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.IGES Geometry Repair

.IGES Geometry Repair

.IGES Geometry Repair

Does anyone know of an available program that repairs .IGES geometry as far as making radii import as actual radii instead of splined curves, parallel faces actually importing as parallel surfaces instead of being at .00000056° angle to each other? Linear elements importing as lines instead of splines?

RE: .IGES Geometry Repair

I would think that's more of an issue with the program you are using to import. This is not a CAD forum, per se; you should probably post this in the forum related to the CAD program you are using to do the import. Alternately, you might want to consider exporting as a STEP file.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
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RE: .IGES Geometry Repair

I can't recommend anything that works directly on IGES files, but, as already mentioned, most high-end CAD systems do provide some sort of 'repair' function for cleaning-up imported data. I know for a fact that NX, from Siemens PLM, has tools to do just that, repair imported data to make it more usable and compatible with downstream applications.

And while this is an old article, it does at least talk about the problems associated with poor models and some of the tools available to fix them, including a discussion of the 'Parasolid Body Shop' tool-kit used by NX (the CAD software product formally known as Unigraphics) as well as several other commercial CAD products:

Your CAD Models Are Busted


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: .IGES Geometry Repair

I would look at the generation end which probably has a setting "export all as splines."

RE: .IGES Geometry Repair

I did not post this in a CAD system specific forum because it mainly is an issue with the accuracy of .iges geometry as compared to .stp, .x_b, and so on. Files I import from the latter two formats are spot-on with surfaces being parallel, perpendicular, and linear elements actually importing as lines. From years of experience, I tend to agree with 3DDave, that this is an issue with the exporting end of the equation.

I was just hoping maybe someone knew of a good neutral geometry repair tool that might be available.

RE: .IGES Geometry Repair

If they're splines, that's should be obvious in the IGES file itself, since it's a text file.

Any line starting with 112, 114, 126, or 128 is specifying a spline. Until you do that minimal check, how do you even know what solution to apply?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: .IGES Geometry Repair

I think the motive to ever create such software disappeared entirely when STEP became popular. IGES is as accurate as required by the generator and the interpreter; there's nothing that is specifically less accurate in the standard for it. The main failing for IGES is that conformity to the standard was mainly handled by allowing every CAD vendor to add their own version of geometry handling to it to the point that IGES compatibility didn't mean much. On top of that vendors would claim IGES support if they handled just one IGES element, such as splines.

I see from an Autodesk help page that their ALIAS IGES support goes to 15 significant digits, so the problem seen isn't a limit in IGES, but the particular implementation.

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