Face in respect to 2D curve (or fin)

Rhino Developer
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Ive read the following in the Rhino documentation in Brep Loop & Edge Directions

“loops are always oriented so that the active region of the face is to the left of the 2D curve.”

BUT is the face to the left of the 2D curve when looking down the face normal or looking down the surface normal. Obviously the face and surface normals don’t have to be in same direction, so it’s quite important to know

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According to the docs “the loops are always oriented so that the active region of the face is to the left of the 2D curve.”

Is this while looking down the face normal or surface normal? If they are not oriented in the same way, this distinction matters

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Hi Jack -
I’ve merged this last post with your previous thread - please don’t double-post.

I’m of not much use answering developers questions, but…

What’s the difference between the face and the surface?
And, as far as I understand the quoted description, this is not while looking down any normal but while traveling along the curve.
-wim

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