STEP compression format .stpZ support

[easyw-fc]

Hi,
I've just started to add a support for STEP File Compression for FreeCAD as it can be found on many commercial sw.

The reference is this documentation at
STEP file compression format

This FC Mod addon
https://github.com/easyw/stpZ
is able to read and write STEP files using the compressed STEP file extension .stpZ
The level of compression can be up to 10 times.

I tested the Import/Export feature with a Catia stpZ file found online:
Bracket.stpZ.zip
The file 'Bracket.stpZ.zip' has to be unzipped to 'Bracket.stpZ' to test the Importing.

I have also provided a sample of a hierarchy file here
as1-oc-214.stp uncompressed file size: 432K
as1-oc-214.stpZ compressed file size: 32K

Would someone please test to import and export some file generated by some commercial sw to see if everything is working as needed?

If this can be of some interest, I could ask to merge the Import/Export Mod to the main branch.

Maurice

[Marco_T]

I've just started to add a support for STEP File Compression for FreeCAD as it can be found on many commercial sw.

Hi Maurice,
I don't use this file format but I think this import/export feature is very useful to improve the FreeCAD capabilities.
FC will became a real "swiss knife" in terms of data interchange.
Thanks for your effort!

--
Marco_T

[jmaustpc]

If this can be of some interest, I could ask to merge the Import/Export Mod to the main branch.

Maurice

Hi Maurice
Once you are happy with it, I agree that this should be in master. Might be something worth getting into 0.17, if doing so is not too complex/difficult.

Jim

[easyw-fc]

Hi Maurice,
I don't use this file format but I think this import/export feature is very useful to improve the FreeCAD capabilities.
FC will became a real "swiss knife" in terms of data interchange.
Thanks for your effort!

Hi Marco_T
I know this is a format now widely used because it seems that only Catia and NX are taking in care of it, but it would be an other feature for the FC "swiss knife"
At the same time I'm starting to use it just to save space on my STEP library... I can just open a stpZ file instead of a manually zipped one in just one click, and then save it back without the need to re-zip it manually.

Hi Maurice
Once you are happy with it, I agree that this should be in master. Might be something worth getting into 0.17, if doing so is not too complex/difficult.
Jim

Hi Jim,
the stpZ importer/exporter is quite simple and it is working fine now, the only issue I have ATM is with utf-8 file names, because FC release of gzip doesn't handle correctly utf-8 file names.

I'm working on it.

I'm adding also a picture of the stpZ philosophy as in the CAX-if doc

stpZ-sample.png (52.45 KiB) Viewed 6427 times

stpZ-benefits.png (56.92 KiB) Viewed 6426 times

[easyw-fc]

It has been merged
https://github.com/FreeCAD/FreeCAD/pull/1272

[Kunda1]

OT here but relevant, just riffing an idea here.. but I was wondering if somehow we could rig phpbb do automatically compress step files this way when they get uploaded to the forum server. thoughts?

[jmaustpc]

Hi Jim,
the stpZ importer/exporter

According to your posts and this document I found (I am sure its the same document as the one you where referencing)
https://www.cax-if.org/documents/rec_pr ... on_v12.pdf

The file extension is ".stpZ" not ".stpz", that is the "Z" is supposed to be capitalised. I am not sure if that is a good idea since I don't know if all O/Ses will accept a capitalised file extension. PHPBB certainly dosen't. I just added it as an allowed file type in these forums but even though I used a capitalised "Z" PHPBB converted it top lower case.

Obviously it was not you who decided on the file extension.

Jim

[easyw-fc]

Hi Jim,
the stpZ importer/exporter

According to your posts and this document I found (I am sure its the same document as the one you where referencing)
https://www.cax-if.org/documents/rec_pr ... on_v12.pdf

The file extension is ".stpZ" not ".stpz", that is the "Z" is supposed to be capitalised. I am not sure if that is a good idea since I don't know if all O/Ses will accept a capitalised file extension. PHPBB certainly dosen't. I just added it as an allowed file type in these forums but even though I used a capitalised "Z" PHPBB converted it top lower case.

Obviously it was not you who decided on the file extension.

Jim

stpZ is most supported by Catia and NX ... so I think is mainly Windoz os which is not case sensitive ...
Anyway in the stpZ file importer/exporter I used both 'stpZ' and 'stpz' file extension

Now we have Catia, NX and FreeCAD