vtkWrite support for Lagrangian data

Has vtkWrite support been implemented for Lagrangian? If not, could this be implemented ASAP. We have some cases that we want to animate, and using the old approach of writing the Lagrangian data only, then reconstructing, then converting to vtk is very unwieldy. We’d like to write the spray data in vtk format directly from a functionObject, and be able to select which associated spray properties (d, U, nP, etc.) get output.

Karl

@mark : could you please comment more on this ?

assigned to @mark

Hi Karl,

A major rework of the vtk output is planned (can discuss per email) - I'm not certain that a quick fix is immediate doable (or necessarily desirable). The current vtk output is extremely unwieldy in parallel and results in numerous individual files that are not easily processed anyhow. The future changes would include collecting onto the master and writing from there. Although parallel output for clouds is much easier than for the mesh, it is too large of a change so shortly before release.

For the current requirement (lagrangian output with specified fields) it should be possible to manage this with the new ParaView Catalyst interface with clouds. Assuming that you can get the appropriate ParaView version installed on the cluster. Indeed, with this interface it would be possible to generate the animations directly without writing the intermediate files. If this doesn't work, I would put this issue on the top of the list for post-release changes.

Catalyst is a nice option, but I generate the animations with Blender, so I need the raw vtk files output. Would you please push this to the top of the post-release changes?

As a stop-gap (or a solution), you can also just generate VTK files with Catalyst. May be a bit of overkill if you just want vtk files, but would work.

Nonetheless, I would put this on the top for post-release changes. Please don't hesitate to ping me on it, to make sure it doesn't get forgotten.

mentioned in commit ae8eb1f2

mentioned in merge request !206 (merged)

Hi Karl,

I've added a vtkCloud function object (merge request !206 (merged)) for addition into the next release. It should generally also work ok with the develop branch, but will not compile nicely with the current master (too many changes to wordRes and other bits).

As mentioned in the commit, it streams everything in parallel, which allows you to create VTP files during the simulation and without any reconstructPar. It also generated a file-series (*.vtp.series), which many also be helpful for your situation.

@Prashant - I've tagged this for merging into the next release, so if you'd like to add this to your functionality tests. An example is in under lagrangian/coalChemistryFoam/simplifiedSiwek (parallel or serial).

mentioned in commit ea580190

mentioned in commit 454313da

Now also included runTimePostProcessing support for these clouds and vtp files, some can now also generate basic images on the fly.

mentioned in commit 7c6e0087

mentioned in commit a899ecb7

Thanks Mark. I'll have to try this out once we upgrade to the latest release. We are still on v1712.

mentioned in commit 9db5942d

closed

Mark, trying this out now with v1806. The tutorial case for simplifiedSiwek seems to work. There seems to be a small issue though. In my own case, when I have the start-of-injection (SOI) set to some non-zero value, then the times prior to SOI don't create any *.vtp files (because there is no spray present yet). This is not very nice for the post-processing though, as it'd be better to have an empty/dummy file written for each time that spray is not present. Would this be possible? Otherwise, I'll need to introduce logic on my end to add dummy files for spray to match up with the other time-series files (iso-contours of flame surface, film thickness, etc.) for animation in ParaView/blender.

reopened

I agree. I think I would probably categorize this as a bug as well.

closed via commit 64f7cf2f