STEP exports from CREO Parametric fail to import in other software products

[LW_10252515]

Hi everyone. 

Not a Creo user myself, but trying to narrow down on a problem with one of our suppliers who use Creo. 

The provide (rather large, hundreds of MB to 1.x GB) complex models to us as STEP files which we fail to import.

We on our end use Autodesk tools (Inventor, Autocad, Navisworks) and another simple Step Viewer (not by Autodesk). That is, the models fail to import on at least two (if not three) different import kernels/backends. 

Of course I'm in contact with Autodesk support but cannot simply give them the models (yet)... IP rights/concerns, you know, lengthy progress to set up NDAs and such.

We did recieve working models form that supplier in the past ("Automotive" AP214 format) which were imported successfully. We then received a more recent model in AP242 format which we were not able to read (importers of all mentioned tools fail after endless hours of "thinking", as if the model causes infinite loops or such).

I've then asked to get a model again in AP214 format, but this does not import now, too.

At the same time we do recieve various step files from small to very large from other source applications / suppliers which we can import perfectly fine. 

Makes me think that either some particular part in that complex assembly is "bad", or ... idk.

So my question is: anyone got any idea on what the cause may be? Any "known problematic" options on the CREO export side settings that one should better leave out? Any hints would welcome, so that I can maybe test this through with the engineers on the supplier's side.

Does Creo Para create some sort of "export log" in which it would give warnings about problematic parts? The imports on my end unfortunately say "nothing" at all, just run, think, eat all available memory... and fail at some point (in touch with Autodesk on that, yes....)

Thanks,

Lars

[MartinHanak]

Hi,

please ask Creo user to export STEP and import it back to Creo. What does happen ?

It would also be good to know which version was used when AP214 STEP files could be imported and which is now in use.

[LW_10252515]

Hi Martin,

source says they always re-import their step exports before passing them on to us. So at their end, out of and then back into Creo, it works.

On our end, software hasn't changed.

Can I tell from the STEP header what version they use? There's the string " 'CREO PARAMETRIC BY PTC INC, 2020053' "

G**gle couldn't match that 2020053  (build number?) to any version list.

Thanks,

Lars

[MartinHanak]

Hi,

the code is written in 1st line of any native Creo file.

Example:

1st line of native Creo part file ... #UGC:2 PART 1937 1460 815 1 1 15 3700 2020342 000002cc \

The code 2020342 belongs to Creo 6.0.5.1.

There is no conversion table ...

[RandyJones]

---

@LW_10252515 wrote:

Can I tell from the STEP header what version they use? There's the string " 'CREO PARAMETRIC BY PTC INC, 2020053' "

G**gle couldn't match that 2020053  (build number?) to any version list.

Thanks,

Lars

---

Build Code 2020053 is the build code for Creo Parametric 7.0.0.0

[TomU]

The Creo build code, which usually matches the xtop.exe file version, does not necessarily correlate with the STEP header.  The header seems to track with the 'gGeometryXX.dll' and 'gTranslatorXX.dll' files instead.

[sacquarone]

Hello @TomU 

Thanks to have pointed that out! I nevertheless confirm in this specific situation that internal datecode 2020053 is the common build code for both xtop.exe and step file generated from Creo Parametric 7.0.0.0.

Hello @LW_10252515 

Just trying to help a bit further from information found in Autodesk Inventor Knowledge Base:

• Ensure that station has enough RAM as per this article here. Note: If the Step file is hundreds of Megas (or even some Giga) large, it's probably expected to fail in the import process attempt on machines with low RAM
• Upgrade to latest version of Inventor. Note: as per this article here, it seems that versions 2015 & 2016 faced some regression (versus 2014) upon import process of large Step files. If we trust this article, version 2017 (and probably above) is supposed to fix this.
• Use Find in Window after import (if the "failure to import" means that import seems successful but nothing is visible on screen after that), as per guidance of article here
• Produce a Shrinkwrap model in Creo Parametric and export Step file from the prt model owning the Shrinkwrap feature, as suggested as workaround for a similar issue discussed in their forum here (mentioned in description, first post) Note: when proceeding in this way, the Step FIle size will be for sure much lower than original Step file generated from Top Assembly in Master Representation. This may therefore help in the retrieval process in Autodesk Inventor of the Step file coming from Shrinkwrap Model

