WarpScalar

#include <vtkActor.h>
#include <vtkDoubleArray.h>
#include <vtkPointData.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkWarpScalar.h>
#include <vtkMath.h>

int main(int, char *[])
{
  // Create a sphere
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->Update();

  // Create Scalars
  vtkSmartPointer<vtkDoubleArray> scalars =
    vtkSmartPointer<vtkDoubleArray>::New();
  int numberOfPoints = sphereSource->GetOutput()->GetNumberOfPoints();
  scalars->SetNumberOfTuples(numberOfPoints);

  vtkMath::RandomSeed(8775070); // for reproducibility
  for(vtkIdType i = 0; i < numberOfPoints; ++i)
  {
    scalars->SetTuple1(i, vtkMath::Random(0.0, 1.0 / 7.0));
  }

  sphereSource->GetOutput()->GetPointData()->SetScalars(scalars);

  vtkSmartPointer<vtkWarpScalar> warpScalar =
    vtkSmartPointer<vtkWarpScalar>::New();
  warpScalar->SetInputConnection(sphereSource->GetOutputPort());
  warpScalar->SetScaleFactor(1); // use the scalars themselves

  // Required for SetNormal to have an effect
  warpScalar->UseNormalOn();
  warpScalar->SetNormal(0, 0, 1);

  warpScalar->Update();

  // Create a mapper and actor
  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputConnection(warpScalar->GetOutputPort());

  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);

  // Visualize
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  renderer->AddActor(actor);
  renderer->SetBackground(1,1,1); // Background color white

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

  return EXIT_SUCCESS;
}

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(WarpScalar)

find_package(VTK COMPONENTS 
  vtkvtkCommonCore
  vtkvtkCommonDataModel
  vtkvtkFiltersGeneral
  vtkvtkFiltersSources
  vtkvtkInteractionStyle
  vtkvtkRenderingContextOpenGL2
  vtkvtkRenderingCore
  vtkvtkRenderingFreeType
  vtkvtkRenderingGL2PSOpenGL2
  vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping WarpScalar: ${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(WarpScalar MACOSX_BUNDLE WarpScalar.cxx )
  target_link_libraries(WarpScalar PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(WarpScalar MACOSX_BUNDLE WarpScalar.cxx )
  target_link_libraries(WarpScalar PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS WarpScalar
    MODULES ${VTK_LIBRARIES}
    )
endif ()

cd WarpScalar/build

cmake ..

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

make

./WarpScalar