I noticed in 3.7 the #declare AmbientLight seems to have no effect. I have used
it and changed the values in wide ranges within the 0-1 value range, and it
seemed to do nothing to brighten up any part of my image.

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"jmichae3" <jmi### [at] yahoocom> wrote:
> I noticed in 3.7 the #declare AmbientLight seems to have no effect. I have used
> it and changed the values in wide ranges within the 0-1 value range, and it
> seemed to do nothing to brighten up any part of my image.

I'm going to guess you are talking about this, which after checking to be sure
does work okay for me:

global_settings
{
    ambient_light <1,1,1>
}

That's the default, and how to specify overall change to all ambient values in
texture finish statements whether or not 'ambient' keyword actually exists.
So this is essentially saying to multiply

finish {ambient 0.1}

by <1,1,1> (since rgb color is allowed). So using <1,0,0> will add a reddish
color to textures.

Won't work on ambient_light keyword as you wrote it. If this isn't the mistake
you have made I'm not sure how else you are trying to apply ambient light.

Also keep in mind that a radiosity {} used in global_settings will disable all
ambient settings. In such case keyword 'emission' will be required instead of
'ambient' in your finish statements.

Hope this was of help to you.

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> I noticed in 3.7 the #declare AmbientLight seems to have no effect. I have used
> it and changed the values in wide ranges within the 0-1 value range, and it
> seemed to do nothing to brighten up any part of my image.
>
>
>

"AmbientLight" is a user defined variable: ALL builtin variables are 
always all lowercase. It can be used for anything, even if it have 
uterly no relation with the name used, like this:

#if(AmbientLight)sphere{0,10 pigment{rgb 1}}#end

Or this:

sphere{1, AmbientLight pigment{rgb<1,0.2,0.3>}finish{ambient 0 diffuse 
0.7 metallic AmbienLight brillance 2*AmbientLight}
}

If you #declare AmbientLight in your scene and don't use that user 
variable, it can't have any effect.

ambient_lihts in the global_settings section is multiplied with the 
ambient component of the finish.
This works ONLY in non-radiosity scenes.

When you render any scene using radiosity, the ambient of ALL finishes 
are turned OFF. You need to use the emission keyword in the finishes 
that you intend to actualy glow and illuminate the surounding surfaces.
"emission" in the finish works similarly to the same for medias.



Alain

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