Hello! I've been wanting to learn MOI for a while but just finally pulled the trigger because I've read that it can be used to convert files and its output meshes are second to none. I wholeheartedly agree, however I'm having some pretty significant issues. I've tried SLDPRT -> STEP (solidworks) -> OBJ (MoI) and SLDPRT -> IGES (solidworks) -> OBJ (MOI) but I have the same problem in either case. Edges don't align with each other and polygons are missing. This is apparent even before converting it to OBJ. I can open the STEP file in other programs to see that there aren't any geometrical issues but for some reason I can't get MoI to cooperate. Any help would be greatly appreciated! Thanks!

Hi Eric, can you please e-mail the STEP file generated from SolidWorks to me at moi@moi3d.com so I can take a look?

Thanks, - Michael

Just sent it to you, thanks!

Hi Eric, thanks for sending the file. I tested it with Rhino and ViaCAD and saw the same problems in both of those as what you show in MoI.

The main thing that could cause those kinds of gaps to open up is if SolidWorks thinks the surfaces in those areas are planes yet the trimming boundaries around them are some fairly large (larger than an expected tolerance amount) away from that plane.

You might try the "Check entity" command in SolidWorks:
http://help.solidworks.com/2018/english/solidworks/sldworks/hidd_check_entity.htm
and see if it complains about any way out of tolerance trimming edges.

Another thing you can try is a setting for IGES export in SolidWorks:
http://help.solidworks.com/2018/english/SolidWorks/sldworks/hidd_export_options_iges.htm
Try the option for using “Trimmed Surface (type 144)” and maybe "Use high trim curve accuracy".

Also for IGES using type 144 trimmed surfaces maybe only export one solid at a time, not multiple separate objects in one single file because they will be all individual surfaces and if surfaces from 2 parts touch each other they can interfere with each other for getting joined together.

Does that make any difference? Also does re-importing the IGES with type 144 trimmed surfaces back into SolidWorks give the same gaps? If so then the problem is likely that it's a badly formed model in SolidWorks to start with, with trim edges way out of tolerance from their plane surface.

- Michael

To add to what Michael said, you should turn on "verification on rebuild". This will help to catch some errors early on to avoid bigger problems later.
http://help.solidworks.com/2018/english/solidworks/sldworks/t_Checking_Model_Geometry.htm

That's really helpful! I realized that both of the places in your screenshots are places I used the same tool to fix the geometry. What happened is that I used the delete and patch tool in Solidworks to merge all of the corners in those locations. That's apparently what the real geometry looked like before I did that. Solidworks showed it the way I wanted it to look and so did those other programs but apparently that geometry was still there and only MOI, Rhino, and ViaCAD could see it. I got rid of that operation and now it exports without issue! I still need to clean up those corners but it'll be easier to do that in Houdini after its been converted to OBJ. Thank you!

That is going to be so helpful going forward. Thank you!

Houdini has Nurbs ?