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Point

vtk-examples/Cxx/GeometricObjects/Point


Description

vtkPoints object represents 3D points. The data model for vtkPoints is an array of vx-vy-vz triplets accessible by (point or cell) id.

Other languages

See (Python), (CSharp)

Question

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

Code

Point.cxx

#include <vtkActor.h>
#include <vtkCellArray.h>
#include <vtkNamedColors.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkNew.h>

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

  // Create the geometry of a point (the coordinate)
  vtkNew<vtkPoints> points;
  const float p[3] = {1.0, 2.0, 3.0};

  // Create the topology of the point (a vertex)
  vtkNew<vtkCellArray> vertices;
  // We need an an array of point id's for InsertNextCell.
  vtkIdType pid[1];
  pid[0] = points->InsertNextPoint(p);
  vertices->InsertNextCell(1, pid);

  // Create a polydata object
  vtkNew<vtkPolyData> point;

  // Set the points and vertices we created as the geometry and topology of the
  // polydata
  point->SetPoints(points);
  point->SetVerts(vertices);

  // Visualize
  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputData(point);

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetColor(colors->GetColor3d("Tomato").GetData());
  actor->GetProperty()->SetPointSize(20);

  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->SetWindowName("Point");
  renderWindow->AddRenderer(renderer);
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("DarkGreen").GetData());

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

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(Point)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping Point: ${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(Point MACOSX_BUNDLE Point.cxx )
  target_link_libraries(Point PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(Point MACOSX_BUNDLE Point.cxx )
  target_link_libraries(Point PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS Point
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build Point

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

cd Point/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:

./Point

WINDOWS USERS

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