Reading and writing older versions

Sean,

What they have no control over (or very little) is Parasolid. Parasolid
isn't backward compatible, and every new release of SW uses a newer version
than the previous.

Shape Data gives them compiled libraries, not source code.

Mark

 

John,

Oooooooooooooo,,,,, it's a conspiracy... gimme a break.

I haven't called anyone ignorant, all I've asked you to do is really think
about it. Another example. SW has changed it's surfacing algorithms in every
releas since 2001+. I have several product models that were done in 2001+
that I can't even bring "FORWARD". Why ? because the surfaces change shape,
some have failed features asa result, and "ALL" of them no longer match the
very expensive production injection molds.

Can you imagine trying to go backwards to a version that didn't support
things like local curvature and tangency control. The resulting mess would
be usless.

I have a feeling that maybe you just do prismatic mechanical stuff. Nothing
wrong with that, but it doesn't give you a very good view of the larger
picture.


Regards


Mark

 

....

I think this reaction is kind of severe. It's true that no one likes
half baked features, I'm the first to jump on that wagon too, but the
translation issue has never been a 100% success. IGES has been half
baked for a long, long time, but people still use it even though there
are better alternatives. The ProE translator is far from perfect too,
but if I have to rebuild a ProE part, I'd rather start with maybe 80% of
the sketches than nothing.

I suppose if you're so down on things that don't work perfectly, you've
never used FeatureWorks. FeatureWorks can strip out the features it can
recognize and leave the rest as a solid imported blob with parametric
features around it. I'm not suggesting that anyone should use FW to
translate new SW files, but I don't see why it wouldn't be technically
feasible for a program that looks at the instructions to make the
features to recreate them rather than looking at the geometry itself,
and use the parasolid data for features that don't exist in the older
version. You'd wind up with a blob that represents the shape feature,
and paremetrics for other things that existed in that version.

http:\\baren-boym.com\ExchWorks14Demo.zip

Link is still active after a couple years. The help file is in Russian,
which, maybe I'm wrong about this, but isn't really helpful. Anyway,
Barenboym started the project and seems to have dropped it for some
reason. I know we traded a couple of emails, and the intention was to
go forward with more feature types. This version I think did extrudes,
revolves and simple fillets.

Technically difficult? Probably. Impossible? No.
Financially feasible? Probably not.

Financially for SW it would be a big loser because obviously fewer
people upgrade if they're not forced. I don't believe SW will ever
provide this. A 3rd party provider like Barenboym would be the folks
who would have to do it.

There's no way of knowing, but someone might have exerted some pressure
to stop that project too... You can get to Framingham from Concord in
about 30 minutes.

I don't think it will ever become a reality, but I think it's definitely
doable.

Matt

 

John,

Aren't you looking at it backwards ??

SW version based on PS14 shouldn't be expected to read a SW file based on
PS15.

Mark

 

I think it was promised at SWW two years ago. If SW does it first just
think what it will do to Inventor with all those giveaway seats in
circulation.

 

Save as an older version of ParaSolid & then open it
up in an older version of SW & see ....

You just translated to the older SW version, right?

 

I just ran a test using the ExchangeWorks v.1.4 conversion utility that
Baren-Boym was developing. I re-confirmed my earlier findings that even the
simplest geometry doesn't convert accurately.

I modeled a simple 1.0" diameter cylinder and saved it as a 3XF format file
using ExchangeWorks. I then imported the 3XF file back into SolidWorks
using ExchangeWorks. A quick examination of the dimensions showed that the
diameter had been changed to 0.99999995". Not a significant difference, but
certainly nothing to ignore.

Autodesk attempted to address this type of issue with their "proxy object"
approach. It would be kind to say it doesn't work very well.

While backwards translation would help me in some cases, I want it to be
robust, and allow for round-tripping without data loss. What many users
have suggested in this post would alter the file to such an extent that
design intent and future editing would be negatively compromised.

John

 

Interesting Topic - personally I'm with the 'dumb' customers !
The solidworks 'apologists' are probably the same folk who say - 'hey
.... its real hard for (poor) software co's to fully debug their
software before releasing it - give them a break'. .... give ME a break
!!!!

As a engineer/designer i am continuously being challenged to make
improvements for end users - and thats what I try and do, willingly and
generally with success.

The thing about this issue is its a 'double whammy' .... some form of
backward compatibility would not only would it allow sharing with
others who have not upgraded at precisely the same time, ..............
BUT ALSO, would neatly side-step the problem of flacky early release
new versions - with as 'save as' previous version these REAL problems
we have to work around are ... history.