John M. Dlugosz wrote:
> 
> Mark Wagner <mar### [at] gtenet> wrote in message
> news:37ccb22d@news.povray.org...
> > Try using radiosity -- it has a much greater effect in this situation than
> > you'd expect.
> 
> I did try it, briefly.  I'm sure I could twiddle the parameters a LOT, but
> off hand I saw that it didn't illuminate metal the way I wanted.  When
> backlit by the key light, it looked just like a high ambiant -- no curves or
> shape visible.

Some 3D effects look best when animated (though you wouldn't necessarily
think so offhand); your brain uses the movement to see how an object's
appearance reacts to the objects around it. Metal and glass are probably
the best examples of this, as movement helps you perceive reflection and
refraction. (The ability to see different sides of an object, or to
judge its distance relative to other objects, also require movement, but
are based on perspective rather than interactivity.)

Of course, you don't sound like you're planning to animate this.

The next thing, then, would be to take a careful look at exactly what
you're illuminating, and how. With some thought and tweaking, you can
probably get it to look how you want. (I can't offer any more specific
suggestions, since I have almost no idea what the scene's supposed to
look like or what's in it.. I must have missed the first post.)

> Physically, the other end of the room is a light source, and lambert shading
> applies.  And in the case of metal, more spectral highlights are noticable
> as well.  Turning up ambiant light levels didn't give the objects any
> =shape=, and my try at using radiosity was no different.  Would adjusting
> the parameters help with that specific effect?

Ambient lighting (effectively) hits an object from every angle, so no,
obviously it wouldn't produce shadows that would help define the shape
of the object. In fact, it would do the opposite, by fading or
eliminating those shadows.

> More than once I've wished that it was possible to declare that specific
> light sources interact only with specific objects.

I don't think you can do this.. but in some cases, a carefully-placed
spotlight will do the trick, similar to the way that photographers use
reflectors to subtly illuminate a model's face (if you've seen an
outdoor photo shoot, you know what I'm getting at).

-Xplo

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