Good. I'll get going with the V3 beta. I assume that it won't affect my reliable v2.52, right?

With ViaCAD, I did enable the STEP import option to "Stitch Surfaces Into Solid". Perhaps that helped with the dodgy geometry?

And thanks for the email address. I'll see about getting you and intact STEP file for your evaluation purposes.

The import scale is a weird one. I had no idea that it was that size in MOI, and that ~4inches is right in the ballpark. Now things are even more confusing.
My reason for assuming the scales are off, is because I have a set of reliable numbers I use (for instance) for adding small bevels to certain hard edges on the products. I do enough of these products were I can count on those numbers to look right. Normally, I would use something like .1 or .25. Now, that has always worked with the ProE STEP exports I get, and they are the same products as the ones I am also now receiving from NX. But with the NX STEP file, I had to back WAY off to .001 to approximate the same edge profile.
So, I don't know what to do to figure this out.

Hi sneather,

> I assume that it won't affect my reliable v2.52, right?

Yeah it should not have any effect on v2.52 .


> With ViaCAD, I did enable the STEP import option to "Stitch Surfaces Into Solid".
> Perhaps that helped with the dodgy geometry?

Hmmm, probably that particular setting doesn't control that. Some other programs based on the same library that ViaCAD uses have options for turning on or off "healing" of the imported geometry. I thought ViaCAD might too but I see it doesn't. Maybe ViaCAD just has that permanently turned on.


> But with the NX STEP file, I had to back WAY off to .001 to approximate
> the same edge profile.
> So, I don't know what to do to figure this out.

I guess I'd need to know more about which specific edge you're trying to bevel in each case to be able to give you more information about this one... Are you sure you're not trying to bevel an edge that is just longer and on the outside of the object in one case but then doing one that is much smaller on some little portion of one of the inside details in the second case?

- Michael

"""""""The import scale is a weird one. I had no idea that it was that size in MOI, and that ~4inches is right in the ballpark. Now things are even more confusing."""""""""""""

You might assume that the NX step file is being written as "MM" instead of inches.

Hi sneather,

I've been using NX (unigraphics) professionally for the past 11 years and MoI at home since V1, if you like PM me, we could organise for me to have a look at the file in question, confidentiality assured of course, I can run a few checks in NX to check the geometry to see if it's a modelling problem or a translation problem and maybe work out a solution or work around.

Cheers
Danny

Thanks BurrMan. Do you know whether there is a separate units option in the STEP export process from NX?
Again, I trust the designer when he says that they work in inches, inside NX. So maybe it's an export-related issue?

Thank you, DannyT. That's quite generous of you.

As of yesterday, I'm on a crash course, trying to learn the basics of ViaCAD Pro for Mac. It was recommended that I might try that, in order to see whether it might be able to process the STEP file better. And it does. No geometry issues, and it even seems to have slightly better structure, too. I have no idea why it would be that much different from MOI, but it seems to be so far.

I also installed the V3 MOI Beta. Michael G - that DID seem to fix most of the bad geometry. There is still one odd spot, where the surface has a hole. But it's much better than what happens when I bring it in with V2.52.

I have a suspicion, that I might just need to use both MOI and ViaCAD in my model prep pipeline. I'm becoming extremely comfortable with working in MOI (and I LOVE this fantastic help forum - simply nothing else like this!) so I might try processing the STEP files in ViaCAD, and then doing the rest of my work in MOI. Plus, ViaCAD seems to be lacking any control over the final .OBJ output (which is crucial) and both MOI and Rhino have fantastic mesh generators.

Hey sneather,
"""""""""""Do you know whether there is a separate units option in the STEP export process from NX?
Again, I trust the designer when he says that they work in inches, inside NX. So maybe it's an export-related issue?""""""""""

I dont think so, but NX is a higher end modeler and has several different ways it handles units. The only real way to track it down would be to get the nx file to someone like Danny, who could then review it's particular setup. There should be no problen with working directly from NX to MoI.

I would be certain the model looks good in NX. NX using the parasolids kernel, will have several different means to construct geometry in "difficult" areas. Like the area where you are showing a problem, looks like one of those areas where the filleter crashes into and goes beyond itself (this would fail with MoI's filleter), but generates a result. The translation of that area just isnt going through the 2 translators, nx's export and moi's import, as intended.

My suggestion would be to ask the designer to provide you with a few of the formats that MoI handles when sending the models over. Package up a STEP, IGES and a SAT. Then, you can find the one that imports the parts as intended. You will find that different models (areas of difficult surface generation) will come through in different formats. Try an iges, the most generic surface translator.

<<<<The import scale is a weird one. I had no idea that it was that size in MOI, and that ~4inches is right in the ballpark. Now things are even more confusing.
My reason for assuming the scales are off, is because I have a set of reliable numbers I use (for instance) for adding small bevels to certain hard edges on the products. I do enough of these products were I can count on those numbers to look right. Normally, I would use something like .1 or .25. Now, that has always worked with the ProE STEP exports I get, and they are the same products as the ones I am also now receiving from NX. But with the NX STEP file, I had to back WAY off to .001 to approximate the same edge profile.
So, I don't know what to do to figure this out.>>>>

 

Sounds like your Pro-E files were in MM and your new files from NX are in inches. A .25 fillet on a 4" part is rather large. A .25 fillet on a 102 mm part sounds like what you were doing. I don't think any weird scaling is going on with any of your files. Measure some of your old files. A .001 fillet is very close to a 1/4 of a mm.

I get quite a few files from Pro-e, solidworks, inventor etc. and all of them usually need a few things touched up. Things like the corners of fillets bad trims etc I don't think there is a perfect solution. Nothing a few rail sweeps wont fix. I would ask for .step and .iges files and you should have your bases covered.

P.S. I have played with via cad a few times and it would crash a bunch of larger CAD files. I my opinion MOI is much better. Every once in a while I use a open source program called free cad. I seems to have a very robust .iges and .stp importer and may be worth a try on some troublesome files.


-Shane