor->SetMapper(spikeMapper);
  vtkNew<vtkActor> spikeActor2;
  spikeActor2->SetMapper(spikeMapper);

  spikeActor->SetPosition(0, 0.7, 0);
  sphereActor->SetPosition(0, 0.7, 0);
  spikeActor2->SetPosition(0, -1.0, -10);
  sphereActor2->SetPosition(0, -1.0, -10);
  spikeActor2->SetScale(1.5, 1.5, 1.5);
  sphereActor2->SetScale(1.5, 1.5, 1.5);

  ren1->AddActor(sphereActor);
  ren1->AddActor(spikeActor);
  ren1->AddActor(sphereActor2);
  ren1->AddActor(spikeActor2);
  ren1->SetBackground(colors->GetColor3d("Bkg").GetData());
  renWin->SetSize(300, 300);
  renWin->SetWindowName("CameraBlur");
  //   renWin->DoubleBufferOff();

  // Do the first render and then zoom in a little.
  renWin->Render();
  ren1->GetActiveCamera()->SetFocalPoint(0, 0, 0.0);
  ren1->GetActiveCamera()->Zoom(1.8);
  ren1->GetActiveCamera()->SetFocalDisk(0.05);

  renWin->Render();

  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(CameraBlur)

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

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

Download and Build CameraBlur

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

cd CameraBlur/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:

./CameraBlur

WINDOWS USERS

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