TableBasedClipDataSetWithPolyData2
vtk-examples/Cxx/Meshes/TableBasedClipDataSetWithPolyData2
Description¶
The example that shows how to use the vtkTableBasedClipDataSet to clip a vtkRectilinearGrid that contains a checkerboard pattern.
Question
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Code¶
TableBasedClipDataSetWithPolyData2.cxx
// This program draws a checkerboard ala an OOF3D image display and
// clips it with two planes.
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkCellData.h>
#include <vtkDataSetMapper.h>
#include <vtkDoubleArray.h>
#include <vtkExecutive.h>
#include <vtkImageData.h>
#include <vtkImageMapToColors.h>
#include <vtkInteractorStyleSwitch.h>
#include <vtkLookupTable.h>
#include <vtkMapper.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPlanes.h>
#include <vtkPointData.h>
#include <vtkPoints.h>
#include <vtkProperty.h>
#include <vtkRectilinearGrid.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkTableBasedClipDataSet.h>
///////////////////
namespace {
// Make a rectilinear grid that shows image-like data, by creating a
// cubic cell at each point. A checkerboard pattern is used for
// simplicity.
vtkSmartPointer<vtkRectilinearGrid> makeImage(int n);
} // namespace
int main(int, char*[])
{
constexpr int imageSize = 64; // number of checkerboard squares on a side.
// Offsets for clipping planes with normals in the X and Y directions.
constexpr int xOffset = 8;
constexpr int yOffset = 8;
vtkMapper::SetResolveCoincidentTopologyToPolygonOffset();
vtkNew<vtkNamedColors> colors;
vtkNew<vtkRenderer> renderer;
renderer->SetBackground(colors->GetColor3d("Wheat").GetData());
renderer->UseHiddenLineRemovalOn();
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->AddRenderer(renderer);
renderWindow->SetSize(640, 480);
renderWindow->SetWindowName("TableBasedClipDataSetWithPolyData2");
vtkNew<vtkRenderWindowInteractor> interactor;
vtkNew<vtkInteractorStyleSwitch> style;
interactor->SetInteractorStyle(style);
interactor->SetRenderWindow(renderWindow);
vtkSmartPointer<vtkRectilinearGrid> image = makeImage(imageSize);
// Clipping planes in the X and Y direction.
auto normals = vtkSmartPointer<vtkDoubleArray>::New();
vtkNew<vtkPoints> clipPts;
normals->SetNumberOfComponents(3);
double xnorm[3] = {-1., 0., 0.};
double ynorm[3] = {0., -1., 0.};
double xpt[3] = {xOffset, 0., 0.};
double ypt[3] = {0., yOffset, 0.};
normals->InsertNextTuple(xnorm);
normals->InsertNextTuple(ynorm);
clipPts->InsertNextPoint(xpt);
clipPts->InsertNextPoint(ypt);
vtkNew<vtkPlanes> clipPlanes;
clipPlanes->SetNormals(normals);
clipPlanes->SetPoints(clipPts);
vtkNew<vtkTableBasedClipDataSet> clipper;
clipper->SetClipFunction(clipPlanes);
clipper->SetInputData(image);
vtkNew<vtkDataSetMapper> imageMapper;
vtkNew<vtkActor> imageActor;
imageActor->SetMapper(imageMapper);
renderer->AddViewProp(imageActor);
imageMapper->SetInputConnection(clipper->GetOutputPort());
renderer->ResetCamera();
renderer->GetActiveCamera()->Azimuth(120);
renderer->GetActiveCamera()->Elevation(30);
renderer->ResetCameraClippingRange();
renderWindow->Render();
interactor->Start();
return EXIT_SUCCESS;
}
namespace {
vtkSmartPointer<vtkRectilinearGrid> makeImage(int n)
{
constexpr double cubeSize =
20.0; // physical linear dimension of entire system.
