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Tutorial Step5

vtk-examples/Cxx/Tutorial/Tutorial_Step5


Description

This example introduces the concepts of interaction into the Python environment. A different interaction style (than the default) is defined.

Other languages

See (Python)

Question

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

Code

Tutorial_Step5.cxx

/*=========================================================================

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

// First include the required header files for the VTK classes we are using.
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkConeSource.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

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

  //
  // Next we create an instance of vtkConeSource and set some of its
  // properties. The instance of vtkConeSource "cone" is part of a
  // visualization pipeline (it is a source process object); it produces data
  // (output type is vtkPolyData) which other filters may process.
  //
  vtkNew<vtkConeSource> cone;
  cone->SetHeight(3.0);
  cone->SetRadius(1.0);
  cone->SetResolution(10);

  //
  // In this example we terminate the pipeline with a mapper process object.
  // (Intermediate filters such as vtkShrinkPolyData could be inserted in
  // between the source and the mapper.)  We create an instance of
  // vtkPolyDataMapper to map the polygonal data into graphics primitives. We
  // connect the output of the cone source to the input of this mapper.
  //
  vtkNew<vtkPolyDataMapper> coneMapper;
  coneMapper->SetInputConnection(cone->GetOutputPort());

  //
  // Create an actor to represent the cone. The actor orchestrates rendering
  // of the mapper's graphics primitives. An actor also refers to properties
  // via a vtkProperty instance, and includes an internal transformation
  // matrix. We set this actor's mapper to be coneMapper which we created
  // above.
  //
  vtkNew<vtkActor> coneActor;
  coneActor->SetMapper(coneMapper);
  coneActor->GetProperty()->SetColor(colors->GetColor3d("Bisque").GetData());

  //
  // Create the Renderer and assign actors to it. A renderer is like a
  // viewport. It is part or all of a window on the screen and it is
  // responsible for drawing the actors it has.  We also set the background
  // color here.
  //
  vtkNew<vtkRenderer> ren1;
  ren1->AddActor(coneActor);
  ren1->SetBackground(colors->GetColor3d("MidnightBlue").GetData());

  //
  // Finally we create the render window which will show up on the screen.
  // We put our renderer into the render window using AddRenderer. We also
  // set the size to be 300 pixels by 300.
  //
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(ren1);
  renWin->SetSize(300, 300);
  renWin->SetWindowName("Tutorial_Step5");

  //
  // The vtkRenderWindowInteractor class watches for events (e.g., keypress,
  // mouse) in the vtkRenderWindow. These events are translated into
  // event invocations that VTK understands (see VTK/Common/vtkCommand.h
  // for all events that VTK processes). Then observers of these VTK
  // events can process them as appropriate.
  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  //
  // By default the vtkRenderWindowInteractor instantiates an instance
  // of vtkInteractorStyle. vtkInteractorStyle translates a set of events
  // it observes into operations on the camera, actors, and/or properties
  // in the vtkRenderWindow associated with the vtkRenderWinodwInteractor.
  // Here we specify a particular interactor style.
  vtkNew<vtkInteractorStyleTrackballCamera> style;
  iren->SetInteractorStyle(style);

  //
  // Unlike the previous scripts where we performed some operations and then
  // exited, here we leave an event loop running. The user can use the mouse
  // and keyboard to perform the operations on the scene according to the
  // current interaction style. When the user presses the "e" key, by default
  // an ExitEvent is invoked by the vtkRenderWindowInteractor which is caught
  // and drops out of the event loop (triggered by the Start() method that
  // follows.
  //
  iren->Initialize();
  iren->Start();

  //
  // Final note: recall that observers can watch for particular events and
  // take appropriate action. Pressing "u" in the render window causes the
  // vtkRenderWindowInteractor to invoke a UserEvent. This can be caught to
  // popup a GUI, etc. See the Tcl Cone5.tcl example for an idea of how this
  // works.

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(Tutorial_Step5)

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

if (NOT VTK_FOUND)
  message("Skipping Tutorial_Step5: ${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(Tutorial_Step5 MACOSX_BUNDLE Tutorial_Step5.cxx )
  target_link_libraries(Tutorial_Step5 PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(Tutorial_Step5 MACOSX_BUNDLE Tutorial_Step5.cxx )
  target_link_libraries(Tutorial_Step5 PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS Tutorial_Step5
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build Tutorial_Step5

Click here to download Tutorial_Step5 and its CMakeLists.txt file. Once the tarball Tutorial_Step5.tar has been downloaded and extracted,

cd Tutorial_Step5/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:

./Tutorial_Step5

WINDOWS USERS

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