vtk-m/tutorial/README.md

VTK-m Tutorial

This page contains materials and instructions for the VTK-m tutorial. Slides are available, and the instructions for getting the example source code exercises are below.

Developers interested in VTK-m should also consult The VTK-m User's Guide, which contains a quick start guide along with detailed documentation of most of VTK-m's features.

Further information is available at https://m.vtk.org.

Downloading VTK-m

The tutorial materials are maintained as part of the VTK-m code repository to help keep the examples up to date. Thus, getting, compiling, and running the tutorial examples is all part of VTK-m itself.

There are two options for getting the VTK-m source code. You could either download a tarball for a release or you can clone the source code directly from the VTK-m git repository.

Downloading a VTK-m Release Tarball

Souce code archives for every VTK-m release are posted on the VTK-m releases page in multiple archive formats. Simply download an archive for the desired version of VTK-m and extract the contents from that archive.

Cloning the VTK-m Git Repository

Developers familiar with git might find it easier to simply clone the VTK-m git repository. The latest VTK-m release is always on the release branch and can be cloned as so.

git clone --branch release https://gitlab.kitware.com/vtk/vtk-m.git

If you are feeling more daring, you can simply clone the main branch with the latest developments.

git clone https://gitlab.kitware.com/vtk/vtk-m.git

Building VTK-m and the Tutorial Examples

To build VTK-m, you will need at a minimum CMake and, of course, a C++ compiler. The VTK-m dependencies list has details on required and optional packages.

When configuring the build with CMake, turn on the VTKm_ENABLE_TUTORIALS option. There are lots of other options available including the ability to compile for many different types of devices. But if this is your first experience with VTK-m, it might be best to start with a simple build.

Here is a list of minimal commands to download and build VTK-m.

git clone --branch release https://gitlab.kitware.com/vtk/vtk-m.git
mkdir vtk-m-build
cd vtk-m-build
cmake ../vtk-m -DVTKm_ENABLE_TUTORIALS=ON
make -j8

The first line above downloads VTK-m using git. You can choose to download a release as described above. Note that if you do so, the source code will be placed in a directory named something like vtk-m-vX.X.X rather than the vtk-m directory you get by default when cloning VTK-m.

Examples

The tutorial contains several examples that can be built and edited. Each example is described in detail in the slides. Here is a brief description of each one, listed from most basic to increasing complexity.

• io.cxx A bare minimum example of loading a DataSet object from a data file and then writing it out again.
• contour.cxx A basic example of running a filter that extracts isosurfaces from a data set.
• contour_two_fields.cxx A simple extension of contour.cxx that selects two of the input fields to be passed to the output.
• two_filters.cxx Further extends the contour.cxx example by running a sequence of 2 filters. The first extracts the isosurfaces and the second clips the surface by a second fields.
• rendering.cxx Demonstrates how to render data in VTK-m.
• error_handling.cxx Demonstrates catching exceptions to react to errors in VTK-m execution.
• logging.cxx Uses VTK-m's logging mechanism to write additional information to the program output.
• mag_grad.cxx The implementation of a simple VTK-m filter which happens to take the magnitude of a vector.
• point_to_cell.cxx A slightly more complicated filter that averages the values of a point field for each cell.
• extract_edges.cxx A fully featured example of a nontrivial filter that extracts topological features from a mesh.