Point

VTKExamples/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 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

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 <vtkSmartPointer.h>

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

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

  // Create the topology of the point (a vertex)
  vtkSmartPointer<vtkCellArray> vertices =
    vtkSmartPointer<vtkCellArray>::New();
  // 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
  vtkSmartPointer<vtkPolyData> point =
    vtkSmartPointer<vtkPolyData>::New();

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

  // Visualize
  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputData(point);

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

  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetWindowName("Point");
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = 
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("DarkOliveGreen").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
  vtkRenderingCore
  vtkRenderingFreeType
  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.