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Full Version: Understanding why certain STEP files contain object groupings ?

From: svenster
2 Feb   [#1]
Hi Forum. McMaster-Carr imports of STEP files contain multiple, discrete "objects" that appear in scene browser as groupings. This makes them particularly easy to work with ( e.g. a door hinge with two leafs that can be easily manipulated/integrated to attach to door and frame ). Other STEP files contain only a single "object" although they too should contain such object groupings. How does one in the industry refer to this feature/function and is it purely a product of the provider of STEP file or something else ?

As an example I'm working with gas springs from ACE ( a Stabilus company ) which provides a really good gas spring calculator, but also 3D models of chosen configurations ( https://ace-cad.de/ ). Regardless of options I choose ( e.g. STEP AP 242, "create model structure", etc. ) I'm unable to get these models with object groupings like McMaster-Carr.

Any insights appreciated,

Sven
From: Michael Gibson
2 Feb   [#2] In reply to [#1]
Hi Sven, do you have an example file where it has the groupings like you want? It's hard to guess at what might be going on just from descriptions, I need to be able to examine the files.

But probably those are object name properties.

Also if you have an example of one where they are not getting set please post it here or e-mail that to me at moi@moi3d.com .

- Michael
From: svenster
2 Feb   [#3]
Hi Michael. I've attached both a McMaster-Carr STEP file that imports as a group with discrete objects and an ACE file that imports as a solid that I wish was organized as group. Just to repeat my question, it is up to the provider of such a file how they organize it ? and if providing a group what would they call such a feature ? Does it rely on a certain STEP version ? I'd like to ask ACE about this if it something they just aren't providing, but first would like to understand how it works and what to ask for.

Appreciatively, Sven

Attachments:
1488A13_Surface-Mount Hinge with Holes.STEP
GS_19_150_0_A8_MA8_A8_OA8_4.stp


From: Michael Gibson
2 Feb   [#4] In reply to [#3]
Hi Sven, so just to make sure I understand, the file "1488A13_Surface-Mount Hinge with Holes.STEP" is the one from McMaster-Carr with the structure you like where the hinge is made up of individual separate objects which can be rotated independently?

And the file "GS_19_150_0_A8_MA8_A8_OA8_4.stp" is the one you don't like, because things like washers, nuts and bolts are all combined together instead of being independent pieces?

- Michael
From: svenster
3 Feb   [#5] In reply to [#4]
Yes. Is this just a product of how provider exports or something else ? If contacting provider do I refer to this feature/ability as "object name properties" or something else ? Thank you
From: Michael Gibson
3 Feb   [#6] In reply to [#5]
Hi Sven, sorry that doesn't have to do with name properties after all.

That's not really anything specific to STEP file format versions or export options, it's just differences in how the modeling was done.

In the case you don't like they did booleans to combine pieces that touch together into a larger single object.

The one you do like they left individual parts alone and did not boolean union together parts that touch.


> If contacting provider do I refer to this feature/ability as "object name properties" or something else ?

I guess you'd say something like "Do you have a version where individual parts such as nuts and bolts are separate objects instead of booleaned together?".

But I kind of doubt they would have it, they have gone through some additional modeling effort to produce it this way.

Probably with the goal of eliminating geometry that is not visible because it's contained inside other parts, to attempt to reduce file size perhaps.

- Michael
From: svenster
3 Feb   [#7] In reply to [#6]
thanks for explaining Michael

Sven