I am a beginner and I am trying to visualize a .vtu file (test.vtu) and show the points’ Z direction displacement.
The follwing is my cxx and CMake code:
ReadUnstructuredGrid.cxx:
#include <vtkActor.h>
#include <vtkDataSetMapper.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkXMLUnstructuredGridReader.h>
#include <vtkDataset.h>
#include <vtkCellData.h>
#include <vtkLookupTable.h>
#include <vtkUnstructuredGrid.h>
#include <vtkPointData.h>
#include <vtkDataArray.h>
#include <vtkScalarBarActor.h>
#include <vtkCameraOrientationWidget.h>
int main(int argc, char *argv[])
{
// parse command line arguments
if (argc < 2)
{
std::cerr << "Usage: " << argv[0] << " Filename(.vtu) e.g. tetra.vtu"
<< std::endl;
return EXIT_FAILURE;
}
std::string filename = argv[1];
// read all the data from the file
vtkNew<vtkXMLUnstructuredGridReader> reader;
reader->SetFileName(filename.c_str());
reader->Update();
vtkNew<vtkNamedColors> colors;
vtkSmartPointer<vtkLookupTable> lut = vtkSmartPointer<vtkLookupTable>::New();
lut->SetRange(0.0, 0.03); //the displacement ranges from 0 to 0.03
lut->SetNumberOfColors(256);
lut->Build();
// Create a mapper and actor
vtkNew<vtkDataSetMapper> mapper;
vtkDataSet *dataSet = reader->GetOutputAsDataSet();
dataSet->Print(std::cout);
mapper->SetInputConnection(reader->GetOutputPort());
mapper->ScalarVisibilityOn();
mapper->SetLookupTable(lut);
mapper->SetColorModeToMapScalars();
mapper->SetScalarModeToUsePointFieldData();
mapper->ColorByArrayComponent("Displacement", 2);
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
actor->GetProperty()->SetOpacity(0.5);
actor->GetProperty()->EdgeVisibilityOn();
actor->GetProperty()->SetLineWidth(2.0);
// actor->GetProperty()->SetColor(colors->GetColor3d("MistyRose").GetData());
// vtkNew<vtkProperty> backFace;
// backFace->SetColor(colors->GetColor3d("Tomato").GetData());
// actor->SetBackfaceProperty(backFace);
// add a scalarBar
vtkNew<vtkScalarBarActor> colBar;
colBar->SetMaximumHeightInPixels(500);
colBar->SetLookupTable(lut);
// Create a renderer, render window, and interactor
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->AddRenderer(renderer);
vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
renderWindowInteractor->SetRenderWindow(renderWindow);
// Add the actor to the scene
renderer->AddActor(actor);
renderer->SetBackground(colors->GetColor3d("Wheat").GetData());
renderer->AddActor2D(colBar);
//add a xyz
vtkNew<vtkCameraOrientationWidget> widgetCam;
widgetCam->SetParentRenderer(renderer);
widgetCam->On();
// Render and interact
renderWindow->SetSize(640, 480);
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt:
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(ReadUnstructuredGrid)
find_package(VTK COMPONENTS
CommonColor
CommonCore
IOXML
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
RenderingAnnotation
InteractionWidgets
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "ReadUnstructuredGrid: 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(ReadUnstructuredGrid MACOSX_BUNDLE ReadUnstructuredGrid.cxx )
target_link_libraries(ReadUnstructuredGrid PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS ReadUnstructuredGrid
MODULES ${VTK_LIBRARIES}
)
The test.vtu file has been validated by paraview that its displacement is from 0 to 0.03, thus I set the lookupTable range from 0 to 0.03, However, the colorBar still shows the range from 0 to 1 as the screenshot shows:
I am not sure if my code is correct, I just googled the relative information and followed those examples. So if there’re any mistake in my code, please correct it. Thank you
test.7z (2.7 MB)