ConeDemo

VTKExamples/Cxx/GeometricObjects/ConeDemo


Description

vtkConeSource object creates a cone centered at a specified point and pointing in a specified direction. (By default, the center is the origin and the direction is the x-axis.)

Depending upon the resolution of this object, different representations are created. If resolution=0 a line is created; if resolution=1, a single triangle is created; if resolution=2, two crossed triangles are created.

For resolution > 2, a 3D cone (with resolution number of sides) is created.

It also is possible to control whether the bottom of the cone is capped with a (resolution-sided) polygon, and to specify the height and radius of the cone.

The example shows cones with resolutions 0, 1, 2, and 3.

Style

This example collects all of the color definition in the beginning of the example. This makes it easier to make changes to the colors without having to search the code.

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

ConeDemo.cxx

#include <vtkSmartPointer.h>
#include <vtkConeSource.h>

#include <vtkCamera.h>
#include <vtkProperty.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleTrackballCamera.h>

#include <vtkNamedColors.h>
#include <vtkColor.h>

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

  // Define all of the colors used in the example
  vtkColor3d backgroundColor    = colors->GetColor3d("tan");
  vtkColor3d actorColor         = colors->GetColor3d("orchid");
  vtkColor3d actorBackfaceColor = colors->GetColor3d("PowderBlue");
  vtkColor3d coneLineColor      = colors->GetColor3d("Black");

  auto renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetSize(640, 480);
  renderWindow->SetWindowName("ConeDemo");

  auto renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Shared camera
  auto camera =
    vtkSmartPointer<vtkCamera>::New();

  // Define viewport ranges
  double xmins[4] = {0,.5,0,.5};
  double xmaxs[4] = {0.5,1,0.5,1};
  double ymins[4] = {0,0,.5,.5};
  double ymaxs[4]= {0.5,0.5,1,1};

  // Each viewport will contain a cone with an increasing resolution
  for(unsigned i = 0; i < 4; i++)
  {
    auto renderer =
      vtkSmartPointer<vtkRenderer>::New();
    renderer->SetBackground(backgroundColor.GetData());

    renderWindow->AddRenderer(renderer);
    renderer->SetViewport(xmins[i],ymins[i],xmaxs[i],ymaxs[i]);

    // Create a cone with different resolutions
    auto coneSource =
      vtkSmartPointer<vtkConeSource>::New();
    coneSource->SetResolution(i);
    coneSource->SetDirection(0, 1, 0);
    if (i == 3)
    {
      coneSource->SetResolution(20);
    }

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

    auto backfaceProp =
      vtkSmartPointer<vtkProperty>::New();
    backfaceProp->SetDiffuseColor(actorBackfaceColor.GetData());

    auto actor = vtkSmartPointer<vtkActor>::New();
    actor->SetMapper(mapper);
    if (i > 0)
    {
      actor->GetProperty()->
        SetDiffuseColor(actorColor.GetData());
    }
    else
    {
      actor->GetProperty()->
        SetDiffuseColor(coneLineColor.GetData());
    }
    actor->GetProperty()->SetLineWidth(2);
    actor->GetProperty()->EdgeVisibilityOn();
    actor->SetBackfaceProperty(backfaceProp);
    renderer->AddActor(actor);
    renderer->SetActiveCamera(camera);
    if (i == 3)
    {
      renderer->ResetCamera();
    }
  }
  camera->Azimuth(120);
  camera->Elevation(45);
  camera->Dolly(1.1);

  auto style =
    vtkSmartPointer<vtkInteractorStyleTrackballCamera>::New();
  renderWindowInteractor->SetInteractorStyle(style);
  renderWindow->Render();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(ConeDemo)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersSources
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping ConeDemo: ${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(ConeDemo MACOSX_BUNDLE ConeDemo.cxx )
  target_link_libraries(ConeDemo PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(ConeDemo MACOSX_BUNDLE ConeDemo.cxx )
  target_link_libraries(ConeDemo PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS ConeDemo
    MODULES ${VTK_LIBRARIES}
    )
endif () 

Download and Build ConeDemo

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

cd ConeDemo/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:

./ConeDemo

WINDOWS USERS

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