ColorCells
VTKExamples/Cxx/PolyData/ColorCells
Description
This example shows how to assign specific colors to individual cells of a polydata.
Code
ColorCells.cxx
#include <vtkSmartPointer.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkLookupTable.h>
#include <vtkFloatArray.h>
#include <vtkCellData.h>
#include <vtkPolyData.h>
#include <vtkPlaneSource.h>
#include <algorithm>
int main(int , char *[])
{
// Provide some geometry
int resolution = 3;
vtkSmartPointer<vtkPlaneSource> aPlane =
vtkSmartPointer<vtkPlaneSource>::New();
aPlane->SetXResolution(resolution);
aPlane->SetYResolution(resolution);
// Create cell data
vtkSmartPointer<vtkFloatArray> cellData =
vtkSmartPointer<vtkFloatArray>::New();
for (int i = 0; i < resolution * resolution; i++)
{
cellData->InsertNextValue(i + 1);
}
// Create a lookup table to map cell data to colors
vtkSmartPointer<vtkLookupTable> lut =
vtkSmartPointer<vtkLookupTable>::New();
int tableSize = std::max(resolution*resolution + 1, 10);
lut->SetNumberOfTableValues(tableSize);
lut->Build();
// Fill in a few known colors, the rest will be generated if needed
lut->SetTableValue(0 , 0 , 0 , 0, 1); //Black
lut->SetTableValue(1, 0.8900, 0.8100, 0.3400, 1); // Banana
lut->SetTableValue(2, 1.0000, 0.3882, 0.2784, 1); // Tomato
lut->SetTableValue(3, 0.9608, 0.8706, 0.7020, 1); // Wheat
lut->SetTableValue(4, 0.9020, 0.9020, 0.9804, 1); // Lavender
lut->SetTableValue(5, 1.0000, 0.4900, 0.2500, 1); // Flesh
lut->SetTableValue(6, 0.5300, 0.1500, 0.3400, 1); // Raspberry
lut->SetTableValue(7, 0.9804, 0.5020, 0.4471, 1); // Salmon
lut->SetTableValue(8, 0.7400, 0.9900, 0.7900, 1); // Mint
lut->SetTableValue(9, 0.2000, 0.6300, 0.7900, 1); // Peacock
aPlane->Update(); // Force an update so we can set cell data
aPlane->GetOutput()->GetCellData()->SetScalars(cellData);
// Setup actor and mapper
vtkSmartPointer<vtkPolyDataMapper> mapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(aPlane->GetOutputPort());
mapper->SetScalarRange(0, tableSize - 1);
mapper->SetLookupTable(lut);
vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
// Setup render window, renderer, and interactor
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);
renderer->SetBackground(.1,.2,.3);
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(ColorCells)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(ColorCells MACOSX_BUNDLE ColorCells.cxx)
target_link_libraries(ColorCells ${VTK_LIBRARIES})
Download and Build ColorCells
Click here to download ColorCells and its CMakeLists.txt file. Once the tarball ColorCells.tar has been downloaded and extracted,
cd ColorCells/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:
./ColorCells
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.