VTK/Examples/Cxx/Visualization/BackgroundTexture
From KitwarePublic
Jump to navigationJump to searchContents
BackgroundTexture.cxx
#include <vtkVersion.h>
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkCellArray.h>
#include <vtkColorTransferFunction.h>
#include <vtkContourFilter.h>
#include <vtkFloatArray.h>
#include <vtkPointData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkShepardMethod.h>
#include <vtkSmartPointer.h>
#include <vtkVertexGlyphFilter.h>
// For compatibility with new VTK generic data arrays
#ifdef vtkGenericDataArray_h
#define InsertNextTupleValue InsertNextTypedTuple
#endif
int main(int, char *[])
{
// Create a set of vertices (polydata)
vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint(100.0, 0.0, 0.0);
points->InsertNextPoint(300.0, 0.0, 0.0);
// Setup colors
unsigned char white[3] = {255, 255, 255};
unsigned char black[3] = {0, 0, 0};
vtkSmartPointer<vtkUnsignedCharArray> vertexColors =
vtkSmartPointer<vtkUnsignedCharArray>::New();
vertexColors->SetNumberOfComponents(3);
vertexColors->SetName("Colors");
vertexColors->InsertNextTupleValue(black);
vertexColors->InsertNextTupleValue(white);
// Create a scalar array for the pointdata, each value represents the distance
// of the vertices from the first vertex
vtkSmartPointer<vtkFloatArray> values =
vtkSmartPointer<vtkFloatArray>::New();
values->SetNumberOfComponents(1);
values->SetName("Values");
values->InsertNextValue(0.0);
values->InsertNextValue(1.0);
// We must make two objects, because the ShepardMethod uses the ActiveScalars, as does the renderer!
vtkSmartPointer<vtkPolyData> polydataToProcess =
vtkSmartPointer<vtkPolyData>::New();
polydataToProcess->SetPoints(points);
polydataToProcess->GetPointData()->SetScalars(values);
vtkSmartPointer<vtkPolyData> polydataToVisualize =
vtkSmartPointer<vtkPolyData>::New();
polydataToVisualize->SetPoints(points);
polydataToVisualize->GetPointData()->SetScalars(vertexColors);
vtkSmartPointer<vtkVertexGlyphFilter> vertexGlyphFilter =
vtkSmartPointer<vtkVertexGlyphFilter>::New();
#if VTK_MAJOR_VERSION <= 5
vertexGlyphFilter->AddInputConnection(polydataToVisualize->GetProducerPort());
#else
vertexGlyphFilter->AddInputData(polydataToVisualize);
#endif
vertexGlyphFilter->Update();
//Create a mapper and actor
vtkSmartPointer<vtkPolyDataMapper> vertsMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
//vertsMapper->ScalarVisibilityOff();
vertsMapper->SetInputConnection(vertexGlyphFilter->GetOutputPort());
vtkSmartPointer<vtkActor> vertsActor =
vtkSmartPointer<vtkActor>::New();
vertsActor->SetMapper(vertsMapper);
vertsActor->GetProperty()->SetColor(1,0,0);
vertsActor->GetProperty()->SetPointSize(3);
// Create a shepard filter to interpolate the vertices over a regularized image grid
vtkSmartPointer<vtkShepardMethod> shepard = vtkSmartPointer<vtkShepardMethod>::New();
#if VTK_MAJOR_VERSION <= 5
shepard->SetInputConnection(polydataToProcess->GetProducerPort());
#else
shepard->SetInputData(polydataToProcess);
#endif
shepard->SetSampleDimensions(2,2,2);
shepard->SetModelBounds(100,300,-10,10,-10,10);
shepard->SetMaximumDistance(1);
// Contour the shepard generated image at 3 isovalues
// The accuracy of the results are highly dependent on how the shepard filter is set up
vtkSmartPointer<vtkContourFilter> contourFilter = vtkSmartPointer<vtkContourFilter>::New();
contourFilter->SetNumberOfContours(3);
contourFilter->SetValue(0, 0.25);
contourFilter->SetValue(1, 0.50);
contourFilter->SetValue(2, 0.75);
contourFilter->SetInputConnection(shepard->GetOutputPort());
contourFilter->Update();
//Create a mapper and actor for the resulting isosurfaces
vtkSmartPointer<vtkPolyDataMapper> contourMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
contourMapper->SetInputConnection(contourFilter->GetOutputPort());
contourMapper->ScalarVisibilityOn();
contourMapper->SetColorModeToMapScalars();
vtkSmartPointer<vtkActor> contourActor =
vtkSmartPointer<vtkActor>::New();
contourActor->SetMapper(contourMapper);
contourActor->GetProperty()->SetAmbient(1);
contourActor->GetProperty()->SetSpecular(0);
contourActor->GetProperty()->SetDiffuse(0);
// Report the results of the interpolation
double *range = contourFilter->GetOutput()->GetScalarRange();
std::cout << "Shepard interpolation:" << std::endl;
std::cout << "contour output scalar range: " << range[0] << ", " << range[1] << std::endl;
vtkIdType nCells = contourFilter->GetOutput()->GetNumberOfCells();
double bounds[6];
for( vtkIdType i = 0; i < nCells; ++i )
{
if(i%2) // each isosurface value only has 2 cells to report on the odd ones
{
contourFilter->GetOutput()->GetCellBounds(i,bounds);
std::cout << "cell " << i << ", x position: " << bounds[0] << std::endl;
}
}
// Create a transfer function to color the isosurfaces
vtkSmartPointer<vtkColorTransferFunction> lut =
vtkSmartPointer<vtkColorTransferFunction>::New();
lut->SetColorSpaceToRGB();
lut->AddRGBPoint(range[0],0,0,0);//black
lut->AddRGBPoint(range[1],1,1,1);//white
lut->SetScaleToLinear();
contourMapper->SetLookupTable( lut );
// Create a renderer, render window and interactor
vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
renderer->GradientBackgroundOn();
renderer->SetBackground(0,0,1);
renderer->SetBackground2(1,0,1);
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
renderer->AddActor(contourActor);
renderer->AddActor(vertsActor);
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);
// Position the camera so that the image produced is viewable
vtkCamera* camera = renderer->GetActiveCamera();
camera->SetPosition(450, 100, 100);
camera->SetFocalPoint(200, 0, 0);
camera->SetViewUp(0, 0, 1);
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
Please try the new VTKExamples website.
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(BackgroundTexture)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(BackgroundTexture MACOSX_BUNDLE BackgroundTexture.cxx)
if(VTK_LIBRARIES)
target_link_libraries(BackgroundTexture ${VTK_LIBRARIES})
else()
target_link_libraries(BackgroundTexture vtkHybrid vtkWidgets)
endif()
Download and Build BackgroundTexture
Click here to download BackgroundTexture. and its CMakeLists.txt file.
Once the tarball BackgroundTexture.tar has been downloaded and extracted,
cd BackgroundTexture/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:
./BackgroundTexture
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.