Hi Michael,

Using step translation from MoI to NX6 again, the way step translation works at the moment between the two programs is great, there is just one small detail that would be good to improve on, if possible.
If it's too much for V2 deadline then for future releases would be fine.

Here's what happens at the moment;

This is just a basic set up of some primitives in MoI, assuming it is an assembly of solid parts.
I've named each part and then saved as .step



In NX6 when we make an assembly file we make a new part file (*.prt) and assemble existing part files within the newly created one, for example, we would make a new part file 'Assembly_test.prt' then assemble the existing 'Cone.prt', 'Cube.prt', 'Cylinder.prt' and 'Sphere.prt' into this file, in that way if we make a change to one of the parts it will automatically update in the 'Assembly_test.prt'.
MoI step translation almost achieves this except it makes the first solid created in MoI, in this case the cylinder, as the default assembly file which all other parts are assembled into, this shows in the assembly tree, the cylinder is missing in the tree because it is the default assembly file 'Assembly_test_stp'.



Can this be tuned up so when we save as step the file name given is the default assembly file and all objects would be under that?

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Hi Danny - as far as I know I'm not doing anything special to set it up like that with the first created object having any special significance...

That may just be some behavior that NX6 decides to do when there is not any hierarchy set up or something.

What happens if you set the object name to have a kind of hierarchy in it like setting each object name like so:

Assembly:Cone
Assembly:Cube
Assembly:Cylinder
Assembly:Sphere

with that Assembly: appended to the front of the object name, does that change the import behavior at all and give you the hierarchy you want when imported into NX6?

- Michael

Hi Michael,

> with that Assembly: appended to the front of the object name,
> does that change the import behavior at all and give you the
> hierarchy you want when imported into NX6?

Same behavior Michael, how does the step format know that the cylinder was created first?

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Hi Danny,

> Same behavior Michael, how does the step format
> know that the cylinder was created first?

Well, there's some kind of list of objects in the format and anytime you have a list of things one of them is at the start of the list and it probably just grabs that one as the "main" one or whatever... I'm just guessing though.


Could you try one more test? What if you add a space after the colon, so put the object names like this when exporting from MoI:

Assembly: Cone
Assembly: Cube
Assembly: Cylinder
Assembly: Sphere


Does that do anything different?

- Michael

Hi Michael,

> Does that do anything different?

The only difference is the name of the part in the tree, NX defines the colon as an underscore, so in the last object naming suggestion there is an added space after the underscore in the name of the objects.



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Hi Danny, I had seen in some STEP format imports into MoI from other programs that the object names are sometimes set to things like "Assembly: Object" , so that's why I was wondering if just having the names set up like that would work.

Apparently there needs to be more stuff set up in order for it to work, but I'm not really sure.

What happens if you import the attached files in (these have just 3 objects in them), do they work better or the same? These are from a couple of different programs. If they work differently then maybe I will be able to see what is different in their structures.

- Michael

Hi Michael,

rhinov4_test.stp, just comes in as one part file with the three parts no assembly tree at all.

viacad_test.stp, behaves as MoI does.

I've attached a STEP file exported from NX6 which behaves as expected, maybe this file will give you a clue.

NX_test.stp result.



NX files the parts accordingly:





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Hi Danny,

> I've attached a STEP file exported from NX6 which
> behaves as expected, maybe this file will give you a clue.

Thanks for the file! Unfortunately it is kind of similar to trying to figure out the bureaucratic tax code...

I think I will have to ask the guy who makes the STEP libraries that I use about it.

I will not be surprised if it is not an easy thing to mess with though.

- Michael

No problem Michael, it was only a, if you can, question anyway.

The workaround would be to make a template file with an unrelated solid in it as the first object, then when imported into NX just delete that solid and everything else will be in the tree.

Thanks for looking into this!

Cheers

hi Dany and Michael, maybe Group can solve this case? have yuo a target finishing group in v2?

Hi Anis, I'm getting close to working on groups.

> maybe Group can solve this case?

Well, groups in Moi would provide a good interface for how to set up the hierarchies.

But having a good interface access point does not automatically make functions appear for file export at the same time.

I'm still not sure to what extent the STEP library that I use is set up to control hierarchies in the generated STEP file. I think it may not currently have a lot in this area yet.

In fact these last tests by Danny seems to indicate that the hope I had for just putting the group information into object names separated by : characters is not going to do anything at all.

- Michael

hi michael, if i remember correctly... i got same result when import step from another cad system to swx. step cant handle hierarcy. you should use iges. Danny, have you try iges or 3dm ?