hello
I'm not a big user, but I just got a job that's going to require a lot of "translation" of CAD files, and the exporter in MoI is top notch..
problem is I get a lot of flipped normals that are impossible to correct in Modo later, and they can actually be seeen in MoI.. How does one correct that?
(this is with latest Beta)

How do you show normals in Moi ?

Else try
Press Tab then Write Flip (capitals or not but without Space) then select Volume, Face then Enter

Hi Mat, that looks like problems in trim boundaries in the import. Different CAD programs can represent trim boundaries in slightly different ways and so there needs to be some processing of them during CAD file translation. Some of the processing can be sensitive to things like badly formed surfaces or some kinds of edges on closed surfaces. So sometimes there needs to be some repair done on the imported geometry.

It's hard to give a recommendation just from looking at a screenshot, is it possible for you to send me the file at moi@moi3.com? If it is large you will probably need to use a file sharing service like Dropbox/One Drive/etc... and send a link to it.

- Michael

Mat I am using Moi in Modo and these kind of issues used to happen to me before I started using LWO as the export format in Moi. Since them Modo imports them perfectly. I suspect this is more a Modo issue than a Moi one as I occasionally see this flipping in Modo modeled meshes for some reason. Mesh clean up doesn't help either.

So if you haven't tried it use the LWO export option.

Nice to see familiar faces here :-)
Pilou tu continues à écumer les forums, ça fait plaisir
Oh hi Mark #theroom

(Mat = Matelot for those who know)

I thought I could tell the flipped faces on export, but actually no.. The LWO export - although better than OBJ - doesn't fix the issue..

Thanks for the offer Michael, i'll send you the file later today..

Le pompon rouge! :)

Hi Mat, I got your model and sent you a reply.

There are a lot of issues with the model - it appears to have gaps of up to 0.02 units between many pieces so it's not going to be able to be cleanly joined.

The main way to avoid flipped polys is to have a well formed model that has every edge joined between 2 surfaces. If you have 2 surfaces just sitting next to each other but not actually having shared joined edges then that's what can easily result in different polygon normal directions between them.

When you've got a clean model with all edges joined between 2 surfaces, the whole piece will then have a consistent normal direction.

Unfortunately in your case here the model data being so inaccurate it's going to be hard to make it into a well formed result.

I also tested loading your file into Rhino and got the same problems there, with 3796 naked edges after attempting to join it all together.

Probably the first thing I'd recommend is to try and get the model in STEP (.stp) format instead of IGES. STEP format can contain edge joining information inside of it and so that may come across better.

The model quality seems very poor in general though, I just found another area with a gap of 0.07 units between surfaces.

You're not going to be able to get nice clean high qualiity output on messy inaccurate input basically.

- Michael

Hi MAT, I examined the model some more and found some areas with very large gaps between surfaces like around 0.07 units. You just aren't going to be able to get a high quality mesh automatically generated from such a messy pile of individual surfaces.

But using STEP format instead of IGES is worth a try.

- Michael

Thanks Michael, I brought up the issue to my client