RC: Evaluate Surface

Rhino Developer
1

Hi,

I need to evaluate normal at (u,v) coordinates for surface. I am using Surface.NormalAt().
However I noticed that direction of the Normal is not changing when ‘flipping’ surface via normal Rhino Command ‘Direction’.
Any hint how to correlate direction of the Normal with direction shown via ‘Direction’ command in Rhino?

Thanks,
Dmitriy

2

Hi Dmitry

Check BrepFace.OrientationIsReversed.

http://developer.rhino3d.com/api/RhinoCommon/html/P_Rhino_Geometry_BrepFace_OrientationIsReversed.htm

It believe flipping the surface sets this flag and does not change the surface structure.

-Willem

3

Thanks @Willem

Exactly what I was looking for.
Works perfectly!

Thx,
Dmitriy

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