Regards,

Serge

[LW_10252515]

Hi Serge,

1. RAM: 96GB (ninety-six, not nine point six) - that should do.
2. Inventor 2021, so none of the earlier potential "regressions" should be applicable.
3. Find in Window: Import simply never completes. Inventor import progress hangs at "66%" forever (like in: never ever getting anywhere) while 90% of whatever RAM we assign to the virtual machine are used. Can leave it there for 2 or 128 hours...no change) => Clearly some problem in the importer to not complete but also throw no error. In touch with Autodesk support (as I said before...).
4. Shrinkwrap: requires the supplier side engineer to do extra steps (which they don't like doing of course as from Creo to Creo all is fine... and the Step exchange procedure should be "a piece of cake" normally).  Asking their help step by step of course. Currently waiting to maybe get a parasolid file instead of STEP (or permission to share the trouble STEP with Autodesk support...). Will report back here once we are a step further one way or another. Will keep shrinkwrap in mind though, thanks!

Regards

Lars

[sacquarone]

Hello @LW_10252515 

Sounds like a plan. Thanks a lot to have shared it with us.

Now that I have a better understanding of what you mean when "STEP import attempt fails in INVENTOR" (hang/freeze of Inventor if Step file is large in the scope of a vritualized environment), I have no knowledge in Inventor, but based on what I can find in this area in their Knowledge Base, you may want to try again after having:

• Checked Save Parts (or Components) During Load => See Autodesk Post 1957297

Something to try: In the options dialog, check the "Save Parts During Load" button. As Inventor processes the assembly file it will create part files out of the individual entities in the step file. With this option checked it commits them to disk as it goes instead of trying to keep everything in memory. This has made the difference for me in being able to import large step and iges files. I was able to import a 285 MB iges file this way a few weeks ago.

• Unchecked the Report under Options => See Autodesk Post 3245106

If none of above approaches help, I'm afraid you'll need to wait for a further guidance from Inventor >Technical Support via the ticket you raised with them.

Regards,

Serge

[LW_10252515]

Hi Serge,

thanks for digging that out of the Autodesk forums. Been there, seen that... and here comes the "regression": Recent versions of Inventor (and other of their products, iirc anything >2017) do NOT HAVE that option to Save Parts / Components during load. Gone. Abandoned. Removed. They nowadays (where everyone has trillions of Gigs of RAM) eat ALL into Memory and want to write out ALL once they are finished digesting. Brought that to their attention... so far no sign of them bringing that feature back. What shall I say ...

For the report thing: That's not an option when one uses the GUI import in IV directly; something like that is there if one uses their "task scheduler". No matter whether on or off. If On, it creates a report that says something like: "Eaten up all memory, tasted fine, thanks. Bye bye."

Nope, have to get them those files so they can see where it gets stuck... will be back to report.

[Chris3]

Have you tried a parasolid?

If it helps attached is a 1 inch cube created in Creo 7.0.6 in AP214 and AP242 formats.

Also if you know any students or have kids that want to try Creo out, you could download the free student version and export out some more files to run trials on your end. The only limitation with the student version is that it doesn't intermix with the commercial version.

[LW_10252515]

Hi Martin and Chris,

Thanks for the responses and test files.

- Parasolid: no, not asked for that as a work-around (or rather: better option?) yet. Contractually, we always fix on STEP (as anyone is supposed to be able to handle that). Could be a next step to test that if we can't get it to work with STEP again.

- Test Cubes: those are imported without problems (just like many other steps from various sources).

- I've asked our partners to try the re-import into creo and also for some smaller sub-models to narrow down on the problem. 

Thanks for the hint on the test versions. Hope we get testing from the experts on the other side. They once managed to export similar complex assemblies which we could handle, so it should be a matter of getting the export profile back to what worked. Only I can't tell them what they did when it worked - that's not completely visible from the headers of the step files I believe. My first guess was AP214 vs AP242, but it turned out it wasn't that easy. Anyway, waiting on their response.

