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15-Moonstone
August 22, 2023
Solved

STEP AP242 and semantic references

  • August 22, 2023
  • 4 replies
  • 5824 views

Hi, everyone. I thought Creo 9 supported semantic references when exporting to STEP AP242 format, but when trying it myself I couldn't get it to work. When I finally looked at the video in the "What's New" documentation and tried to replicate it, I got it to work, and I suddenly realized that the text was carefully written to only mention "notes" (though the title was "Improved STEP AP242 Support for References Included in Annotations").

 

So just to check that I'm not missing anything, for people who have more insight into this than I have: Creo 9 only supports semantic references in STEP export for note annotations, and not for dimensions, geometrical tolerances, etc.? Really seems strange to me; I would have thought that it would be just as easy to implement this for any kind of annotation, so this omission sounds unnecessary. But then I'm not a programmer.

Best answer by StephenW

This may be your answer from PTC or at least helpful Step Analyzer

https://community.ptc.com/t5/System-Administration/Cannot-open-large-STP-file-Creo-not-responding/m-p/895933/highlight/true#M30020

 

4 replies

13-Aquamarine
August 22, 2023

I have no further insight, but I am curious about how exactly you are verifying the application of semantic references. So you have a model in which annotations such as driving and driven dimensions, notes, GD&T annotations, etc. had been set up with sematic surface references. Then you exported to STEP AP242. What application did you then open the STEP file with to verify?  

15-Moonstone
August 23, 2023

I used Creo 9. I.e. I opened the STEP file in Creo directly after exporting it. I had three different annotations: a (driven) dimension, a geometric tolerance and a (leader) note. When I exported to STEP and imported it back into Creo, the semantic references were there for the note (not just the surface the leader is attached to, but another "extra" surface, too), but they were not preserved for the dimension and the GTOL.

23-Emerald III
August 23, 2023

Re-opening in Creo gives a "hint" at what you are dealing with and is by no means a comprehensive evaluation.

For a specific company, the ideal evaluation is to view the step file as it will be viewed by the intended recipient. If there are multiple recipients with potentially multiple viewers, you should evaluate as many as you can and then offer suggestions to the recipients your "approved" or "preferred" viewers.

The technology is developing and capabillities are expanding, I doubt there is one simple solution.

23-Emerald III
August 23, 2023

Have you looking in the STEP file in a text editor. STEP files are just plain text. Look for the text string that was in your original file and see if that information was written to the STEP file. This should help determine if the issue is on the export or the import side. If you have access to a different CAD system, try the import to that one may also give you some direction.

StephenW23-Emerald IIIAnswer
23-Emerald III
August 24, 2023
15-Moonstone
August 25, 2023

This was a neat little tool; thanks for the tip! I tried it on my model, and sure enough, it seems to me that the note carries the extra geometry, but the other two annotations don't.

 

In the screenshot below, we can see that the note has two planes in the "Associated geometry" column: 2974 and 3432. The flatness and position tolerances both point to the exact same two surfaces in Creo, but only one is listed here (2974). The "linear dimension" is only associated with the edge that it measures, whereas in Creo I added various surfaces as supplemental geometry.

 

Pettersson_0-1692946649561.png

 

My conclusion is that in at least this instance, Creo 9 only supports semantic references for notes and not for other types of annotations. Of course, this was just this model, and it would be nice to actually have a text from PTC saying what is supported, but looking at the "What's new" section in the documentation, seeing how it's carefully worded to avoid mentioning annotations in general (except int he title) and how only a note type annotation is demonstrated in the associated video, it seems reasonable to conclude that this is not implemented.

 

Thanks for your help!

11-Garnet
May 6, 2024

The 1st post points to this one as "Solved."  I disagree.  It even says:

 

"My conclusion is that in at least this instance, Creo 9 only supports semantic references for notes and not for other types of annotations. Of course, this was just this model, and it would be nice to actually have a text from PTC saying what is supported..."

11-Garnet
May 6, 2024

This is a serious issue.  STEP AP242 is designed to include semantic PMI in exchanges.  This holds-back industry progress to move toward more 3D-annotations for use across the entire MBE life cycle (not just design).  We've done similar testing at our site, like the author did, with similar results, and found other issues with Creo's import/export of AP242.  As mentioned in other posts here, more testing is needed to determine where exactly the problems occur.  PTC should be testing this, or clearly publish info on what works or doesn't (or maybe we haven't found the right documentation), in each Creo version.

 

This and similar topics came-up at the last PTC conference in the Data Exchange session, which prompted the restarting of the Technical Committee for Data Exchange https://ptcusergroups.ptcuser.org/organization/tc-data-exchange-archive/dashboard .  I'm going to add this PTC Community thread link to the list of reference info in the TC.