// This is a simplification of a program that uses actual image data
// as a source for the rectilinear grid. In order to recreate the
// same vtk calls, create a dummy image here.
vtkNew<vtkImageData> image0;
image0->SetDimensions(n, n, n);
image0->AllocateScalars(VTK_UNSIGNED_CHAR, 1);
image0->SetSpacing(cubeSize / n, cubeSize / n, cubeSize / n);
int checkerSize = n / 8;
for (int z = 0; z < n; z++)
{
for (int y = 0; y < n; y++)
{
for (int x = 0; x < n; x++)
{
unsigned char* ptr = (unsigned char*)image0->GetScalarPointer(x, y, z);
*ptr = (x / checkerSize + y / checkerSize + z / checkerSize) %
2; // checkerboard
}
}
}
// Color for the checkerboard image
// double r = 0.7;
// double g = 0.7;
// double b = 0.7;
// double a = 1.0;
// double dim = 0.5; // amount to dim the dark squares by
vtkNew<vtkNamedColors> colors;
// colors->GetColor("LightCoral", r, g, b, a);
vtkNew<vtkLookupTable> lut;
lut->SetNumberOfTableValues(2);
lut->SetTableRange(0, 1);
// lut->SetTableValue(0, r, g, b, a);
// lut->SetTableValue(1, dim * r, dim * g, dim * b, a);
// Or we can have fun ...
lut->SetTableValue(0, colors->GetColor4d("Thistle").GetData());
lut->SetTableValue(1, colors->GetColor4d("DarkSlateBlue").GetData());
vtkNew<vtkImageMapToColors> map;
map->SetLookupTable(lut);
map->SetOutputFormatToRGBA();
map->SetInputData(image0);
map->GetExecutive()->Update();
vtkImageData* image = map->GetOutput();
// Convert the image to a rectilinear grid. Each point in the image
// becomes a cubic cell in the grid.
vtkNew<vtkRectilinearGrid> rectgrid;
int extent[6];
image->GetExtent(extent);
extent[1] += 1;
extent[3] += 1;
extent[5] += 1;
rectgrid->SetExtent(extent);
vtkNew<vtkDoubleArray> xcoords;
vtkNew<vtkDoubleArray> ycoords;
vtkNew<vtkDoubleArray> zcoords;
xcoords->SetNumberOfValues(n + 1);
ycoords->SetNumberOfValues(n + 1);
zcoords->SetNumberOfValues(n + 1);
double spacing[3];
image->GetSpacing(spacing);
for (vtkIdType i = 0; i <= n; i++)
{
xcoords->InsertValue(i, i * spacing[0]);
ycoords->InsertValue(i, i * spacing[1]);
zcoords->InsertValue(i, i * spacing[2]);
}
rectgrid->SetXCoordinates(xcoords);
rectgrid->SetYCoordinates(ycoords);
rectgrid->SetZCoordinates(zcoords);
vtkPointData* pointData = image->GetPointData();
vtkCellData* cellData = rectgrid->GetCellData();
cellData->ShallowCopy(pointData);
return rectgrid;
}
} // namespace
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(TableBasedClipDataSetWithPolyData2)
find_package(VTK COMPONENTS
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "TableBasedClipDataSetWithPolyData2: Unable to find the VTK build folder.")
endif()
# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(TableBasedClipDataSetWithPolyData2 MACOSX_BUNDLE TableBasedClipDataSetWithPolyData2.cxx )
target_link_libraries(TableBasedClipDataSetWithPolyData2 PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS TableBasedClipDataSetWithPolyData2
MODULES ${VTK_LIBRARIES}
)
Download and Build TableBasedClipDataSetWithPolyData2¶
Click here to download TableBasedClipDataSetWithPolyData2 and its CMakeLists.txt file. Once the tarball TableBasedClipDataSetWithPolyData2.tar has been downloaded and extracted,
cd TableBasedClipDataSetWithPolyData2/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:
./TableBasedClipDataSetWithPolyData2
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.