VTK-m

VTK-m is a toolkit of scientific visualization algorithms for emerging processor architectures. VTK-msupports the fine-grained concurrency for data analysis and visualization algorithms required to drive extreme scale computing by providing abstract models for data and execution that can be applied to a variety of algorithms across many different processor architectures.

You can find out more about the design of VTK-m on our wiki

Dependencies

VTK-m Requires:

• C++11 Compiler. VTK-m has been confirmed to work with the following
• GCC 4.8+
• Clang 3.3+
• XCode 5.0+
• MSVC 2013+
• CMake 3.3

Optional dependencies are:

• CUDA Device Adapter
  • Cuda Toolkit 7+
• TBB Device Adapter
  • TBB
• Rendering Module
  • The rendering module requires that you have a extension binding library and one rendering library. A windowing library is not needed expect for some optional tests.
  • Extension Binding
    • GLEW
  • Rendering Canvas
    • OpenGL Driver (See your GPU/iGPU vendor)
    • EGL (See your GPU/iGPU vendor)
    • OSMesa
  • Windowing/Contexts
    • EGL (See your GPU/iGPU vendor)
    • GLFW
    • GLUT

Building

VTK-m supports all majors platforms ( Windows, Linux, OSX ), and uses CMake to generate all the build rules for the project.

$ git clone https://gitlab.kitware.com/vtk/vtk-m.git
$ mkdir vtkm-build
$ cd vtkm-build
$ cmake-gui ../vtk-m
$ make -j<N>
$ make test

The VTK-m CMake configuration supports several options, including what specific device adapters ( e.g. CUDA, TBB ) that you wish to enable. Here are some relevant options

Variable	Description
BUILD_SHARED_LIBS	Enabled by default. Build all VTK-m libraries as shared libraries.
CMAKE_BUILD_TYPE	This statically specifies what build type (configuration) will be built in this build tree. Possible values are empty, Debug, Release, RelWithDebInfo and MinSizeRel. This variable is only meaningful to single-configuration generators (such as make and Ninja).
CMAKE_INSTALL_PREFIX	Directory to install VTK-m into.
VTKm_ENABLE_EXAMPLES	Disabled by default. Turn on building of simple examples of using VTK-m.
VTKm_ENABLE_BENCHMARKS	Disabled by default. Turn on additional timing tests.
VTKm_ENABLE_CUDA	Disabled by default. Enable CUDA backend.
VTKm_CUDA_Architecture	Defaults to native. Specify what GPU architecture(s) to build CUDA code for, options include native, fermi, kepler, maxwell, and pascal.
VTKm_ENABLE_TBB	Disabled by default. Enable Intel Threading Building Blocks backend.
VTKm_ENABLE_TESTING	Enabled by default. Turn on header, unit, worklet, and filter tests.
VTKm_ENABLE_RENDERING	Enabled by default. Turn on the rendering module.
VTKm_USE_64BIT_IDS	Enabled by default. This is the size of integers used to index arrays, points, cells, etc. Use 64 bit precision when on, 32 bit precision when off.
VTKm_USE_DOUBLE_PRECISION	Disabled by default. Precision to use in floating point numbers when no other precision can be inferred. Use 64 bit precision when on, 32 bit precision when off.

Learning

VTK-m offers numerous different ways to learn how to use the provided components. If you are interested in a high level overview of VTK-m a good place to start is with the IEEE Vis talk "VTK-m: Accelerating the Visualization Toolkit for Massively Threaded Architectures" or the older and more technical presentation "VTK-m Overview for Intel Design Review".

If you are interested in learning how to use the existing VTK-m codebase, or how to integrate into your own project, we recommend reading "Part 1: Getting Started" and "Part 2: Using VTK-m" of the VTK-m Users Guide.

If you want to contribute to VTK-m we recommend reading the following sections of the VTK-m Users Guide.

• "Part 2: Using VTK-m"
  • Covers the core fundamental components of VTK-m including data model, worklets, and filters.

• "Part 3: Developing with VTK-m"
  • Covers how to develop new worklets and filters.
• "Part 4: Advanced Development"
  • Covers topics such as new worklet tags, opengl interop and custom device adapters .

Example

The VTK-m source distribution includes a number of examples. The goal of the VTK-m examples is to illustrate specific VTK-m concepts in a consistent and simple format. However, these examples only cover a small part of the capabilities of VTK-m.

Below is a simple example of using VTK-m to load a VTK image file, run the Marching Cubes algorithm on it, and render the results to an image:

vtkm::io::reader::VTKDataSetReader reader("path/to/vtk_image_file");
inputData = reader.ReadDataSet();

vtkm::Float64 isovalue = 100.0f;
std::string fieldName = "pointvar";

// Create an isosurface filter
vtkm::filter::MarchingCubes filter;
filter.SetIsoValue(0, isovalue);
vtkm::filter::ResultDataSet result = filter.Execute( inputData,
                                                     inputData.GetField(fieldName) );
filter.MapFieldOntoOutput(result, inputData.GetField(fieldName));

// compute the bounds and extends of the input data
vtkm::Bounds coordsBounds = inputData.GetCoordinateSystem().GetBounds();
vtkm::Vec<vtkm::Float64,3> totalExtent( coordsBounds.X.Length(),
                                        coordsBounds.Y.Length(),
                                        coordsBounds.Z.Length() );
vtkm::Float64 mag = vtkm::Magnitude(totalExtent);
vtkm::Normalize(totalExtent);

// setup a camera and point it to towards the center of the input data
vtkm::rendering::Camera camera;
camera.ResetToBounds(coordsBounds);

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 mapper, canvas and view that will be used to render the scene
vtkm::rendering::Scene scene;
vtkm::rendering::MapperRayTracer mapper;
vtkm::rendering::CanvasRayTracer canvas(512, 512);
vtkm::rendering::Color bg(0.2f, 0.2f, 0.2f, 1.0f);

// Render an image of the output isosurface
vtkm::cont::DataSet& outputData = result.GetDataSet();
scene.AddActor(vtkm::rendering::Actor(outputData.GetCellSet(),
                                      outputData.GetCoordinateSystem(),
                                      outputData.GetField(fieldName),
                                      colorTable));
vtkm::rendering::View3D view(scene, mapper, canvas, camera, bg);
view.Initialize();
view.Paint();
view.SaveAs("demo_output.pnm");

Contributing

There are many ways to contribute to VTK-m, with varying levels of effort.

• Ask a question on the VTK-m users email list
• Submit a feature request or bug, or add to an existing discussion on the VTK-m Issue Tracker
• Submit a Pull Request to improve VTK-m ++ See CONTRIBUTING.md for detailed instructions on how to create a Pull Request. ++ Submit an Issue or Pull Request for the VTK-m User's Guide

License

VTK-m is distributed under the OSI-approved BSD 3-clause License. See LICENSE.txt for details.