Curtis L. Olson wrote:

> Drew wrote:
>
> >Thanks for the info.
> >
> >FWIW, it probably doesn't have to be that way.  The shading 'math', as
> >you put it, should already be a function of the observer's position,
> >in which case some conditional logic might take care of that.
> >
> >I might try to find the code for this.  In the meantime, I'll just
> >draw two opposite single-sided surfaces.
> >
> >
>
> In opengl, lighting/shading is entirely dependent on the normal you
> define for each vertex.  The orientation of the surface does not factor
> in.  The orientation is used for backface culling, but that's something
> entirely different.
>
> Think about a terrain surface for instance, where the "normal" at any
> given point needs to be some average of the normals of the surrounding
> faces ... perhaps weighted by face size.  If opengl decided to be smart
> and overrule what you've provided for a normal, you wouldn't have the
> level of control you need to do a lot of things.

There are no normal defined in the AC3D file format. Normals are computed by the
plib ac loader.

-Fred

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