Vol

VTKExamples/Cxx/StructuredPoints/Vol


Description

Creating a image data dataset. Scalar data is generated from the equation for a sphere. Volume dimensions are 26^3.

Other Languages

See (Python), (Java)

Question

If you have a simple question about this example contact us at VTKExamplesProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum

Code

Vol.cxx

#include <vtkActor.h>
#include <vtkContourFilter.h>
#include <vtkDoubleArray.h>
#include <vtkNamedColors.h>
#include <vtkPointData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkStructuredPoints.h>

int main(int, char*[])
{
  auto colors =
    vtkSmartPointer<vtkNamedColors>::New();

  auto renderer =
    vtkSmartPointer<vtkRenderer>::New();
  auto renWin =
    vtkSmartPointer<vtkRenderWindow>::New();
  renWin->AddRenderer(renderer);
  auto iren =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  iren->SetRenderWindow(renWin);

  auto vol =
    vtkSmartPointer<vtkStructuredPoints>::New();
  vol->SetDimensions(26, 26, 26);
  vol->SetOrigin(-0.5, -0.5, -0.5);
  auto sp = 1.0 / 25.0;
  vol->SetSpacing(sp, sp, sp);

  auto scalars =
    vtkSmartPointer<vtkDoubleArray>::New();
  scalars->SetNumberOfComponents(1);
  scalars->SetNumberOfTuples(26 * 26 * 26);
  for (auto k = 0; k < 26; k++)
  {
    auto z = -0.5 + k * sp;
    auto kOffset = k * 26 * 26;
    for (auto j = 0; j < 26; j++)
    {
      auto y = -0.5 + j * sp;
      auto jOffset = j * 26;
      for (auto i = 0; i < 26; i++)
      {
        auto x = -0.5 + i * sp;
        auto s = x * x + y * y + z * z - (0.4 * 0.4);
        auto offset = i + jOffset + kOffset;
        scalars->InsertTuple(offset, &s);
      }
    }
  }
  vol->GetPointData()->SetScalars(scalars);

  auto contour =
    vtkSmartPointer<vtkContourFilter>::New();
  contour->SetInputData(vol);
  contour->SetValue(0, 0.0);

  auto volMapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  volMapper->SetInputConnection(contour->GetOutputPort());
  volMapper->ScalarVisibilityOff();
  auto volActor =
    vtkSmartPointer<vtkActor>::New();
  volActor->SetMapper(volMapper);
  volActor->GetProperty()->EdgeVisibilityOn();
  volActor->GetProperty()->SetColor(colors->GetColor3d("Salmon").GetData());
  renderer->AddActor(volActor);
  renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());
  renWin->SetSize(512, 512);

  // interact with data
  renWin->Render();

  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(Vol)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersCore
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping Vol: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(Vol MACOSX_BUNDLE Vol.cxx )
  target_link_libraries(Vol PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(Vol MACOSX_BUNDLE Vol.cxx )
  target_link_libraries(Vol PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS Vol
    MODULES ${VTK_LIBRARIES}
    )
endif () 

Download and Build Vol

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

cd Vol/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:

./Vol

WINDOWS USERS

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