SourceObjectsDemo

Description¶

Examples of source objects that procedurally generate polygonal models. These nine images represent just some of the capability of VTK. From upper left in reading order: sphere, cone, cylinder, cube, plane, text, random point cloud, disk (with or without hole), and line source.

Info

See Figure 3-26 in Chapter 3 the VTK Textbook.

Other languages

See (Python), (PythonicAPI)

Question

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

Code¶

SourceObjectsDemo.cxx

#include <vtkActor.h>
#include <vtkActor2D.h>
#include <vtkCamera.h>
#include <vtkConeSource.h>
#include <vtkCubeSource.h>
#include <vtkCylinderSource.h>
#include <vtkDiskSource.h>
#include <vtkLineSource.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPlaneSource.h>
#include <vtkPointSource.h>
#include <vtkPoints.h>
#include <vtkPolyDataAlgorithm.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkTextMapper.h>
#include <vtkTextProperty.h>
#include <vtkTextSource.h>

#include <array>
#include <vector>

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

  // Set the background color.
  std::array<unsigned char, 4> bkg{{51, 77, 102, 255}};
  colors->SetColor("BkgColor", bkg.data());

  std::vector<vtkSmartPointer<vtkPolyDataAlgorithm>> sourceObjects;
  sourceObjects.push_back(vtkSmartPointer<vtkSphereSource>::New());
  static_cast<vtkSphereSource*>(sourceObjects.back().GetPointer())
      ->SetPhiResolution(21);
  static_cast<vtkSphereSource*>(sourceObjects.back().GetPointer())
      ->SetThetaResolution(21);

  sourceObjects.push_back(vtkSmartPointer<vtkConeSource>::New());
  static_cast<vtkConeSource*>(sourceObjects.back().GetPointer())
      ->SetResolution(51);

  sourceObjects.push_back(vtkSmartPointer<vtkCylinderSource>::New());
  static_cast<vtkCylinderSource*>(sourceObjects.back().GetPointer())
      ->SetResolution(51);

  sourceObjects.push_back(vtkSmartPointer<vtkCubeSource>::New());
  sourceObjects.push_back(vtkSmartPointer<vtkPlaneSource>::New());
  sourceObjects.push_back(vtkSmartPointer<vtkTextSource>::New());
  static_cast<vtkTextSource*>(sourceObjects.back().GetPointer())
      ->SetText("Hello");
  static_cast<vtkTextSource*>(sourceObjects.back().GetPointer())->BackingOff();

  sourceObjects.push_back(vtkSmartPointer<vtkPointSource>::New());
  static_cast<vtkPointSource*>(sourceObjects.back().GetPointer())
      ->SetNumberOfPoints(500);

  sourceObjects.push_back(vtkSmartPointer<vtkDiskSource>::New());
  static_cast<vtkDiskSource*>(sourceObjects.back().GetPointer())
      ->SetCircumferentialResolution(51);

  sourceObjects.push_back(vtkSmartPointer<vtkLineSource>::New());

  std::vector<vtkSmartPointer<vtkRenderer>> renderers;
  std::vector<vtkSmartPointer<vtkPolyDataMapper>> mappers;
  std::vector<vtkSmartPointer<vtkActor>> actors;
  std::vector<vtkSmartPointer<vtkTextMapper>> textmappers;
  std::vector<vtkSmartPointer<vtkActor2D>> textactors;

  // Create one text property for all
  vtkNew<vtkTextProperty> textProperty;
  textProperty->SetFontSize(16);
  textProperty->SetJustificationToCentered();
  textProperty->SetColor(colors->GetColor3d("LightGoldenrodYellow").GetData());

  vtkNew<vtkProperty> backProperty;
  backProperty->SetColor(colors->GetColor3d("Tomato").GetData());

  // Create a source, renderer, mapper, and actor
  // for each object
  for (unsigned int i = 0; i < sourceObjects.size(); i++)
  {
    mappers.push_back(vtkSmartPointer<vtkPolyDataMapper>::New());
    mappers[i]->SetInputConnection(sourceObjects[i]->GetOutputPort());

    actors.push_back(vtkSmartPointer<vtkActor>::New());
    actors[i]->SetMapper(mappers[i]);
    actors[i]->GetProperty()->SetColor(
        colors->GetColor3d("PeachPuff").GetData());
    actors[i]->SetBackfaceProperty(backProperty);

    textmappers.push_back(vtkSmartPointer<vtkTextMapper>::New());
    textmappers[i]->SetInput(sourceObjects[i]->GetClassName());
    textmappers[i]->SetTextProperty(textProperty);

    textactors.push_back(vtkSmartPointer<vtkActor2D>::New());
    textactors[i]->SetMapper(textmappers[i]);
    textactors[i]->SetPosition(120, 16);
    renderers.push_back(vtkSmartPointer<vtkRenderer>::New());
  }

  auto gridDimensions = 3;

  // // Need a renderer even if there is no actor
  // for (auto i = static_cast<int>(sourceObjects.size());
  //      i < gridDimensions * gridDimensions; ++i)
  // {
  //   renderers.push_back(vtkSmartPointer<vtkRenderer>::New());
  // }

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->SetWindowName("SourceObjectsDemo");

  int rendererSize = 300;
  renderWindow->SetSize(rendererSize * gridDimensions,
                        rendererSize * gridDimensions);

  for (auto row = 0; row < gridDimensions; row++)
  {
    for (auto col = 0; col < gridDimensions; col++)
    {
      auto index = row * gridDimensions + col;
      auto x0 = double(col) / gridDimensions;
      auto y0 = double(gridDimensions - row - 1) / gridDimensions;
      auto x1 = double(col + 1) / gridDimensions;
      auto y1 = double(gridDimensions - row) / gridDimensions;
      renderWindow->AddRenderer(renderers[index]);
      renderers[index]->SetViewport(x0, y0, x1, y1);

      if (index > static_cast<int>(sourceObjects.size() - 1))
      {
        continue;
      }

      renderers[index]->AddActor(actors[index]);
      renderers[index]->AddActor(textactors[index]);
      renderers[index]->SetBackground(colors->GetColor3d("BkgColor").GetData());
      renderers[index]->ResetCamera();
      renderers[index]->GetActiveCamera()->Azimuth(30);
      renderers[index]->GetActiveCamera()->Elevation(30);
      renderers[index]->GetActiveCamera()->Zoom(0.8);
      renderers[index]->ResetCameraClippingRange();
    }
  }

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

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

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(SourceObjectsDemo)

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

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

Download and Build SourceObjectsDemo¶

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

cd SourceObjectsDemo/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:

./SourceObjectsDemo

WINDOWS USERS

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