Jim Kress wrote:
> 
> I have a closed, 3D surface that is represented by a set of triangles.  
[SNIP]

> This is all the data I am given.  I am not given any data about which side
> of the triangle I am looking at.  I am not given any data about the winding
> of the vertices.
> 
> What I want to do is make sure all triangle normals are pointing out of the
> surface and all triangles are wound counter-clockwise.

See my other answer for the details.
Just choose any arbitrary location (possibly not right on the mesh, but even inside
is fine).
If the sign does not please you, just invert two vertices of the triangle.

Please note that you are not provided with the normal, so your first part looks
caduc (unless you exactly know how the normal is going to be computed).
The calculation of a normal always gives the same line, but the orientation
of the vector depends on the implementation. Your second part seems to imply
that you have such (implicit) knowledge about the internal computation.

> Is that a better statement of my problem?  Any help you can provide would be
> appreciated.

Just for curiosity, why do you need to do that ?


-- 
Non Sine Numine
http://grimbert.cjb.net/
Etiquette is for those with no breeding;
fashion for those with no taste.

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