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SingleSplat

Repository source: SingleSplat

Description

This example shows a single elliptical splat.

Info

See Figure 9-38a in Chapter 9 The VTK Textbook.

Other languages

See (Python)

Question

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

Code

SingleSplat.cxx

#include <vtkActor.h>
#include <vtkCellArray.h>
#include <vtkConeSource.h>
#include <vtkContourFilter.h>
#include <vtkDoubleArray.h>
#include <vtkGaussianSplatter.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkOutlineFilter.h>
#include <vtkPointData.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

#include <array>

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

  vtkNew<vtkRenderer> aren;
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(aren);
  vtkNew<vtkRenderWindowInteractor> iren;
  iren->SetRenderWindow(renWin);

  // Create single splat point.
  vtkNew<vtkPoints> pts;
  vtkNew<vtkCellArray> verts;
  vtkNew<vtkDoubleArray> norms;
  vtkNew<vtkDoubleArray> scalars;

  std::array<double, 3> x{0.0, 0.0, 0.0};
  pts->InsertNextPoint(x.data());
  norms->SetNumberOfTuples(1);
  norms->SetNumberOfComponents(3);
  std::array<double, 3> n{0.707, 0.707, 0.0};
  norms->InsertTuple(0, n.data());
  scalars->SetNumberOfTuples(1);
  scalars->SetNumberOfComponents(1);
  scalars->InsertTuple1(0, 1.0);

  verts->InsertNextCell(1);
  verts->InsertCellPoint(0);

  vtkNew<vtkPolyData> pData;
  pData->SetPoints(pts);
  pData->SetVerts(verts);
  pData->GetPointData()->SetNormals(norms);
  pData->GetPointData()->SetScalars(scalars);

  // Splat point and generate isosurface.
  vtkNew<vtkGaussianSplatter> splat;
  splat->SetInputData(pData);
  splat->SetModelBounds(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
  splat->SetSampleDimensions(75, 75, 75);
  splat->SetRadius(0.5);
  splat->SetEccentricity(5.0);
  splat->SetExponentFactor(-3.25);
  vtkNew<vtkContourFilter> contour;
  contour->SetInputConnection(splat->GetOutputPort());
  contour->SetValue(0, 0.9);
  vtkNew<vtkPolyDataMapper> splatMapper;
  splatMapper->SetInputConnection(contour->GetOutputPort());
  vtkNew<vtkActor> splatActor;
  splatActor->SetMapper(splatMapper);

  // Create outline.
  vtkNew<vtkOutlineFilter> outline;
  outline->SetInputConnection(splat->GetOutputPort());
  vtkNew<vtkPolyDataMapper> outlineMapper;
  outlineMapper->SetInputConnection(outline->GetOutputPort());
  vtkNew<vtkActor> outlineActor;
  outlineActor->SetMapper(outlineMapper);
  outlineActor->GetProperty()->SetColor(colors->GetColor3d("Brown").GetData());

  // Create cone to indicate direction.
  vtkNew<vtkConeSource> cone;
  cone->SetResolution(24);
  vtkNew<vtkPolyDataMapper> coneMapper;
  coneMapper->SetInputConnection(cone->GetOutputPort());
  vtkNew<vtkActor> coneActor;
  coneActor->SetMapper(coneMapper);
  coneActor->SetScale(0.75, 0.75, 0.75);
  coneActor->RotateZ(45.0);
  coneActor->AddPosition(0.50, 0.50, 0.0);
  coneActor->GetProperty()->SetColor(colors->GetColor3d("DeepPink").GetData());
  //
  // Rendering stuff.
  //
  aren->SetBackground(colors->GetColor3d("Beige").GetData());
  aren->AddActor(splatActor);
  aren->AddActor(outlineActor);
  aren->AddActor(coneActor);

  renWin->SetSize(640, 640);
  renWin->SetWindowName("SingleSplat");
  renWin->Render();

  // interact with data.
  iren->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(SingleSplat)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  FiltersCore
  FiltersModeling
  FiltersSources
  ImagingHybrid
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

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

Download and Build SingleSplat

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

cd SingleSplat/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:

./SingleSplat

WINDOWS USERS

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