[Paraview] Linking Catalyst example samples with Catalyst

[Ben Boeckel]

On Fri, Jun 06, 2014 at 02:18:42 -0700, Praveen Narayanan wrote:
> I am examining the example code for catalyst from Andy Bauer’s git repository  
> (https://github.com/acbauer/CatalystExampleCode).
> 
> I am trying to learn about the catalyst workflow before using it in my own in
> situ examples.

So, first, there is no requirement to use a Catalyst-the-build to use
Catalyst-the-coprocessing-API. Catalyst builds are meant for use where a
smaller ParaView is a better fit (super computing, lower memory
constraints, etc.). The naming is indeed confusing :( .

> python catalyze.py -i Editions/Base -o ../catalyst_src
> 
> fatal: Not a git repository (or any of the parent directories): .git
> 
> Error: Command '['git', 'rev-parse', '--show-toplevel']' returned non-zero exit
> status 128

You can give `-r <dir>` to tell it the top-level of the source tree.
Without it, it will try and find the top-level using git, which won't
work for tarballs. I'll improve the error message.

> 2)  I tried two of the catalyst sources
> 
> a.  Base+python: This builds properly and links with the example code
> (CxxFullExample)
> 
> b.  Base+essentials+extras+python: This also builds and links with the example
> code, but I get the following runtime error:

When do these errors pop up? The Catalyst build trees are slimmed down
ParaView builds and don't have everything under the sun included (e.g.,
animation classes are missing). If you need other classes, another
edition should be made to include the required classes and proxies.

> 3)  The build base+python runs the example code, but does not connect with
> catalyst. Furthermore, upon running make test to test with the sample python
> script in ‘SampleScripts’ (which basically invokes CxxFullExample with the
> python script as an input argument, I get errors stating that it cannot load
> some vtk modules, which upon looking turn out not to be built at all

<snip>

> I would like to know what I am missing in these builds. It appears that some of
> the vtk modules are not being built:
> 
> Error: Could not import vtkCommonComputationalGeometryPython
> 
> Error: Could not import vtkRenderingCorePython
> 
> Error: Cannot import vtkPVServerManagerDefaultPython
> 
> Error: Cannot import vtkPVServerManagerRenderingPython
> 
> Error: Cannot import vtkPVAnimationPython

Catalyst builds do not build all ParaView modules, so some missing is
expected.

> What is the correct way to get a working run for the examples supplied. Also,
> how do we connect to catalyst after this?  My understanding is that we just
> load up paraview (4.1) and then the simulation would connect to catalyst after
> we hit ‘Connect to Catalyst’ and load up the ‘Coprocessing’ plugin. Does
> paraview have to be built from source?

The way I've done it is that the simulation loads up Catalyst (using
the vtkCPProcessor class). ParaView can create Python scripts for use
with vtkCPPythonScriptPipeline, but if there is a way to use
ParaView-the-application with in-situ runs, I don't know it. Andy?

> More specifically, is there a particular download version that might work, and
> what flags do we turn on in CMakeLists.txt? Is there any other set of examples
> (although I think the git examples demonstrate the workflow quite properly)
> that we could use to try catalyst?

>From a full build, PARAVIEW_ENABLE_CATALYST=ON should be all that is
necessary. From a Catalyst build, the same should be sufficient, but for
any VTK or ParaView classes which you require, you will need to create
an edition to bring them in.

--Ben