POV-Ray : Newsgroups : povray.general : Mirrorball Server Time
17 Nov 2024 01:13:35 EST (-0500)
  Mirrorball (Message 1 to 2 of 2)  
From: Tone Duff
Subject: Mirrorball
Date: 8 Jul 2003 05:46:24
Message: <pan.2003.07.08.09.46.23.8506@careless.net>
Ok,
	Simple enough model in theory but in doing some dimple tests
I've been unable to get reflections coming off my object. At
the moment I have a simple cube with a reflectivity of 1.0. At
this I shine colored lights (a light source inside a tube). I
would have assume that I would get a colored spot on the floor (plane)
where the colored light was reflected. But I can't seem to get it 
to work.

/*
** Rudimentry mirror ball
*/
                                                                                
                                                                                
box {
        <-100,0,-100>
        <100,1000,100>
        pigment { color White }
        finish { Mirror }
        rotate y*clock*180
}


Is there something wrong with this approach?

-- 
ryan@careless dot net


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From: Tim Nikias v2 0
Subject: Re: Mirrorball
Date: 8 Jul 2003 06:03:58
Message: <3f0a970e@news.povray.org>
The problem is the raytracing-approach. If the
raytracer would want to check if a lightray is
being reflected to the actual pixel in question (or
the surface which the pixel will show, to be more
precise), you'd have to wait for decades for a
single line to finish.

That's what Photon-Lightmapping has been
coded. What it does is shoot tiny, spherical
lightsources (this is just an asymptotic description,
don't nail me on facts) at reflective (targeted) objects,
off of which they'll get reflected and spread into the
scene.

To activate this, do the following:
global_settings{
 photons{ //This switches photons on
 spacing .05 //raise for less, lower for more detail
 autostop 0 //look at docs for this one
 }
}

And the object you want to reflect light off
(the discoball), do like this:
sphere{... material{...}
 photons{target reflection on refraction on collect off}
}

You may also look at the docs for that.

Hope this gets you started.

Regards,
Tim



-- 
Tim Nikias v2.0
Homepage: http://www.digitaltwilight.de/no_lights


> Ok,
> Simple enough model in theory but in doing some dimple tests
> I've been unable to get reflections coming off my object. At
> the moment I have a simple cube with a reflectivity of 1.0. At
> this I shine colored lights (a light source inside a tube). I
> would have assume that I would get a colored spot on the floor (plane)
> where the colored light was reflected. But I can't seem to get it
> to work.
>
> /*
> ** Rudimentry mirror ball
> */
>
>
> box {
>         <-100,0,-100>
>         <100,1000,100>
>         pigment { color White }
>         finish { Mirror }
>         rotate y*clock*180
> }
>
>
> Is there something wrong with this approach?
>
> -- 
> ryan@careless dot net


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