"Warp" <war### [at] tagpovrayorg> wrote in message
news:3bc5676c@news.povray.org...
>
>   The problem with reflection is that it's linear. This means that if you
> have a reflection 0.1, then *everything* which is reflected is multiplied
> by 0.1. This means that a "light source" (with a looks_like object) of
> color <1,1,1> will be multiplied by 0.1, so only <.1,.1,.1> is reflected.
>   However, in realitity bright light sources are reflected in polished
surfaces
> more than dim light. This is exactly what the specular lighting model
tries
> to simulate (and succeeds a lot better than reflection alone).

Keyword exponent in a reflection statement is the new way of saying
reflection_exponent as was used in v3.1, and it'll do a similar effect as
mentioned by Warp.  Value less than 1.0 will darken all but the brightest
scene objects.

Of course to use looks_like and have a reasonable highlight on the subject
object you'd want to use specular highlighting in the finish of a clear
object acting as the light source in order to get a softened fake highlight.
Else all you get is the directly reflected object outline instead.

That's what Warp was describing is different from the reality if you try
reflection alone.

>   One idea: I haven't tested what happens if your looks_like object is
> colored with <10,10,10> (while the reflecting surface has a reflection
0.1).

It does contribute more to the reflection.  Having checked, high diffuse
creates about the best faked highlighting, kind of figured it might.
Ambient and color are too solid to be useful.  Problem with that idea though
is how you need some non-transparent color for diffuse to do anything which
then can show up where not wanted.

Bob H.

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