Hi Dan,

I also work with importing large step/igs automotive files, and would like to improve the process.  Here are a few techniques - none of which are perfect solutions, but sometimes they matter for a particular situation.  Before starting - what is considered a big step/igs file?  for me 100mb is about the starting point of "big", and when it gets 200-300mb+, then it gets rather painful.

1) For SW2018, there is now the "3D Interconnect" function.  This function has no value for me whatsoever, but if this is turned on or off sometimes affects the viability of importing a particular file.  There have been cases where an import is successful only with interconnect turned on, and vice-versa.

2) At times Grabcad (free online "workbench" function) can be helpful.  I've uploaded various files (including native Catia/UG) and then grabcad can download as step, parasolid, or igs.  Most often parasolid is quickest/nicest to use - but not always, sometimes grabcad fails to output x_t, and sometimes they do not import well.

3) Tetra 4D is used as a translation tool also.  Cost is approx. $500 (may be a 30 day free trial?), it works inside of Adobe Acrobat pro, so that license is needed also.  It's crazy fast to read a file in, and it will export to step and x_t.  For situations with many step/igs files, it is faster to open in Tetra and output x_t, which then import fairly quickly into SW.

4) Another factor for importing into SW is whether to import free curves and sketches.  Sometimes this makes an import fail, although there are times when it is nice/necessary to have sketches import.  I usually try with sketches on first.

5) I almost never try to diagnose/repair imported geometry, it is simply waaaaay too slow in many cases.  But occasionally it is helpful if there are surface defects which matter down the road (depending on what is done with the imported geometry)

6) Imports often come in as assemblies, often these are saved as part files because they seem to run faster than the assemblies.  But not always.  And depending on what is done with the imported data, it may be necessary/preferred to save as an assembly.  But be prepared for cumbersome assemblies with sometimes thousands of components, sometimes each surface/face becomes an individual file.

General procedure is as follows:

a) If <100-150mb, try to import direct into SW with interconnect and sketches both on.  If that produces a files that looks right and loads (the saved SW file reloading time) in 20-30 seconds or less - good to go.  If the import goes over about 30 minutes, abort and go to step 2.

b) For larger files, import to Tetra and export x_t, then bring into SW per step 1.

c) If the import into SW does not give usable result, try with interconnect turned off.   If that also does not work, then turn off sketches and try again.

d) If still failing to give usable results, then try step out of Tetra, and/or grabcad export to x_t, step, and/or igs.

Sorry to not have anything definitive, but maybe some of this will be helpful in some manner.  And thanks for posting, if anyone else has tips and/or third party options that help would be great. 

Use those ones:

Datakit for Solidworks

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Transmagic for Solidworks

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