For the visualization of restart and solution files the open source software ParaView by Kitware is used, see https://www.paraview.org. To visualize your data, you, therfore, need to install ParaView. When installing ParaView, make sure to enable MPI-, Python- and QT-support.

Solution files (VTU)

The Finite volume (FV) allows to write solution files in VTU format by defining the property outputFormat = "VTU" in the properties file. VTU is a ParaView native file format, therefore, VTU files can be loaded by any standart ParaView installation. Just click load, select the desired solution file and hit apply.

Restart files (Netcdf)

In m-AIA the restart files and the grid file are written in Netcdf format. To load Netcdf files created with m-AIA, the m-AIA ParaView plugins from the git repository are required. Several custom m-AIA plugins are available. The most important is the m-AIA reader plugin called AIAReaderParrotEmbedded. The reader plugin is an interface between the m-AIA file format and ParaView. It reads the m-AIA file and converts the Cartesian mesh to a vtkunstructuredgrid, which is then passed to ParaView. The other plugins are independet of m-AIA and present custom ParaView filters usefull for flow visualization. A list of the available plugins is given below.

Parallel visualization

The m-AIA reader plugin is fully parallelized. To load data files in parallel, the ParaView Client musst be connected to a ParaView Server. For the parallel visualization the m-AIA reader plugin adds halos cells to the grid for the communication between the grid boundaries. The additional memory required for the halo cells is computed automatically. However, if a large number of processors is used, a manual adjustment of the precalculated memory increase is necessary. Therefore, if your ParaView session crashes, you can try increasing the property

Increase average (cell) memory by: X.X

in the ParaView GUI.

List of available plugins.

Plugin	Type	Description
AIAReaderParrotEmbedded	Reader	The reader plugin is used to load Netcdf files created with
Calc	Filter	Transfers cell data to point data and stores velocity components u, v, w in the vector velocity
$\Delta$-Criterion	Filter	Computes delta criterion $ \Delta = (\frac{1}{3} Q)^3 + (\frac{det \nabla u}{2})^2$, see Q-Criterion for $ Q$
Partition	Filter	Visualizes the grid partitioning for a given number of processes. Can only be used on grid files
Kinematic Vorticity	Filter	Computes the kinematic vorticity
$\lambda_2$-Criterion	Filter	Computes the $\lambda_2$-criterion (Second eigenvalue $ \lambda_2 $ of ( $\Omega^2 + S^2 $), see Q-Criterion for $ \Omega $ and $ S $)
Q-Criterion	Filter	Computes the Q-criterion $ Q = \frac{1}{2} \cdot (\|\|\Omega \|\|_2^2 - \|\|S \|\|_2^2) $ $ \Omega = [\partial u_i / \partial x_j - \partial u_j / \partial x_i] \, , \quad S = [\partial u_i / \partial x_j + \partial u_j / \partial x_i] $
Solution Diff	Filter	Compares to data files
Heat Release	Filter	Deprecated
Surface Error Calculator	Filter	Deprecated
Surface To Grid	Filter	Deprecated
Triangulate Boundary Filter	Filter	Deprecated
WSS	Filter	Deprecated

Building the plugins

TODO: Move to plugin documentation

To build the reader plugin you need a working version of ParaView and the m-AIA source files. The necessary m-AIA io routines required to read and load the m-AIA Netcdf files are then directly compiled into the reader plugin. First, check out the latest plugins from the git repository. To build the plugins use the configure script located in the main directory.

Create directories build and and install
Got to directory build
Update paths in the respective host file in ./aux/hosts/
If you have not yet created a host file, you need add one for your machine and update the aux/gethost script
Run ../configure from build directory
If an error occurs, check the config.log and solve the issue
Run ccmake ../. and update the CMAKE_INSTALL_PREFIX to directory install
Run make install

By running make install builds dynamic libraries .so and stores them in install/lib64/. You can now either load these libraries in ParaView manually or set the $PV_PLUGIN_PATH such that ParaView finds the libraries. Once the libraries are loaded, you can use them in ParaView.