I'll be back once I have new information.

[sacquarone]

Hello @LW_10252515 

What do you mean by "fail to import"? Do you mean:

• Import succeeds but open gaps in surfaces (solidification not possible)? => If so playingwith different things in profile (use external accuracy, G2 fix on import for the surfaces, etc) may help

OR

• Import fails with error? => If so, would be helpful to have the exact syntax of error faced upon import attempt to provide later further guidance

OR

• Import attempt leads in an unexpected exit of Creo Parametric? => If so, you should have:
  • a Traceback.log file in working directory. Opening a case to PTC TS and attaching it will allow finding the signature of the trace, and hopefully share further guidance based on this anaylsis
  • a Trail file ending unexpectedly => Opening the trail file in a text editor sometimes help to identify at the very end which was the component which was attempted to be imported when exit occurred, and helps if you have this information, to maybe isolate it (from soft where STEP file starts from, beefore re-export WITHOUT this impacting object) before re-import attempt later in Creo Parametric

Regards,

Serge

[LW_10252515]

Hi Serge,

the import problem is on the Autodesk (and others) software side. We receive Step exports /from/ Creo (where same exports can be re-imported the source company engineer just confirmed). We at my end import them into Autodesk Inventor (or Autocad or Navisworks; or a 3rd party viewer app). All of these imports eat up "unlimited" memory and run "forever" (and unfortunately give no "line XYZ is bad" or anything). I'm of course also in touch on this with Autodesk - but as tons of other Steps we recieve from various sources work just fine for those same import destinations... it's "weird" and not really clear where to start looking.

My hope was that this has been before on your (Creo users) side before.

Cheers

Lars

[sacquarone]

Hello @LW_10252515 

Oh ok. I see. Sorry for my initial understanding. If issue is faced upon Import attempt in a non-PTC software, I'm afraid I won't be in a good position to share further views then. Let's see therefore if others in Community faced similar issues. Good Luck for this!

Regards,

Serge

[KenFarley]

We have had issues with STEP file import into MasterCAM in the past. However, it was not an issue of the import crashing the importing program, but that the geometry was incorrect. revolved type surfaces would be imported as the "other half" of the surface, some surfaces would be untrimmed, etc. We ended up using IGES to transfer the files to the machining programmer, but that's kind of a "I can't get the tractor started so I'm going to use this plow" solution. Sort of.

Maybe the STEP files you're trying to import are suffering from similar "causes" and Autodesk is unable to handle them? Some experiments conducted to try to fix the problem:

(1) Ensuring the accuracy of the model used for the STEP file is absolute with a small (0.000001 inch) accuracy.

(2) Trying different STEP export standards.

(3) Re-building the model in a new part, latest version of Creo, no other "unused features" in the file.

None of these helped. We still output IGES files for the types of parts that give these problems.

We're using Creo 4.0, M120.

[BenLoosli]

Since the files seem to be coming from Creo 7, I wonder if there is something in the changes to handle multi-body that the STEP translators have not taken into account from the Autodesk side?

What version of Inventor are you importing these files into?

Have you imported other Creo 7 files into Inventor before?

Does Autodesk have an updated STEP translator?

[LW_10252515]

Hi Ben.

Inventor 2021.

And yes, we had Creo 7.0.0.0 STEP files (same build code, datecode 2020053 in the STEP headers) initially when the supplier's model wasn't that "mature"/detailed (but already similar in size, several 100MB). Those files imported fine, so the general combination of Creo 7 vs. IV 2021 works. 

And Creo 7 to Navisworks Manage 2020, and to Autocad 2020, and also to that other "Step viewer" we have (not Autodesk based) - all worked well with the same earlier large STEPs.

Something must be different with the more recent model the supplier exports for us. Probably something like mentioned by Ken above.

If no workaround-format (parasolid, iges) works we'll have to get NDAs and stuff in place and get the problem files to Autodesk in the end (will take time, needs NDAs to be signed etc etc...)

Will report on any progress we make one way or another.