MinimalQtVTKApp

#include <QVTKOpenGLNativeWidget.h>
#include <vtkActor.h>
#include <vtkDataSetMapper.h>
#include <vtkDoubleArray.h>
#include <vtkGenericOpenGLRenderWindow.h>
#include <vtkPointData.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

#include <QApplication>
#include <QDockWidget>
#include <QGridLayout>
#include <QLabel>
#include <QMainWindow>
#include <QPointer>
#include <QPushButton>
#include <QVBoxLayout>

#include <cmath>
#include <cstdlib>
#include <random>

namespace {
/**
 * Deform the sphere source using a random amplitude and modes and render it in
 * the window
 *
 * @param sphere the original sphere source
 * @param mapper the mapper for the scene
 * @param window the window to render to
 * @param randEng the random number generator engine
 */
void Randomize(vtkSphereSource* sphere, vtkMapper* mapper,
               vtkGenericOpenGLRenderWindow* window, std::mt19937& randEng);
} // namespace

int main(int argc, char* argv[])
{
  QSurfaceFormat::setDefaultFormat(QVTKOpenGLNativeWidget::defaultFormat());

  QApplication app(argc, argv);

  // Main window.
  QMainWindow mainWindow;
  mainWindow.resize(1200, 900);

  // Control area.
  QDockWidget controlDock;
  mainWindow.addDockWidget(Qt::LeftDockWidgetArea, &controlDock);

  QLabel controlDockTitle("Control Dock");
  controlDockTitle.setMargin(20);
  controlDock.setTitleBarWidget(&controlDockTitle);

  QPointer<QVBoxLayout> dockLayout = new QVBoxLayout();
  QWidget layoutContainer;
  layoutContainer.setLayout(dockLayout);
  controlDock.setWidget(&layoutContainer);

  QPushButton randomizeButton;
  randomizeButton.setText("Randomize");
  dockLayout->addWidget(&randomizeButton);

  // Render area.
  QPointer<QVTKOpenGLNativeWidget> vtkRenderWidget =
      new QVTKOpenGLNativeWidget();
  mainWindow.setCentralWidget(vtkRenderWidget);

  // VTK part.
  vtkNew<vtkGenericOpenGLRenderWindow> window;
  vtkRenderWidget->setRenderWindow(window.Get());

  vtkNew<vtkSphereSource> sphere;
  sphere->SetRadius(1.0);
  sphere->SetThetaResolution(100);
  sphere->SetPhiResolution(100);

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

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetEdgeVisibility(true);
  actor->GetProperty()->SetRepresentationToSurface();

  vtkNew<vtkRenderer> renderer;
  renderer->AddActor(actor);

  window->AddRenderer(renderer);

  // Setup initial status.
  std::mt19937 randEng(0);
  ::Randomize(sphere, mapper, window, randEng);

  // connect the buttons
  QObject::connect(&randomizeButton, &QPushButton::released,
                   [&]() { ::Randomize(sphere, mapper, window, randEng); });

  mainWindow.show();

  return app.exec();
}

namespace {
void Randomize(vtkSphereSource* sphere, vtkMapper* mapper,
               vtkGenericOpenGLRenderWindow* window, std::mt19937& randEng)
{
  // Generate randomness.
  double randAmp = 0.2 + ((randEng() % 1000) / 1000.0) * 0.2;
  double randThetaFreq = 1.0 + (randEng() % 9);
  double randPhiFreq = 1.0 + (randEng() % 9);

  // Extract and prepare data.
  sphere->Update();
  vtkSmartPointer<vtkPolyData> newSphere;
  newSphere.TakeReference(sphere->GetOutput()->NewInstance());
  newSphere->DeepCopy(sphere->GetOutput());
  vtkNew<vtkDoubleArray> height;
  height->SetName("Height");
  height->SetNumberOfComponents(1);
  height->SetNumberOfTuples(newSphere->GetNumberOfPoints());
  newSphere->GetPointData()->AddArray(height);

