ExtractPointsDemo
VTKEx/Cxx/Points/ExtractPointsDemo
Description¶
Demonstrates point extraction from four implicit functions: sphere, cone, cylinder and superquadric.
Warning
The classes used in this example require vtk 7.1 or later.
Question
If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum
Code¶
ExtractPointsDemo.cxx
#include <vtkBoundedPointSource.h>
#include <vtkCamera.h>
#include <vtkCone.h>
#include <vtkCylinder.h>
#include <vtkExtractPoints.h>
#include <vtkGlyph3DMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkSphere.h>
#include <vtkSphereSource.h>
#include <vtkSuperquadric.h>
#include <vector>
int main(int /*argc*/, char* /* argv */[])
{
// Create implicit functions
auto cone = vtkSmartPointer<vtkCone>::New();
cone->SetAngle(30.0);
auto sphere = vtkSmartPointer<vtkSphere>::New();
auto cylinder = vtkSmartPointer<vtkCylinder>::New();
auto superquadric = vtkSmartPointer<vtkSuperquadric>::New();
superquadric->SetPhiRoundness(2.5);
superquadric->SetThetaRoundness(.5);
// Store the functions
std::vector<vtkSmartPointer<vtkImplicitFunction>> functions;
functions.push_back(sphere);
functions.push_back(cone);
functions.push_back(cylinder);
functions.push_back(superquadric);
auto pointSource = vtkSmartPointer<vtkBoundedPointSource>::New();
pointSource->SetNumberOfPoints(100000);
// Rows and columns
unsigned int gridXDimensions = 2;
unsigned int gridYDimensions = 2;
// Need a renderer even if there is no actor
std::vector<vtkSmartPointer<vtkRenderer>> renderers;
double background[6] = {.4, .5, .6, .6, .5, .4};
for (size_t i = 0; i < gridXDimensions * gridYDimensions; i++)
{
renderers.push_back(vtkSmartPointer<vtkRenderer>::New());
renderers[i]->SetBackground(background);
auto fwdIt = std::rotate(background, background + 1, background + 6);
}
// Glyphs
double radius = .02;
auto sphereSource = vtkSmartPointer<vtkSphereSource>::New();
sphereSource->SetRadius(radius);
// One render window
auto renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
int rendererSize = 256;
renderWindow->SetSize(rendererSize * gridXDimensions,
rendererSize * gridYDimensions);
// Create a pipeline for each function
for (int row = 0; row < static_cast<int>(gridYDimensions); row++)
{
for (int col = 0; col < static_cast<int>(gridXDimensions); col++)
{
int index = row * gridXDimensions + col;
// (xmin, ymin, xmax, ymax)
double viewport[4] = {static_cast<double>(col) * rendererSize /
(gridXDimensions * rendererSize),
static_cast<double>(gridYDimensions - (row + 1)) *
rendererSize / (gridYDimensions * rendererSize),
static_cast<double>(col + 1) * rendererSize /
(gridXDimensions * rendererSize),
static_cast<double>(gridYDimensions - row) *
rendererSize /
(gridYDimensions * rendererSize)};
renderWindow->AddRenderer(renderers[index]);
renderers[index]->SetViewport(viewport);
if (index > static_cast<int>(functions.size() - 1))
{
continue;
}
// Define the pipeline
auto extract = vtkSmartPointer<vtkExtractPoints>::New();
extract->SetInputConnection(pointSource->GetOutputPort());
extract->SetImplicitFunction(functions[index]);
auto glyph = vtkSmartPointer<vtkGlyph3DMapper>::New();
glyph->SetInputConnection(extract->GetOutputPort());
glyph->SetSourceConnection(sphereSource->GetOutputPort());
glyph->ScalingOff();
auto glyphActor = vtkSmartPointer<vtkActor>::New();
glyphActor->SetMapper(glyph);
renderers[index]->AddActor(glyphActor);
renderers[index]->ResetCamera();
renderers[index]->GetActiveCamera()->Azimuth(30);
renderers[index]->GetActiveCamera()->Elevation(-30);
renderers[index]->GetActiveCamera()->Dolly(1.1);
renderers[index]->ResetCameraClippingRange();
}
}
auto iren = vtkSmartPointer<vtkRenderWindowInteractor>::New();
iren->SetRenderWindow(renderWindow);
renderWindow->Render();
iren->Initialize();
iren->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
project(ExtractPointsDemo)
find_package(VTK COMPONENTS
vtkvtkCommonCore
vtkvtkCommonDataModel
vtkvtkFiltersPoints
vtkvtkFiltersSources
vtkvtkInteractionStyle
vtkvtkRenderingContextOpenGL2
vtkvtkRenderingCore
vtkvtkRenderingFreeType
vtkvtkRenderingGL2PSOpenGL2
vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
message("Skipping ExtractPointsDemo: ${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(ExtractPointsDemo MACOSX_BUNDLE ExtractPointsDemo.cxx )
target_link_libraries(ExtractPointsDemo PRIVATE ${VTK_LIBRARIES})
else ()
# include all components
add_executable(ExtractPointsDemo MACOSX_BUNDLE ExtractPointsDemo.cxx )
target_link_libraries(ExtractPointsDemo PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS ExtractPointsDemo
MODULES ${VTK_LIBRARIES}
)
endif ()
Download and Build ExtractPointsDemo¶
Click here to download ExtractPointsDemo and its CMakeLists.txt file. Once the tarball ExtractPointsDemo.tar has been downloaded and extracted,
cd ExtractPointsDemo/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:
./ExtractPointsDemo
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.