vtk-m/examples/demo/Demo.cxx

//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt for details.
//  This software is distributed WITHOUT ANY WARRANTY; without even
//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
//  PURPOSE.  See the above copyright notice for more information.
//
//  Copyright 2014 Sandia Corporation.
//  Copyright 2014 UT-Battelle, LLC.
//  Copyright 2014 Los Alamos National Security.
//
//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
//  the U.S. Government retains certain rights in this software.
//
//  Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
//  Laboratory (LANL), the U.S. Government retains certain rights in
//  this software.
//============================================================================

#include <vtkm/cont/testing/MakeTestDataSet.h>
#include <vtkm/rendering/Actor.h>
#include <vtkm/rendering/CanvasRayTracer.h>
#include <vtkm/rendering/MapperRayTracer.h>
#include <vtkm/rendering/Scene.h>
#include <vtkm/rendering/View3D.h>
#include <vtkm/cont/DeviceAdapter.h>
#include <vtkm/cont/testing/Testing.h>

#include <vtkm/io/reader/VTKDataSetReader.h>

#include <vtkm/filter/MarchingCubes.h>
#include <vtkm/cont/DataSetFieldAdd.h>

#include <iostream>

void makeScene(const vtkm::cont::DataSet &inputData,
                            const vtkm::rendering::ColorTable &colorTable,
                            const   std::string &fieldName,
                            vtkm::rendering::Scene &scene)
{
    scene.AddActor(vtkm::rendering::Actor(inputData.GetCellSet(),
                                                inputData.GetCoordinateSystem(),
                                                inputData.GetField(fieldName),
                                                colorTable));


}

// This example reads an input vtk file specified on the command-line (or generates a default
// input data set if none is provided), uses VTK-m's rendering engine to render it to an
// output file using OS Mesa, instantiates an isosurface filter using VTK-m's filter
// mechanism, computes an isosurface on the input data set, packages the output of the filter
// in a new data set, and renders this output data set in a separate iamge file, again
// using VTK-m's rendering engine with OS Mesa.

int main(int argc, char* argv[])
{
  // Input variable declarations
  vtkm::cont::DataSet inputData;
  vtkm::Float32 isovalue;
  std::string fieldName;

  // Get input data from specified file, or generate test data set
  if (argc < 3)
  {
    vtkm::cont::testing::MakeTestDataSet maker;
    inputData = maker.Make3DUniformDataSet0();
    isovalue = 100.0f;
    fieldName = "pointvar";
  }
  else
  {
    std::cout << "using: " << argv[1] << " as MarchingCubes input file" << std::endl;
    vtkm::io::reader::VTKDataSetReader reader(argv[1]);
    inputData = reader.ReadDataSet();
    isovalue = atof(argv[2]);
    fieldName = "SCALARS:pointvar";
  }

  typedef vtkm::rendering::MapperRayTracer  Mapper;
  typedef vtkm::rendering::CanvasRayTracer Canvas;

  // Set up a camera for rendering the input data
  const vtkm::cont::CoordinateSystem coords = inputData.GetCoordinateSystem();
  Mapper mapper;
  vtkm::rendering::Camera camera = vtkm::rendering::Camera();

  //Set3DView
  vtkm::Bounds coordsBounds = coords.GetBounds(VTKM_DEFAULT_DEVICE_ADAPTER_TAG());

  camera.ResetToBounds(coordsBounds);

  vtkm::Vec<vtkm::Float32,3> totalExtent;
  totalExtent[0] = vtkm::Float32(coordsBounds.X.Max - coordsBounds.X.Min);
  totalExtent[1] = vtkm::Float32(coordsBounds.Y.Max - coordsBounds.Y.Min);
  totalExtent[2] = vtkm::Float32(coordsBounds.Z.Max - coordsBounds.Z.Min);
  vtkm::Float32 mag = vtkm::Magnitude(totalExtent);
  vtkm::Normalize(totalExtent);
  camera.SetLookAt(totalExtent * (mag * .5f));
  camera.SetViewUp(vtkm::make_Vec(0.f, 1.f, 0.f));
  camera.SetClippingRange(1.f, 100.f);
  camera.SetFieldOfView(60.f);
  camera.SetPosition(totalExtent * (mag * 2.f));
  vtkm::rendering::ColorTable colorTable("thermal");

  // Create a scene for rendering the input data
  vtkm::rendering::Scene scene;
  vtkm::rendering::Color bg(0.2f, 0.2f, 0.2f, 1.0f);
  Canvas canvas(512,512);

  makeScene(inputData, colorTable, fieldName, scene);
  // Create a view and use it to render the input data using OS Mesa
  vtkm::rendering::View3D view(scene,
                                                mapper,
                                                canvas,
                                                camera,
                                                bg);
  view.Initialize();
  view.Paint();
  view.SaveAs("demo_input.pnm");

  // Create an isosurface filter
  vtkm::filter::MarchingCubes filter;
  filter.SetGenerateNormals(false);
  filter.SetMergeDuplicatePoints(false);
  filter.SetIsoValue(isovalue);
  vtkm::filter::ResultDataSet result = filter.Execute( inputData,
                                                       inputData.GetField(fieldName) );
  filter.MapFieldOntoOutput(result, inputData.GetField(fieldName));
  vtkm::cont::DataSet& outputData = result.GetDataSet();
  // Render a separate image with the output isosurface
  std::cout << "about to render the results of the MarchingCubes filter" << std::endl;
  vtkm::rendering::Scene scene2;
  makeScene(outputData, colorTable, fieldName, scene2);


  vtkm::rendering::View3D view2(scene2,
                                                 mapper,
                                                 canvas,
                                                 camera,
                                                 bg);
  view2.Initialize();
  view2.Paint();
  view2.SaveAs("demo_output.pnm");

  return 0;
}