IntermixedUnstructuredGrid
Repository source: IntermixedUnstructuredGrid
Question
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Code¶
IntermixedUnstructuredGrid.cxx
/* converted from:
*
https://github.com/Kitware/VTK/blob/49fbbe479dfdf47c86c02d6cae48c41b9c844b04/Examples/VolumeRendering/Tcl/IntermixedUnstructuredGrid.tcl
*
*/
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkColorTransferFunction.h>
#include <vtkContourFilter.h>
#include <vtkDataSetTriangleFilter.h>
#include <vtkNew.h>
#include <vtkPiecewiseFunction.h>
#include <vtkPolyDataMapper.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSLCReader.h>
#include <vtkStructuredPointsReader.h>
#include <vtkThreshold.h>
#include <vtkUnstructuredGridVolumeRayCastMapper.h>
#include <vtkVolumeProperty.h>
int main(int argc, char* argv[])
{
if (argc < 3)
{
std::cerr << "Usage: " << argv[0]
<< " file.vtk file.slc e.g. ironProt.vtk neghip.slc" << std::endl;
return EXIT_FAILURE;
}
// Create the reader for the data
// This is the data the will be volume rendered
vtkNew<vtkStructuredPointsReader> reader;
reader->SetFileName(argv[1]);
// create a reader for the other data that will
// be contoured and displayed as a polygonal mesh
vtkNew<vtkSLCReader> reader2;
reader2->SetFileName(argv[2]);
// convert from vtkImageData to vtkUnstructuredGrid, remove
// any cells where all values are below 80
vtkNew<vtkThreshold> thresh;
thresh->SetUpperThreshold(80);
thresh->SetThresholdFunction(vtkThreshold::THRESHOLD_UPPER);
// thresh->ThresholdByUpper(80);
thresh->AllScalarsOff();
thresh->SetInputConnection(reader->GetOutputPort());
vtkNew<vtkDataSetTriangleFilter> trifilter;
trifilter->SetInputConnection(thresh->GetOutputPort());
// Create transfer mapping scalar value to opacity
vtkNew<vtkPiecewiseFunction> opacityTransferFunction;
opacityTransferFunction->AddPoint(80, 0.0);
opacityTransferFunction->AddPoint(120, 0.2);
opacityTransferFunction->AddPoint(255, 0.2);
// Create transfer mapping scalar value to color
vtkNew<vtkColorTransferFunction> colorTransferFunction;
colorTransferFunction->AddRGBPoint(80.0, 0.0, 0.0, 0.0);
colorTransferFunction->AddRGBPoint(120.0, 0.0, 0.0, 1.0);
colorTransferFunction->AddRGBPoint(160.0, 1.0, 0.0, 0.0);
colorTransferFunction->AddRGBPoint(200.0, 0.0, 1.0, 0.0);
colorTransferFunction->AddRGBPoint(255.0, 0.0, 1.0, 1.0);
// The property describes how the data will look
vtkNew<vtkVolumeProperty> volumeProperty;
volumeProperty->SetColor(colorTransferFunction);
volumeProperty->SetScalarOpacity(opacityTransferFunction);
volumeProperty->ShadeOff();
volumeProperty->SetInterpolationTypeToLinear();
// The mapper / ray cast function know how to render the data
vtkNew<vtkUnstructuredGridVolumeRayCastMapper> volumeMapper;
volumeMapper->SetInputConnection(trifilter->GetOutputPort());
vtkNew<vtkRenderWindow> renWin;
renWin->SetSize(640, 512);
vtkNew<vtkRenderer> ren1;
// contour the second dataset
vtkNew<vtkContourFilter> contour;
contour->SetValue(0, 80);
contour->SetInputConnection(reader2->GetOutputPort());
// create a mapper for the polygonal data
vtkNew<vtkPolyDataMapper> mapper;
mapper->SetInputConnection(contour->GetOutputPort());
mapper->ScalarVisibilityOff();
// create an actor for the polygonal data
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
ren1->AddViewProp(actor);
ren1->SetBackground(0.1, 0.4, 0.2);
renWin->AddRenderer(ren1);
renWin->SetWindowName("IntermixedUnstructuredGrid");
vtkNew<vtkRenderWindowInteractor> iren;
iren->SetRenderWindow(renWin);
vtkNew<vtkVolume> volume;
volume->SetMapper(volumeMapper);
volume->SetProperty(volumeProperty);
ren1->AddVolume(volume);
ren1->ResetCamera();
ren1->GetActiveCamera()->Zoom(1.5);
// Render composite. In default mode. For coverage.
renWin->Render();
iren->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(IntermixedUnstructuredGrid)
find_package(VTK COMPONENTS
CommonCore
CommonDataModel
FiltersCore
FiltersGeneral
IOImage
IOLegacy
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
RenderingVolume
RenderingVolumeOpenGL2
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "IntermixedUnstructuredGrid: 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(IntermixedUnstructuredGrid MACOSX_BUNDLE IntermixedUnstructuredGrid.cxx )
target_link_libraries(IntermixedUnstructuredGrid PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS IntermixedUnstructuredGrid
MODULES ${VTK_LIBRARIES}
)
Download and Build IntermixedUnstructuredGrid¶
Click here to download IntermixedUnstructuredGrid and its CMakeLists.txt file. Once the tarball IntermixedUnstructuredGrid.tar has been downloaded and extracted,
cd IntermixedUnstructuredGrid/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:
./IntermixedUnstructuredGrid
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.