Added geometry plotting detail to users guide

docs/source/usersguide/processing.rst

@@ -0,0 +1,98 @@
+.. _usersguide_processing:
+
+=================================
+Data Processing and Visualization
+=================================
+
+This section is intended to explain in detail the recommended procedures for
+carrying out common tasks with OpenMC. While several utilities of varying
+complexity are provided to help automate the process, in many cases it will be
+extremely beneficial to do some coding in Python to quickly obtain results.  In
+these cases, and for many of the provided utilities, it is necessary for your
+Python installation to contain:
+
+* `Numpy <http://www.numpy.org/>`_
+* `Scipy <http://www.scipy.org/>`_
+* `Matplotlib <http://matplotlib.org/>`_ (optional for plotting utilities)
+* `Silomesh <https://github.com/nhorelik/silomesh>`_ (optional for plotting
+  utilities)
+* `VTK <http://www.vtk.org/>`_ (optional for plotting utilities)
+
+----------------------
+Geometry Visualization
+----------------------
+
+Geometry plotting is carried out by creating a plots.xml, specifying plots, and
+running OpenMC with the -plot or -p command-line option (See
+:ref:`usersguide_plotting`).
+
+Plotting in 2D
+--------------
+
+.. image:: ../../img/atr.jpg
+   :height: 200px
+
+After running OpenMC to obtain PPM files, images should be saved to another
+format before using them elsewhere. This cuts down the size of the file by
+orders of magnitude.  Most image viewers and editors that can view PPM images
+can also save to other formats (e.g. `Gimp <http://www.gimp.org/>`_, `IrfanView
+<http://www.irfanview.com/>`_, etc.).  However, more likey the user will want to
+convert to another format on the command line.  This is easily accomplished with
+the ``convert`` command available on most linux distributions as part of the
+`ImageMagick <http://www.imagemagick.org/script/convert.php>`_ package. (On
+Ubuntu: ``sudo apt-get install imagemagick``).  Images are then converted like:
+
+.. code-block:: sh
+
+    convert plot.ppm plot.png
+
+Plotting in 3D
+--------------
+
+.. image:: ../../img/3dgeomplot.png
+   :height: 200px
+
+The binary VOXEL files output by OpenMC can not be viewed directly by any
+existing viewers. In order to view them, they must be converted into a standard
+mesh format that can be viewed in ParaView, Visit, etc. The provided utility
+voxel.py accomplishes this for SILO:
+
+.. code-block:: sh
+
+    <openmc_root>/src/utils/voxel.py myplot.voxel -o output.silo
+
+and VTK:
+
+.. code-block:: sh
+
+    <openmc_root>/src/utils/myplot.voxel --vtk -o output.vti
+
+To use this utility you need either
+
+* `Silomesh <https://github.com/nhorelik/silomesh>`_
+
+or
+
+* `VTK <http://www.vtk.org/>`_ with python bindings - On Ubuntu, these are easily obtained with ``sudo apt-get install python-vtk``
+
+Users can process the binary into any other format if desired by following the
+example of voxel.py.  For the binary file structure, see :ref:`devguide_voxel`.
+
+-------------------
+Tally Visualization
+-------------------
+
+Data Extraction
+---------------
+
+Plotting in 2D
+--------------
+
+Plotting in 3D
+--------------
+
+.. image:: ../../img/3dcore.png
+   :height: 200px
+
+Getting Data into MATLAB
+------------------------