  // Deform the sphere.
  for (int iP = 0; iP < newSphere->GetNumberOfPoints(); iP++)
  {
    double pt[3] = {0.0};
    newSphere->GetPoint(iP, pt);
    double theta = std::atan2(pt[1], pt[0]);
    double phi =
        std::atan2(pt[2], std::sqrt(std::pow(pt[0], 2) + std::pow(pt[1], 2)));
    double thisAmp =
        randAmp * std::cos(randThetaFreq * theta) * std::sin(randPhiFreq * phi);
    height->SetValue(iP, thisAmp);
    pt[0] += thisAmp * std::cos(theta) * std::cos(phi);
    pt[1] += thisAmp * std::sin(theta) * std::cos(phi);
    pt[2] += thisAmp * std::sin(phi);
    newSphere->GetPoints()->SetPoint(iP, pt);
  }
  newSphere->GetPointData()->SetScalars(height);

  // Reconfigure the pipeline to take the new deformed sphere.
  mapper->SetInputDataObject(newSphere);
  mapper->SetScalarModeToUsePointData();
  mapper->ColorByArrayComponent("Height", 0);
  window->Render();
}
} // namespace

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

if(POLICY CMP0020)
  cmake_policy(SET CMP0020 NEW)
  cmake_policy(SET CMP0071 NEW)
endif()

PROJECT(MinimalQtVTKApp)

find_package(VTK COMPONENTS 
  GUISupportQt
  RenderingQt
)

if(NOT VTK_FOUND)
  message(FATAL_ERROR "MinimalQtVTKApp: Unable to find the VTK build folder.")
endif()

if(NOT(TARGET VTK::GUISupportQt))
  message(FATAL_ERROR "MinimalQtVTKApp: VTK not built with Qt support.")
endif()

if(NOT DEFINED VTK_QT_VERSION)
  set(VTK_QT_VERSION 5)
endif()

set(qt_components Core Gui Widgets)
if(${VTK_QT_VERSION} VERSION_GREATER_EQUAL 6)
  list(APPEND qt_components OpenGLWidgets)
endif()
list(SORT qt_components)
# We have ui files, so this will also bring in the macro:
#   qt5_wrap_ui or qt_wrap_ui from Widgets.
find_package(Qt${VTK_QT_VERSION} QUIET
  REQUIRED COMPONENTS ${qt_components}
)

foreach(_qt_comp IN LISTS qt_components)
  list(APPEND qt_modules "Qt${VTK_QT_VERSION}::${_qt_comp}")
endforeach()

message (STATUS "VTK_VERSION: ${VTK_VERSION}, Qt Version: ${Qt${VTK_QT_VERSION}Widgets_VERSION}")

# Instruct CMake to run moc and uic automatically when needed.
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTOUIC ON)

include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR})

file(GLOB UI_FILES *.ui)
file(GLOB QT_WRAP *.h)
file(GLOB CXX_FILES *.cxx)

# For VTK versions greater than or equal to 8.90.0:
#  CMAKE_AUTOUIC is ON so we handle uic automatically for Qt targets.
#  CMAKE_AUTOMOC is ON so we handle moc automatically for Qt targets.

# 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.")
# CMAKE_AUTOMOC in ON so the MOC headers will be automatically wrapped.
add_executable(MinimalQtVTKApp MACOSX_BUNDLE
  ${CXX_FILES} ${UISrcs} ${QT_WRAP}
)
if (Qt${VTK_QT_VERSION}Widgets_VERSION VERSION_LESS "5.11.0")
  qt5_use_modules(MinimalQtVTKApp ${qt_components})
else()
  target_link_libraries(MinimalQtVTKApp ${qt_modules})
endif()
target_link_libraries(MinimalQtVTKApp ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS MinimalQtVTKApp
  MODULES ${VTK_LIBRARIES}
)

 cd MinimalQtVTKApp/build

 cmake ..

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

cmake -DQT_QMAKE_EXECUTABLE:FILEPATH=/usr/something/qmake  ..

make

./MinimalQtVTKApp