> Anton Sherwood wrote:
> > > Is there an easy way to approximate a minimal surface (soap film)
> > > spanning a skew polygon?
> >
> > Afterthought: Failing that, if I slice it into flat triangles,
> > is there a trick with "normal" to hide the facets?

Jerry Anning wrote:
> If that is good enough, just use smooth_triangles.  Calculate the
> normals at each junction by averaging the normals of the triangles
> that meet there.  (Get those normals by vcrossing any two sides of
> each triangle). 

Or, for my purpose: use the cross product of two adjacent sides of the
skeleton polygon.  (I may want an extra point in the center, whose
normal is the average of the corner normals.)

Thanks everybody, this is exactly what I need - I just didn't rtfm
far enough.  (smooth_triangles are not covered in the tutorial.)

Does the magnitude of the normal vector have any effect?
What if its sign (relative to the surface) changes?

-- 
"How'd ya like to climb this high without no mountain?" --Porky Pine
Anton Sherwood   *\\*   +1 415 267 0685   *\\*   Ant### [at] jpsnet

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