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Ability to Modify a part from its derived representation.

WiBrWiBr Member Posts: 27 PRO
Imagine a situation where you have two sub-assemblies built in two part studios.  These two subs must interface to one another.  So to design the interface on part studio B, I start be bringing a derived part from part studio A into B.  While designing the interface in B, I decide I want to modify the part from studio A based on the geometry from studio B.  I want the ability to modify a part by modifying it's derived representation. 

On a part studio Im working on, I started with a derived part.  When working in the part studio there was a feature that I wanted to add to the derived part.  Happily it seems that OnShape does let me add features to a derived part and merge them correctly to the derived part. The new features merged correctly, there weren't new parts floating in space or anything. However, when I went back to the derived part's originating part studio, the features didn't transfer back to the root part studio.  This would be extremely useful! 

 I think at the moment the only way then is to derive parts in both directions, derive A to B and also derive B to A, but then I would be constantly going back and forth between part studios.  As I said, it seems that OnShape, intentionally or not, already allows a derived part to be modified.  This improvement would give the designer the option to have these changes propagate back to the originating part in its home part studio.

Thanks for looking at this!



  • Cris_BowersCris_Bowers Member Posts: 281 PRO
    It sounds like what you are actually wanting is "Edit in context" which already exists. Is there a reason that doesn't work for what you are describing?
  • WiBrWiBr Member Posts: 27 PRO
    @Cris_Bowers Thanks for your feedback. It is, but my understanding is that this is only available at the assembly level. But that is a good way to put it, I'd like to have edit-in-context available at the part studio level as well.  In this case, I haven't gotten to putting the assembly together yet. But like I said, it seems that OnShape already allows you to modify the derived model, it doesn't make sense to allow this to be done if it isn't also an option to have it propagate back to the actual model, or at least make that an option. 
  • Cris_BowersCris_Bowers Member Posts: 281 PRO
    Here is a good webinar discussing the workflows and when to use them, I think it explains better than I can. https://www.onshape.com/videos/in-context-vs-derived (jump to 26:39 for In-Context and 52:38 for Derived)
  • owen_sparksowen_sparks Member, Developers Posts: 2,660 PRO
    I might be missing the point, if so excuse me. Yes, Edit in Context is the way to go here if they're existing parts. (If they're new parts then could they both be designed in the same partstudio?) 

    The alarm bells started ringing on Line 1 of your post.  "I'm making an assembly in a partstudio..." 
    Cheers, Owen S.

    Business Systems and Configuration Controller
    HWM-Water Ltd
  • WiBrWiBr Member Posts: 27 PRO

    So the first part of this problem is a problem that exists in OS already.  I was actually just reading another thread you posted in about being able to bring multiple imports into the same part studio.  Both parts are imports from SW.  So Im stuck with them being in seperate part studios.  Edit-in-context would work, yep, but I hadn't built an assembly yet.  I used derived from part A to make a change to part B. Then, as an experiment, I decided to try editing the derived part.  To my delight, I was and am able to modify the derived part.  Why not just let me make those changes stick to the original part?  Why does OS care if I want to edit in a part studio or an assembly?  Apparently, it's possible in both cases, just in the derived, the changes are blocked from going back to its original tab for some reason.  Why let me modify the derived at all if I can't make the changes stick. 

    what are your thoughts on this?  

    Thanks for your thoughts all.
  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 1,451 PRO
    I use 2 tabs for this operation. Possibly using too much real estate.

  • Cris_BowersCris_Bowers Member Posts: 281 PRO
    From the Derived Part help file:
    • Derived features have a one-way correspondence: from the parent Part Studio to the target Part Studio. When you change the feature in the parent Part Studio, the change is reflected in the target Part Studio, but not vice versa.
    • This feature does not accept circular references. For example, when inserting a feature from Part Studio A to Part Studio B, you cannot insert any feature from Part Studio B to Part Studio A. The operation will fail due to the circular reference attempted from Part Studio A to B to A again.

      example of the Derived feature not accepting circular references

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