Added .visit details
@@ -28,13 +28,55 @@ conventions. While this may appear to be inconvenient, it removes the
possibility that VisIt will include a file that is not in the database. It
also frees VisIt from having to know about dozens of ad hoc file naming
conventions. Having a ``.visit`` file also allows VisIt to make certain
-optimizations when generating a visualization. VisIt provides a **File grouping**
-combo box in the **File open** window (see :numref:`Figure %s<file_open_fig>`) to assist in the creation of a
-``.visit`` file for databases that have no ``.visit`` file. Selecting *On* or *Smart*
-will create a .visit file. Selecting *Off* will not group the files.
-
-Flipbook animation
-~~~~~~~~~~~~~~~~~~
+optimizations when generating a visualization.
+
+To create a ``.visit`` file, simply make a new text file that contains the names
+of the files that you want to visualize and save the file with a ``.visit`` extension.
+
+* Visit will take the first entry in the ``.visit`` file and attempt to determine the
+ appropriate plugin to read the file.
+* Not all plugins can be used with ``.visit`` files. In general, **MD** or **MT** formats
+ sometimes do not work.
+
+ * An **MT** file is a file format that provides multiple time steps in a single file. Thus,
+ grouping multiple **MT** files to produce a time series may not be supported.
+ * An **MD** file is one that provides multiple domains in a single file. Thus, grouping
+ multiple **MD** files to produce a view of the whole may not be supported.
+
+Here is an example ``.visit`` file that groups time steps together. These files should contain
+1 time step per file.
+
+.. code-block:: none
+
+ timestep0.silo
+ timestep1.silo
+ timestep2.silo
+ timestep3.silo
+ ...
+
+Here is an example ``.visit`` file that groups various smaller domain files into a whole dataset
+that VisIt can visualize. Note the use of the ``!NBLOCKS`` directive and how it designates the
+number of files in a time step that constitute the whole domain. The ``!NBLOCKS`` directive must
+be on the first line of the file. In this example, we have 2 time steps each composed of 4 domain
+files.
+
+.. code-block:: none
+ :emphasize-lines: 1
+
+ !NBLOCKS 4
+ timestep0_domain0.silo
+ timestep0_domain1.silo
+ timestep0_domain2.silo
+ timestep0_domain3.silo
+ timestep1_domain0.silo
+ timestep1_domain1.silo
+ timestep1_domain2.silo
+ timestep1_domain3.silo
+ ...
+
+VisIt provides a **File grouping** combo box in the **File open** window (see :numref:`Figure %s<file_open_fig>`) to assist in the creation of a ``.visit`` file for databases that
+have no ``.visit`` file. Selecting *On* or *Smart* will create a .visit file. Selecting *Off*
+will not group the files.
.. _file_open_fig:
@@ -42,6 +84,9 @@ Flipbook animation
File open window
+Flipbook animation
+~~~~~~~~~~~~~~~~~~
+
.. _animation_buttons:
.. figure:: images/animationtoolbar.png
