I have a closed, 3D surface that is represented by a set of triangles.  I
have a list of the vertices of every triangle (i.e. the Cartesian
coordinates of each vertex) and I have a list of integers (grouped in
threes) where each group of integers gives me the number of each vertex in a
triangle.

For example:

vertex 1 is 1.0,2.0,3.0
vertex 2 is 2.0,3.0,4.0
vertex 3 is 4.0,5.0,6.0
vertex 4 is 5.0,6.0,7.0

Triangle 1 is made up of vertices 1,2,3
Triangle 2 is made up of vertices 1,2,4

The data I am given is:

1.0,2.0,3.0
2.0,3.0,4.0
4.0,5.0,6.0
5.0,6.0,7.0
1,2,3
1,2,4

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.

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

Jim

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