Problem between BrepFace and Brep

I have got a very big problem. I need the orientation of a BrepFace through a Brep.
When I transform BreapFace to Brep with method “toBrep()”, I lose that information.

I have a FaceBrep that returns true if I use face.OrientationIsReversed, but BrepFace.ToBrep().Faces.First().OrientationIsReversed returns false.

How I can resolve this issue??

Hi Hector,

I am confused, you are you using the ToBrep() method?.

If you have a BrepFace and you have it’s orientation, then just do this:

BrepFace face = ...;
var reversed = face.OrientationIsReversed;

– Dale

Hello Dale,

I’ve already contempled this situation, but I can’t use it.
My code is working with Brep’s. And I need to get that orientation from one Brep.

Any other idea?

Thanks for your fast answer,

If you have the Brep, you can get the orientation of the face like this:

var rev = brep.Faces[face.FaceIndex].OrientationIsReversed;

– Dale

There is the problem.

Just this is wrong:

If I get the orientation from the BrepFace, it returns one value.
Then, I convert this Face in Brep.
Later, I get the orientation through “brep.Faces.FirstOrDefault().OrientationIsReversed” that is the same that “brep.Faces[0].OrientationIsReversed” and it returns other different value.


Yes, of course, you may get a different value as you’ve created a new Brep…

OK. I’ll have to research other solution.

Thanks anyway,

Hi Hector,

How about the BrepFace.DuplicateFace Method? Maybe that will keep the reversed flag from the input face?


Hi Willem,

I’ve tested and it works!! It’s perfect for my project. Thank you very much!!

Best regards,

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