# WarpCombustor

vtk-examples/Cxx/VisualizationAlgorithms/WarpCombustor

### Description¶

This example demonstrates how to extract "computational planes" from a structured dataset. Structured data has a natural, logical coordinate system based on i-j-k indices. Specifying imin,imax, jmin,jmax, kmin,kmax pairs can indicate a point, line, plane, or volume of data.

In this example, we extract three planes and warp them using scalar values in the direction of the local normal at each point. This gives a sort of "velocity profile" that indicates the nature of the flow.

Other languages

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### Code¶

WarpCombustor.cxx

#include <vtkActor.h>
#include <vtkAppendPolyData.h>
#include <vtkCamera.h>
#include <vtkMultiBlockDataSet.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkPolyDataNormals.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkStructuredGrid.h>
#include <vtkStructuredGridGeometryFilter.h>
#include <vtkStructuredGridOutlineFilter.h>
#include <vtkWarpScalar.h>

// This example demonstrates how to extract "computational planes" from a
// structured dataset. Structured data has a natural, logical coordinate
// system based on i-j-k indices. Specifying imin,imax, jmin,jmax, kmin,kmax
// pairs can indicate a point, line, plane, or volume of data.
//
// In this example, we extract three planes and warp them using scalar values
// in the direction of the local normal at each point. This gives a sort of
// "velocity profile" that indicates the nature of the flow.

int main(int argc, char* argv[])
{
if (argc < 3)
{
std::cout << "Usage: " << argv[0] << " combxyz.bin combq.bin" << std::endl;
return EXIT_FAILURE;
}
// Here we read data from a annular combustor. A combustor burns fuel and air
// in a gas turbine (e.g., a jet engine) and the hot gas eventually makes its
// way to the turbine section.
//
pl3d->SetXYZFileName(argv[1]);
pl3d->SetQFileName(argv[2]);
pl3d->SetScalarFunctionNumber(100);
pl3d->SetVectorFunctionNumber(202);
pl3d->Update();

vtkStructuredGrid* pl3dOutput =
dynamic_cast<vtkStructuredGrid*>(pl3d->GetOutput()->GetBlock(0));

// Planes are specified using a imin,imax, jmin,jmax, kmin,kmax coordinate
// specification. Min and max i,j,k values are clamped to 0 and maximum value.
//
vtkNew<vtkStructuredGridGeometryFilter> plane;
plane->SetInputData(pl3dOutput);
plane->SetExtent(10, 10, 1, 100, 1, 100);

vtkNew<vtkStructuredGridGeometryFilter> plane2;
plane2->SetInputData(pl3dOutput);
plane2->SetExtent(30, 30, 1, 100, 1, 100);
vtkNew<vtkStructuredGridGeometryFilter> plane3;
plane3->SetInputData(pl3dOutput);
plane3->SetExtent(45, 45, 1, 100, 1, 100);

// We use an append filter because that way we can do the warping, etc. just
// using a single pipeline and actor.
//
vtkNew<vtkAppendPolyData> appendF;

vtkNew<vtkWarpScalar> warp;
warp->SetInputConnection(appendF->GetOutputPort());
warp->UseNormalOn();
warp->SetNormal(1.0, 0.0, 0.0);
warp->SetScaleFactor(2.5);

vtkNew<vtkPolyDataNormals> normals;
normals->SetInputConnection(warp->GetOutputPort());
normals->SetFeatureAngle(60);

vtkNew<vtkPolyDataMapper> planeMapper;
planeMapper->SetInputConnection(normals->GetOutputPort());
planeMapper->SetScalarRange(pl3dOutput->GetScalarRange());

vtkNew<vtkActor> planeActor;
planeActor->SetMapper(planeMapper);

// The outline provides context for the data and the planes.
vtkNew<vtkStructuredGridOutlineFilter> outline;
outline->SetInputData(pl3dOutput);

vtkNew<vtkPolyDataMapper> outlineMapper;
outlineMapper->SetInputConnection(outline->GetOutputPort());

vtkNew<vtkNamedColors> colors;

vtkNew<vtkActor> outlineActor;
outlineActor->SetMapper(outlineMapper);
outlineActor->GetProperty()->SetColor(colors->GetColor3d("Black").GetData());

// Create the usual graphics stuff/
//
vtkNew<vtkRenderer> ren1;
vtkNew<vtkRenderWindow> renWin;

vtkNew<vtkRenderWindowInteractor> iren;
iren->SetRenderWindow(renWin);

ren1->SetBackground(colors->GetColor3d("Silver").GetData());

renWin->SetSize(640, 480);
renWin->SetWindowName("WarpCombustor");

// Create an initial view.
ren1->GetActiveCamera()->SetClippingRange(3.95297, 50);
ren1->GetActiveCamera()->SetFocalPoint(8.88908, 0.595038, 29.3342);
ren1->GetActiveCamera()->SetPosition(-12.3332, 31.7479, 41.2387);
ren1->GetActiveCamera()->SetViewUp(0.060772, -0.319905, 0.945498);
iren->Initialize();

// render the image
//
renWin->Render();
iren->Start();
return EXIT_SUCCESS;
}


### CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(WarpCombustor)

find_package(VTK COMPONENTS
CommonColor
CommonCore
CommonDataModel
FiltersCore
FiltersGeneral
FiltersGeometry
IOParallel
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
)

if (NOT VTK_FOUND)
message(FATAL_ERROR "WarpCombustor: 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.")
target_link_libraries(WarpCombustor PRIVATE ${VTK_LIBRARIES} ) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS WarpCombustor MODULES${VTK_LIBRARIES}
)


cd WarpCombustor/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:

./WarpCombustor


WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.