[Archive] More about group management

Message by Mike:

Hi folks,
I tried (and succeeded apart from 3D vis., probably a pth problem) the demo_5 file and the procedure you outlined. Very nice , but now I have two questions:

  1. When is the group editor expected to be ready to process arbitrary geometries and models?
  2. What would be the smartest way to simulate other spacecraft models with SPIS? I have seen the ahrdcoded .py scripts for demo_5, can I take them as a blue print to hard code my own models? What do I have to take care about?

Thanks for answering!

Message by julien:

You can model and attribute groups to all types of geometry. But in this cas don t used “Init default Groups” that have been implemented for Demo_5 only but the groups Editor.
Please follow the following rules:

  1. “Load” a CAD file into the framework

  2. Init the default properties, with button “Prop”. This will load the minimum set of properties needed by the solver to run properly.
    You have three types of properties:

    • a) Material, that defines the propoerties of the surface, typicaly the
      spacecraft. This may include real data related to specific material such as
      Kapton, for example, but also general “data”, like as sun exposition.
    • b) Electrical, that defines macro groups of electric electrodes for the inner
      electric balance. This for the spacecraft.
    • c) “Plasma”, that defines the numerical and physical properties of the
      plasma model. This propertie is abolutly needed by the solver to lanch the
      simulation properly. More especially, this “plasma” will define the
      boundary conditions needed by the plasma solver.
      PlasmaSC corresponds to the spacecraft and should applied on it. It is a
      set of groups of surfaces in the currents models.
      PlasmaBD corresponds to the external boundary of the simulation box. It
      is a set of groups of surfaces in the currents models.
      PlasmaSN corresponds to the computionnal domain. It a set of groups of
      On this basic set, you may add “data” in each “Properties” and extends them.
  3. Edite the groups and attribute properties group by groups.
    The spacecraft surface should have at least:

    • A material
    • An electrical group
    • tagged with PlasmaSC on all of its surfaces

    The external boundary should be tagged with PlasmaBD.
    The computationnal volum should be tagged with PlasmaSN.

At this level, groups are logically defined. They may be deployed or “mapped” using the “Fields” button.
After mapping, values coming from the properties are applied on the mesh and corresponding “DataFields” and “MeshFields” are built. They mayby edited using the “DataField Chooser” and displayed into a 3D view as all DataFields.
It is also possible to visualise groups, by the menu “Groups -> Show groups”. This will build a set of VTK actors that maybe loaded and displayed into the 3D viewer.

Message by Mike:

well, that works with a custom built model (a simple test one similar to demo_5), but the “init solver” task crashes with an error: Key error: surfFlagBd
This is obviously happening right at the start of the spisnum interfaceing, since no other messages appear.
I checked the geometry, but the right surface group is assigned the plasma property PlasmaBD, everthing appears to be correct in the .geo file and the other properties.
Any hints where the problem is ?

Message by Mike:

well I tried this, seems to work. Anyway, I still have troubles of running VTK, it gives strange errors when trying to visualize anything. I will investigate further, but probably ask back.
Thanks for the help!