# BlankPoint

vtk-examples/Cxx/StructuredGrid/BlankPoint

Other languages

See (Python), (Java)

Question

### Code¶

BlankPoint.cxx

#include <vtkActor.h>
#include <vtkDataSetMapper.h>
#include <vtkIdList.h>
#include <vtkMath.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkStructuredGrid.h>
#include <vtkStructuredGridGeometryFilter.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkXMLStructuredGridWriter.h>

int main(int, char*[])
{
vtkNew<vtkNamedColors> colors;

// Create a grid
vtkNew<vtkStructuredGrid> structuredGrid;

vtkNew<vtkPoints> points;

unsigned int gridSize = 8;
unsigned int counter = 0;
// Create a 5x5 grid of points
for (unsigned int j = 0; j < gridSize; j++)
{
for (unsigned int i = 0; i < gridSize; i++)
{
if (i == 3 && j == 3) // Make one point higher than the rest
{
points->InsertNextPoint(i, j, 2);
std::cout << "The different point is number " << counter << std::endl;
}
else
{
// Make most of the points the same height
points->InsertNextPoint(i, j, 0);
}
counter++;
}
}

// Specify the dimensions of the grid
structuredGrid->SetDimensions(gridSize, gridSize, 1);

structuredGrid->SetPoints(points);

structuredGrid->BlankPoint(27);
structuredGrid->Modified();

// Check.
auto isVisible = [&structuredGrid](int const& ptNum) {
if (structuredGrid->IsPointVisible(ptNum))
{
std::cout << "Point: " << ptNum << " is visible" << std::endl;
}
else
{
std::cout << "Point: " << ptNum << " is not visible" << std::endl;
}
};

// Should not be visible.
isVisible(27);
// Should be visible.
isVisible(7);

// Create a mapper and actor
vtkNew<vtkDataSetMapper> gridMapper;
gridMapper->SetInputData(structuredGrid);

vtkNew<vtkActor> gridActor;
gridActor->SetMapper(gridMapper);
gridActor->GetProperty()->EdgeVisibilityOn();
gridActor->GetProperty()->SetEdgeColor(colors->GetColor3d("Blue").GetData());

// Create a renderer, render window, and interactor
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->SetWindowName("BlankPoint");

vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
renderWindowInteractor->SetRenderWindow(renderWindow);

// Add the actor to the scene
renderer->SetBackground(colors->GetColor3d("ForestGreen").GetData());

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

renderWindowInteractor->Start();

return EXIT_SUCCESS;
}


### CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(BlankPoint)

find_package(VTK COMPONENTS
CommonColor
CommonCore
CommonDataModel
FiltersGeometry
IOXML
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
)

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


cd BlankPoint/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:

./BlankPoint


WINDOWS USERS

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