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Displays like the CAVE can be formed in various configurations. In ParaView these configurations can be specified using the PVX configuration XML file. 

==Where to specify this?==
* pvx file can be specified as the last command line argument for any of the server processes. 
* Typically the pvx file is specified for all the executables whose environment is being changed using the pvx file. In case of data-server/render-server configuration, if you are setting up the environment for the two processes groups, then the pvx file must be passed as a command line option to both the executables: pvdataserver and pvrenderserver.
* When running in parallel the file is read on all nodes, hence must be present on all nodes.

==Structure==

<!-- <source lang="xml"> -->
<!-- <?xml version="1.0" ?> -->
<!-- <pvx> -->
<!--   <Process Type="server|dataserver|renderserver"> -->
<!--     <\!--  -->
<!--       The only supported Type values are "server", "dataserver" or "renderserver". -->
<!--       This controls which executable this configuration is applicable to. -->
<!--       There can be multiple <Process /> elements in the same pvx file. -->
<!--       ------------------------------------------------------ -->
<!--       |  Executable     | Applicable Process Type          | -->
<!--       |  pvserver       | server, dataserver, renderserver | -->
<!--       |  pvrenderserver | server, renderserver             | -->
<!--       |  pvdataserver   | server, dataserver               | -->
<!--       ------------------------------------------------------ -->
<!--      -\-> -->
<!--     <Machine name="hostname" -->
<!--              Environment="DISPLAY=m1:0" -->
<!--              LowerLeft="-1.0 -1.0 -1.0" -->
<!--              LowerRight="1.0 -1.0 -1.0" -->
<!--              UpperLeft="-1.0  1.0 -1.0"> -->
<!--       <\!-- -->
<!--          There can be multiple <Machine> elements in a <Process> element,  -->
<!--          each one identifying the configuration for a process.  -->
<!--          All attributes are optional. -->
<!--          name="hostname" -->
<!--          Environment: the environment for the process. -->
<!--          LowerLeft|LowerRight|UpperLeft : CAVE configuration parameters applicable -->
<!--                                           for versions 3.8 or latter only. -->
 
<!--        -\-> -->
<!--     </Machine> -->
<!--   </Process> -->
<!-- </pvx> -->
<!-- </source> -->
* Only 2 vectors ([LowerRight - LowerLef] and [UpperLeft - LowerLeft]) are needed, the third vector is computed from these 2.

== Cave Rendering ==
===Instructions===
* Turn on <code>PARAVIEW_USE_MPI</code> and <code>PARAVIEW_USE_ICE_T</code>
* run the servers using the pvx file: <code>mpiexec -np 2 pvserver cave.pvx</code>
* start and connect a client
=== Notes ===
* See below for an example of a cave configuration file
<source lang="xml">
<?xml version="1.0" ?>
<pvx>
 <Process Type="client" />
 <Process Type="server">
  <!-- 2 render windows will be created on the machine Erna: 
       the first rendering has a camera looking forward,
       the second rendering has a camera looking backward -->
  <Machine Name="Erna"
           Environment="DISPLAY=:0"
           <!-- Camera looks forward:
                 dx = 2, dy = 2, dz = -2
                 Z = -2 defines the view angle  -->
           LowerLeft="-1 -1 -2"
           LowerRight="1 -1 -2"
           UpperLeft="-1  1 -2" />
  <Machine Name="Erna"
           Environment="DISPLAY=:0"
           <!-- Camera looks backward:
                 dx = -2, dy = 2, dz = 2
                 Z = 2 defines the distance from the camera to the view plane  -->
           LowerLeft="1 -1 2"
           LowerRight="-1 -1 2"
           UpperLeft="1  1 2" />
  </Process>
</pvx>
</source>
* See vtkCaveRenderManager::ComputeCamera for more information on how the coordinates are used to configure the cameras
* The rendering on the server is full screen by default. If you want the windows to be smaller for debugging, set the environment variable PV_ICET_WINDOW_BORDERS=1 on the client machine.