GoldenBallSource

Description¶

A vtkGoldenBallSource algorithm has been added to provide a method to construct a solid, tetrahedralized ball. It uses a Fibonacci spiral (generated using the “Golden Angle” of 180(√5 - 3)°) which is then projected out of the plane onto a sphere and Delaunay-tetrahedralized into a ball. It includes a “normal” vector field by default which is zero-length at the center of the ball.

Besides the spiral construction this algorithm is also distinct from the existing sphere source because it produces a solid rather than a bounding surface.

Other languages

See (PythonicAPI)

Question

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

Code¶

GoldenBallSource.cxx

#include <vtkActor.h>
#include <vtkCameraOrientationWidget.h>
#include <vtkDataSetMapper.h>
#include <vtkGoldenBallSource.h>
#include <vtkInteractorStyleSwitch.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

#include <array>

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;
  colors->SetColor("ParaViewBkg",
                   std::array<unsigned char, 4>{82, 87, 110, 255}.data());

  // Create a golden ball source.
  vtkNew<vtkGoldenBallSource> goldenBallSource;
  goldenBallSource->SetCenter(0.0, 0.0, 0.0);
  goldenBallSource->SetRadius(5.0);
  goldenBallSource->SetResolution(200);
  goldenBallSource->GenerateNormalsOn();
  goldenBallSource->IncludeCenterPointOn();

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

  vtkNew<vtkProperty> actorProp;
  actorProp->SetColor(colors->GetColor3d("Gold").GetData());
  actorProp->SetEdgeColor(colors->GetColor3d("DarkSlateBlue").GetData());
  actorProp->EdgeVisibilityOn();

  vtkNew<vtkActor> actor;
  actor->SetProperty(actorProp);
  actor->SetMapper(mapper);
  actor->GetProperty()->SetColor(colors->GetColor3d("Gold").GetData());

  vtkNew<vtkRenderer> renderer;
  renderer->SetBackground(colors->GetColor3d("ParaViewBkg").GetData());
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->SetSize(600, 600);
  renderWindow->SetWindowName("GoldenBallSource");
  renderWindow->AddRenderer(renderer);
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);
  auto is = vtkInteractorStyleSwitch::SafeDownCast(
      renderWindowInteractor->GetInteractorStyle());
  if (is)
  {
    is->SetCurrentStyleToTrackballCamera();
  }

  renderer->AddActor(actor);

  vtkNew<vtkCameraOrientationWidget> cow;
  cow->SetParentRenderer(renderer);
  // Enable the widget.
  cow->On();

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

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(GoldenBallSource)

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

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

Download and Build GoldenBallSource¶

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

cd GoldenBallSource/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:

./GoldenBallSource

WINDOWS USERS

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