MoI discussion forum
MoI discussion forum

Full Version: Solidworks to MOI ???

From: Lewis3D
9 Sep 2021   [#1]
Hi,

I have some models made in SolidWorks and client exported them to *.IGES and *.STEP but in both cases in MOI u have unjointed surfaces visible as small gaps on the edges or even missing pieces of surface.
So when i export them to Polygons (OBJ) it's not usable for render due those gaps/errors and missing pieces.

In SolidWorks models are perfectly aligned and closed (no gaps or missing parts) and they print on 3D printer just fine (printers usually argue if model is not properly closed/watertight)

But for some reason MOI import them with some glitches/errors (sometime i see some trimmed leftovers which are not present in Solidworks.

So My question is what is the best way/workflow to import SolidWorks models in MOI and have nice solids and not just "joined surfaces" which then are not perfectly aligned ?
I tried patching those small errors in MOI manually, but on export i still see those unwelded points on the polygons (since surfaces are not joined properly in import).

Help.

Thanks
From: Michael Gibson
9 Sep 2021   [#2] In reply to [#1]
Hi Lewis, unfortunately transfer between CAD programs is not a simple matter. The difficult area is that CAD programs have somewhat different methods for how they represent trimming boundaries. MoI needs to have a trim boundary where a 3D edge curve does not pass over the "seam" edge of a closed surface, which SolidWorks does allow.

So upon import MoI needs to intersect edges with the seam curve and cut things up. This can be a difficult area to do well especially if there are small edges nearby.

So because of this, CAD transfer is not at all like transfer of say bitmap images or polygon mesh data, where the underlying data is the same and it's just packaged differently. With CAD transfers there is quite a lot of difficult processing that happens to the trim boundaries.

I happen to have been tweaking some of this just recently for MoI v5, if you can send me the models (e-mail to moi@moi3d.com) I can see if my tweaks have improved things for your case or not.

One thing you can try now is to use the CAD Exchanger program as a helper. Try importing your STEP file into CAD Exchanger and saving out from there as a Rhino v5 .3dm file which you can then load into MoI and export polys out from MoI. MoI will not need to split trim boundaries across seams when reading from .3dm format.

- Michael
From: Lewis3D
10 Sep 2021   [#3]
Thanks for info Michael, I checked that CAD converter program, but License is 750$ so kinda steep pricing for just trying to bring data from SW to MOI :).

P.S I sent you problematic file to e-mail

thanks for your time.
From: Frenchy Pilou (PILOU)
10 Sep 2021   [#4] In reply to [#3]
...and you will not 100% sure that result format was good before you make a try! ;)
From: Michael Gibson
10 Sep 2021   [#5] In reply to [#3]
Hi Lewis,

re:
> Thanks for info Michael, I checked that CAD converter program, but License is 750$
> so kinda steep pricing for just trying to bring data from SW to MOI :).

They have a "cloud" based subscription version that's $10 a month and lets you do 20 conversions in that month so that's not expensive if it helps with transfer.

I'd recommend trying that since it's something that you can use right now.

- Michael