TriangleColoredPoints
VTKExamples/Cxx/PolyData/TriangleColoredPoints
Description¶
This example shows how by adding a color to each vertex of a triangle, the triangle's color will be smoothly varying between the colors of the vertices.
Code¶
TriangleColoredPoints.cxx
#include <vtkVersion.h> #include <vtkSmartPointer.h> #include <vtkPoints.h> #include <vtkXMLPolyDataWriter.h> #include <vtkPolyData.h> #include <vtkPointData.h> #include <vtkCellArray.h> #include <vtkTriangle.h> #include <vtkPolyDataMapper.h> #include <vtkActor.h> #include <vtkRenderWindow.h> #include <vtkRenderer.h> #include <vtkRenderWindowInteractor.h> // For compatibility with new VTK generic data arrays #ifdef vtkGenericDataArray_h #define InsertNextTupleValue InsertNextTypedTuple #endif int main(int, char *[]) { // Setup points vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); points->InsertNextPoint(1.0, 0.0, 0.0); points->InsertNextPoint(0.0, 0.0, 0.0); points->InsertNextPoint(0.0, 1.0, 0.0); // Define some colors unsigned char red[3] = {255, 0, 0}; unsigned char green[3] = {0, 255, 0}; unsigned char blue[3] = {0, 0, 255}; // Setup the colors array vtkSmartPointer<vtkUnsignedCharArray> colors = vtkSmartPointer<vtkUnsignedCharArray>::New(); colors->SetNumberOfComponents(3); colors->SetName("Colors"); // Add the three colors we have created to the array colors->InsertNextTupleValue(red); colors->InsertNextTupleValue(green); colors->InsertNextTupleValue(blue); // Create a triangle vtkSmartPointer<vtkCellArray> triangles = vtkSmartPointer<vtkCellArray>::New(); vtkSmartPointer<vtkTriangle> triangle = vtkSmartPointer<vtkTriangle>::New(); triangle->GetPointIds()->SetId(0, 0); triangle->GetPointIds()->SetId(1, 1); triangle->GetPointIds()->SetId(2, 2); triangles->InsertNextCell(triangle); // Create a polydata object and add everything to it vtkSmartPointer<vtkPolyData> polydata = vtkSmartPointer<vtkPolyData>::New(); polydata->SetPoints(points); polydata->SetPolys(triangles); polydata->GetPointData()->SetScalars(colors); // Visualize vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New(); #if VTK_MAJOR_VERSION <= 5 mapper->SetInputConnection(polydata->GetProducerPort()); #else mapper->SetInputData(polydata); #endif vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New(); actor->SetMapper(mapper); 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(actor); renderWindow->Render(); renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(TriangleColoredPoints) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(TriangleColoredPoints MACOSX_BUNDLE TriangleColoredPoints.cxx) target_link_libraries(TriangleColoredPoints ${VTK_LIBRARIES})
Download and Build TriangleColoredPoints¶
Danger
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Click here to download TriangleColoredPoints and its CMakeLists.txt file. Once the tarball TriangleColoredPoints.tar has been downloaded and extracted,
cd TriangleColoredPoints/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:
./TriangleColoredPoints
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.