# StructuredGrid

VTKExamples/Cxx/StructuredGrid/StructuredGrid

### Description

This example reads and writes points into a structured grid.

Required version: You must have the CVS HEAD of VTK as of 2/17/10.

### Code

StructuredGrid.cxx

    #include <vtkSmartPointer.h>
    #include <vtkStructuredGrid.h>
    #include <vtkXMLStructuredGridWriter.h>
    #include <vtkDataSetMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>

    int main(int, char *[])
    {
      // Create a grid
      vtkSmartPointer<vtkStructuredGrid> structuredGrid =
        vtkSmartPointer<vtkStructuredGrid>::New();

      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
      double x, y, z;

      x = 0.0;
      y = 0.0;
      z = 0.0;

      for(unsigned int k = 0; k < 2; k++)
      {
        z += 2.0;
        for(unsigned int j = 0; j < 3; j++)
        {
          y += 1.0;
          for(unsigned int i = 0; i < 2; i++)
          {
            x += .5;
            points->InsertNextPoint(x, y, z);
          }
        }
      }

      // Specify the dimensions of the grid
      structuredGrid->SetDimensions(2,3,2);
      structuredGrid->SetPoints(points);

      int* dims = structuredGrid->GetDimensions();

      // Retrieve the entries from the grid and print them to the screen
      unsigned int counter = 0;

      for (int k = 0; k < dims[2]; k++)
      {
        for (int j = 0; j < dims[1]; j++)
        {
          for (int i = 0; i < dims[0]; i++)
          {
            double p[3];
            structuredGrid->GetPoint(counter, p);

            double pNew[3];
            structuredGrid->GetPoint(i, j, k, pNew);

            std::cout << "P   : "
                      << p[0] << " "
                      << p[1] << " "
                      << p[2] << std::endl;
            std::cout << "PNew: "
                      << pNew[0] << " "
                      << pNew[1] << " "
                      << pNew[2] << std::endl;

            counter++;
          }
        }
      }

      // Create a mapper and actor
      vtkSmartPointer<vtkDataSetMapper> mapper =
        vtkSmartPointer<vtkDataSetMapper>::New();
      mapper->SetInputData(structuredGrid);

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      // Create a renderer, render window, and interactor
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      // Add the actor to the scene
      renderer->AddActor(actor);
      renderer->SetBackground(.3, .6, .3); // Background color green

      // Render and interact
      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(StructuredGrid)

    find_package(VTK COMPONENTS
      vtkCommonCore
      vtkCommonDataModel
      vtkIOXML
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping StructuredGrid: ${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(StructuredGrid MACOSX_BUNDLE StructuredGrid.cxx )
      target_link_libraries(StructuredGrid PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(StructuredGrid MACOSX_BUNDLE StructuredGrid.cxx )
      target_link_libraries(StructuredGrid PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS StructuredGrid
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build StructuredGrid

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

    cd StructuredGrid/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:

    ./StructuredGrid

WINDOWS USERS

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