[MStn CE U13] ItemTypes in ParametricCell definition?

Hi,

I tried to use ItemTypes in Parametric cell, but it seems it does not work in all scenarios.

I'd like to know whether it's bug or it's "by design behavior".

What I tried (I used Strairs cell from MetroStation example):

  • I attached ItemTypes to an element, that was consequently used in Parametric cell definition.
  • I attached another ItemTypes to the model, that contains Parametric cell definition.

[Edited paragraph] When I placed the cell to a model, I see:

  • ItemTypes attached to elements (the cell content) are lost.  It seems the cell is a kind of "black box", so everything inside (elements, constraints, variable etc.) are hidden and only variants and variables are exposed.
  • I was surprised a bit that also ItemTypes attached to the model were lost too.
  • ItemTypes attached to model (parametric cell) are inserted correctly to target model (I probably did something wrong when I wrote the post).

With regards,

  Jan

  • I attached ItemTypes to an element, that was consequently used in Parametric cell definition.

    Did you attempt to attach the item type to the physical element, or through the variables menu?

    ItemTypes attached to elements (the cell content) are lost.  It seems the cell is a kind of "black box", so everything inside (elements, constraints, variable etc.) are hidden and only variants and variables are exposed.

    This is an accurate way of describing the usage of parametric cells, the variables and item types attached to the variables should all be visible within the properties menu. The user can pull reports on them and use the variable driven item types as if they are local variables to the parametric cell.  My understanding as to why this happens is because the parametric cell is considered a shared cell.  As a result you cannot change most attributes of any 3D parametric cell like color or level.  Oddly you can change the attributes of 2D parametric cells, but you still cannot see any information about how it was built or constraints.  2D parametric cells can be extruded and turned into solid geometry tho and retain the parametric variables used to create it for on the fly changes.

    ItemTypes attached to model (parametric cell) are inserted correctly to target model (I probably did something wrong when I wrote the post).

    I haven't done this yet because i only need one item type attached to my parametric cells thus far but i look forward to seeing how it works.

    If you drop status on a parametric cell the underlying constants and construction elements do become exposed, but any variables and variations get lost.

    So far beyond 1 or 2 simple if/then statements and minimal solids constrained to each-other the cells seem to become un-usable very quickly.  I'm still working on trying to learn how to best use them but for the most part i cannot do nearly the same level of parametric modeling that was possible in v8i.  The biggest issue seems to be when the software thinks it's over constrained or cannot resolve an issue it just starts dropping constraints at random resulting in geometry doing un-predictable things.  Beyond that when trying to manipulate a complex parametric cell with more then one 3D component in a model "rotating" the cell or trying to manipulate it can cause the cell to explode trying to keep it's constraints in order.  One would think based on the black box nature of the cell this would be easy it's just geometry being moved, but that is now how it works in practice.  Lastly do not mirror or mirror copy, copy then mirror or mirror then copy a parametric cell mirroring a parametric cell at some point will cause the parametric definition to become lost.  It's a known issue and Bentley will fix it ... one day... I hope.

  • Hi Grant,

    Did you attempt to attach the item type to the physical element, or through the variables menu?

    because I did not explicitly mentioned variables, I do not use ItemTypes to define variables, but to add a custom data to particular element inside parametric cell.

    My question is not about how to define and manage parametric cell(s), but whether it's expected by design or by implementation to maintain custom data (not necessarily ItemTypes, but XAttributes or general EC data) inside parametric cell when it's placed to a model.

    Regards,

      Jan

  • I haven't had a cause for static item type data in a parametric cell but i did a test quick test cell and can confirm your findings.  Item types attached directly to parametric elements are hidden and not exposed in any way.

    Edit: out of curiosity i tried to add a link to one of the elements and this also did not pass through the cell.

  • Item types attached directly to parametric elements are hidden and not exposed in any way.

    That's exactly what I am asking about ;-)

    I hope somebody from Bentley will confirm whether it's by design (parametric cell is generated as geometry only) or it has not been implemented yet.

    Regards,

      Jan

  • Hi Jan,

    Although I cannot say this issue and the issue lined immediately below are 100% related (e.g. underlying issue with MDL API vs. VBA layer only) I thought it may be worth mentioning/referencing:

    [VBA CE U13] Place cell with Item Type does not attach the Item Type (Defect 893174)

    HTH,
    Bob