LoopShrink

vtk-examples/Cxx/Visualization/LoopShrink

Description¶

A network with a loop. VTK 5.0 and later do not allow you to execute a looping visualization network; this was possible in previous versions of VTK.

Info

See Figure 4-22 in Chapter 4 the VTK Textbook.

Other languages

See (Python), (Java)

Question

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

Code¶

LoopShrink.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkCullerCollection.h>
#include <vtkDataSetMapper.h>
#include <vtkElevationFilter.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkShrinkFilter.h>
#include <vtkSphereSource.h>

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

  vtkNew<vtkRenderer> renderer;
  renderer->GetCullers()->RemoveAllItems();

  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(renderer);
  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  vtkNew<vtkSphereSource> sphere;
  sphere->SetThetaResolution(12);
  sphere->SetPhiResolution(12);

  vtkNew<vtkShrinkFilter> shrink;
  shrink->SetInputConnection(sphere->GetOutputPort());
  shrink->SetShrinkFactor(0.9);

  vtkNew<vtkElevationFilter> colorIt;
  colorIt->SetInputConnection(shrink->GetOutputPort());
  colorIt->SetLowPoint(0, 0, -.5);
  colorIt->SetHighPoint(0, 0, .5);

  vtkNew<vtkDataSetMapper> mapper;
  mapper->SetInputConnection(colorIt->GetOutputPort());

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);

  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("LavenderBlush").GetData());
  renWin->SetSize(600, 600);
  renWin->SetWindowName("LoopShrink");

  renWin->Render();

  renderer->GetActiveCamera()->Zoom(1.5);

  // Interact with the data.
  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(LoopShrink)

find_package(VTK COMPONENTS 
)

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

Download and Build LoopShrink¶

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

cd LoopShrink/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:

./LoopShrink

WINDOWS USERS

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