Hey there :)

we use MoI for the tessellation process and the convert from .STEP files to polygonal meshes.
It's very useful to us because of the n-gon preservation. So, thanks for this great piece of software :)

But one point really makes it unusable for us, with larger assemblies. We seem to loose all hierarchy or grouping information of the parts within the .STEP file? It flattens the content.

Is there any chance to preserve this logical groups during the convert? At least it would be useful to store the original full path as an attribute on the converted objects.
From that we would be able to reconstruct the hierarchy.

So for example keep
/empty/empty_txyz/partname

and don't prune it to just
/partname

From my humble layman's point of view, it shouldn't be that difficult to retain this info? But it would mean a significant improvement in the usability of this tool for us :)
Anyways, thanks for your work!

Best regards,
Joachim

Hi Joachim, inside MoI go to Options > General > "Edit .ini file" button and inside moi.ini in the [NURBS Import] section set:

[NURBS Import]
UseHierarchicalNames=y

That will make object names that have the parent/child information embedded in them, like A: B: C: part_name

The names can get quite large with this but hopefully that will give you the structure information you need.

- Michael

Hi Michael,

Ok, that almost did the trick for us ^^
But lead to a follow up problem/question regarding instance handling.

I'll post it based on the example we've tried in comparison:

Picture01:
Alembic export from Blender STEPper: no ideal tessellation, but instance information is preserved within the object path
This would be the prefered handling and path construction from our point of view.



Picture02:
Alembic Export from MoI with "UseHierarchicalNames=y". Hierarchy is there, but instance information is lost.




Picture03:
From MoI with "UseHierarchicalNames=n". Instance information seems preserved, but as initially questioned, the path/hierarchy is lost.




Would it be possible to combine these information?
This way it would be possible to detect instances further down the road and treat them as such.

Thanks for your effort!
Cheers,
Joachim

Hi Joachim,

re:
> Would it be possible to combine these information?

It could be possible but I need to be able to examine the STEP file and the alembic outputs you show screenshots of there.

Can you please e-mail those to me at moi@moi3d.com ?

Thanks, - Michael

Hi Michael,

That would be great! Of course - I'll send it to you.
Thanks for your effort!

Hey Joachim and Michael

Thanks for working on MoI, great software.

For my company, the usecase is almost the same. All we do is convert .step files to polygon formats with MoI.

We have the same problem with preserving the Hierarchy, so I wanted to ask if there are any plans to implement Hierarchies into MoI?

Did you guys solve this workflow issue?

Thanks

Hi Ludwig,

re:
> We have the same problem with preserving the Hierarchy, so I wanted to ask if there are any plans
> to implement Hierarchies into MoI?

Yes, actually MoI v5 has a form of hierarchy now with groups.

But having a way to represent hierarchy at runtime is just one piece, the other pieces are reworking import and export and trying to map between somewhat different concepts in each file format.

One problem is that most of the polygon formats that MOI exports to do not have hierarchy, just FBX I think.

Also although groups in MoI are hierarchical they don't quite map to an assembly structure in STEP format which kind of needs instancing in addition to hierarchy.


> Did you guys solve this workflow issue?

This previous discussion is from almost a year ago, I don't quite remember the details.

- Michael