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RGrid

vtk-examples/Cxx/RectilinearGrid/RGrid


Description

Creating a rectilinear grid dataset. The coordinates along each axis are defined using an instance of vtkDataArray.

Other languages

See (Python)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

RGrid.cxx

// This example shows how to create a rectilinear grid.
//
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkDoubleArray.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRectilinearGrid.h>
#include <vtkRectilinearGridGeometryFilter.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

int main(int, char*[])
{
  int i;
  static double x[47] = {
      -1.22396,  -1.17188,  -1.11979,  -1.06771,  -1.01562,  -0.963542,
      -0.911458, -0.859375, -0.807292, -0.755208, -0.703125, -0.651042,
      -0.598958, -0.546875, -0.494792, -0.442708, -0.390625, -0.338542,
      -0.286458, -0.234375, -0.182292, -0.130209, -0.078125, -0.026042,
      0.0260415, 0.078125,  0.130208,  0.182291,  0.234375,  0.286458,
      0.338542,  0.390625,  0.442708,  0.494792,  0.546875,  0.598958,
      0.651042,  0.703125,  0.755208,  0.807292,  0.859375,  0.911458,
      0.963542,  1.01562,   1.06771,   1.11979,   1.17188};
  static double y[33] = {-1.25,     -1.17188,  -1.09375,  -1.01562,  -0.9375,
                         -0.859375, -0.78125,  -0.703125, -0.625,    -0.546875,
                         -0.46875,  -0.390625, -0.3125,   -0.234375, -0.15625,
                         -0.078125, 0,         0.078125,  0.15625,   0.234375,
                         0.3125,    0.390625,  0.46875,   0.546875,  0.625,
                         0.703125,  0.78125,   0.859375,  0.9375,    1.01562,
                         1.09375,   1.17188,   1.25};
  static double z[44] = {0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.75, 0.8, 0.9,
                         1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.75, 1.8, 1.9,
                         2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.75, 2.8, 2.9,
                         3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.75, 3.8, 3.9};

  // Create a rectilinear grid by defining three arrays specifying the
  // coordinates in the x-y-z directions.
  vtkNew<vtkDoubleArray> xCoords;
  for (i = 0; i < 47; i++)
  {
    xCoords->InsertNextValue(x[i]);
  }
  vtkNew<vtkDoubleArray> yCoords;
  for (i = 0; i < 33; i++)
  {
    yCoords->InsertNextValue(y[i]);
  }
  vtkNew<vtkDoubleArray> zCoords;
  for (i = 0; i < 44; i++)
  {
    zCoords->InsertNextValue(z[i]);
  }
  // The coordinates are assigned to the rectilinear grid. Make sure that
  // the number of values in each of the XCoordinates, YCoordinates,
  // and ZCoordinates is equal to what is defined in SetDimensions().
  //
  vtkNew<vtkRectilinearGrid> rgrid;
  rgrid->SetDimensions(47, 33, 44);
  rgrid->SetXCoordinates(xCoords);
  rgrid->SetYCoordinates(yCoords);
  rgrid->SetZCoordinates(zCoords);

  // Extract a plane from the grid to see what we've got.
  vtkNew<vtkRectilinearGridGeometryFilter> plane;
  plane->SetInputData(rgrid);
  plane->SetExtent(0, 46, 16, 16, 0, 43);

  vtkNew<vtkPolyDataMapper> rgridMapper;
  rgridMapper->SetInputConnection(plane->GetOutputPort());

  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkActor> wireActor;
  wireActor->SetMapper(rgridMapper);
  wireActor->GetProperty()->SetColor(colors->GetColor3d("Banana").GetData());
  wireActor->GetProperty()->EdgeVisibilityOn();

  // Create the usual rendering stuff.
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(renderer);
  renWin->SetWindowName("RGrid");

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

  renderer->AddActor(wireActor);
  renderer->SetBackground(colors->GetColor3d("Beige").GetData());
  renderer->GetActiveCamera()->Elevation(60.0);
  renderer->GetActiveCamera()->Azimuth(30.0);
  renderer->GetActiveCamera()->Zoom(1.0);
  renderer->ResetCamera();

  renWin->SetSize(640, 480);

  // interact with data
  renWin->Render();
  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(RGrid)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersGeometry
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping RGrid: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(RGrid MACOSX_BUNDLE RGrid.cxx )
  target_link_libraries(RGrid PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(RGrid MACOSX_BUNDLE RGrid.cxx )
  target_link_libraries(RGrid PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS RGrid
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build RGrid

Click here to download RGrid and its CMakeLists.txt file. Once the tarball RGrid.tar has been downloaded and extracted,

cd RGrid/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:

./RGrid

WINDOWS USERS

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