VTK/Examples/Cxx/Filtering/Delaunay2D
From KitwarePublic
This example generates a set of points aligned with an XY grid with random heights (z values). The Delaunay2D filter "magically" knows how to triangulate this type of point set because it projects the points by default onto the XY axis and then performs a 2D Delaunay triangulation. The result is a mesh on the input points.
Delaunay2D.cxx
#include <vtkVersion.h> #include <vtkCellArray.h> #include <vtkPoints.h> #include <vtkTriangle.h> #include <vtkPolyData.h> #include <vtkPointData.h> #include <vtkLine.h> #include <vtkCellLocator.h> #include <vtkSmartPointer.h> #include <vtkDelaunay2D.h> #include <vtkPolyDataMapper.h> #include <vtkActor.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkProperty.h> #include <vtkVertexGlyphFilter.h> int main(int, char *[]) { // Create a set of heighs on a grid. // This is often called a "terrain map". vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); unsigned int GridSize = 10; for(unsigned int x = 0; x < GridSize; x++) { for(unsigned int y = 0; y < GridSize; y++) { points->InsertNextPoint(x, y, (x+y)/(y+1)); } } // Add the grid points to a polydata object vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New(); polydata->SetPoints(points); // Triangulate the grid points vtkSmartPointer<vtkDelaunay2D> delaunay = vtkSmartPointer<vtkDelaunay2D>::New(); #if VTK_MAJOR_VERSION <= 5 delaunay->SetInput(polydata); #else delaunay->SetInputData(polydata); #endif delaunay->Update(); // Visualize vtkSmartPointer<vtkPolyDataMapper> meshMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); meshMapper->SetInputConnection(delaunay->GetOutputPort()); vtkSmartPointer<vtkActor> meshActor = vtkSmartPointer<vtkActor>::New(); meshActor->SetMapper(meshMapper); vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter = vtkSmartPointer<vtkVertexGlyphFilter>::New(); #if VTK_MAJOR_VERSION <= 5 glyphFilter->SetInputConnection(polydata->GetProducerPort()); #else glyphFilter->SetInputData(polydata); #endif glyphFilter->Update(); vtkSmartPointer<vtkPolyDataMapper> pointMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); pointMapper->SetInputConnection(glyphFilter->GetOutputPort()); vtkSmartPointer<vtkActor> pointActor = vtkSmartPointer<vtkActor>::New(); pointActor->GetProperty()->SetColor(1,0,0); pointActor->GetProperty()->SetPointSize(3); pointActor->SetMapper(pointMapper); vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->AddRenderer(renderer); vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); renderWindowInteractor->SetRenderWindow(renderWindow); renderer->AddActor(meshActor); renderer->AddActor(pointActor); renderer->SetBackground(.3, .6, .3); // Background color green renderWindow->Render(); renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt
cmake_minimum_required(VERSION 2.6) PROJECT(Delaunay) FIND_PACKAGE(VTK REQUIRED) INCLUDE(${VTK_USE_FILE}) ADD_EXECUTABLE(Delaunay Delaunay.cxx) TARGET_LINK_LIBRARIES(Delaunay vtkHybrid)
