Hi. I don't know anything about this attenaution patch, or what it is
exactly for. I've just seen SamuelT. do some real nice stuff with it. I
decided to try it myself and to my surprise, this happened:

camera {location <1,2,-3>*10 look_at 0}
light_source {y*10 2}
plane {y,0 pigment {rgb .5}}
sphere {y*6,4 pigment {rgbf 1} interior {fade_power 2 fade_distance 4
fade_color rgb <1,3,2>}}

Try it for yourselves... Is this a bug or some feature of the attenuation?
Did I do something wrong, perhaps?

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Hmm, that is indeed a strange thing. When I raised the light_source, the dots
disappeared. Even if I put y*10.000001 for the light_source. Anything over ten
unit high makes the dots go away. Looks like a bug to me. You scene is neat,
by the way. The glow (after changing the light_source) is cool.

I just tried lower numbers and they make the dots go away too. Maybe 10 is the
magic number?

TonyB wrote:

> Hi. I don't know anything about this attenaution patch, or what it is
> exactly for. I've just seen SamuelT. do some real nice stuff with it. I
> decided to try it myself and to my surprise, this happened:
>
> camera {location <1,2,-3>*10 look_at 0}
> light_source {y*10 2}
> plane {y,0 pigment {rgb .5}}
> sphere {y*6,4 pigment {rgbf 1} interior {fade_power 2 fade_distance 4
> fade_color rgb <1,3,2>}}
>
> Try it for yourselves... Is this a bug or some feature of the attenuation?
> Did I do something wrong, perhaps?

--
Samuel Benge

STB### [at] aolcom

"And you can fly
 High as a kite if you want to
 Faster than light if you want to
 Speeding through the universe
 Thinking is the best way to travel"

          -The Best Way to Travel, The Moody Blues

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In article <381CB4B0.E9E7B992@aol.com> , "SamuelT." <STB### [at] aolcom> wrote:

> Hmm, that is indeed a strange thing. When I raised the light_source, the dots
> disappeared. Even if I put y*10.000001 for the light_source. Anything over ten
> unit high makes the dots go away. Looks like a bug to me. You scene is neat,
> by the way. The glow (after changing the light_source) is cool.
>
> I just tried lower numbers and they make the dots go away too. Maybe 10 is the
> magic number?

Depending on precision, the light will be inside or outside the sphere, that
is why moving it a bit removes the effect.


     Thorsten


____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org

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Ha ha ha! Funny me..... I hadn't inspected the code that closely. Sure enough, the
light was directly on the edge of the sphere....

Thorsten Froehlich wrote:

> In article <381CB4B0.E9E7B992@aol.com> , "SamuelT." <STB### [at] aolcom> wrote:
>
> > Hmm, that is indeed a strange thing. When I raised the light_source, the dots
> > disappeared. Even if I put y*10.000001 for the light_source. Anything over ten
> > unit high makes the dots go away. Looks like a bug to me. You scene is neat,
> > by the way. The glow (after changing the light_source) is cool.
> >
> > I just tried lower numbers and they make the dots go away too. Maybe 10 is the
> > magic number?
>
> Depending on precision, the light will be inside or outside the sphere, that
> is why moving it a bit removes the effect.
>
>      Thorsten
>
> ____________________________________________________
> Thorsten Froehlich
> e-mail: mac### [at] povrayorg
>
> I am a member of the POV-Ray Team.
> Visit POV-Ray on the web: http://mac.povray.org

--
Samuel Benge

STB### [at] aolcom

"And you can fly
 High as a kite if you want to
 Faster than light if you want to
 Speeding through the universe
 Thinking is the best way to travel"

          -The Best Way to Travel, The Moody Blues

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And why does this matter?

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TonyB wrote:
> 
> And why does this matter?

 I imagine the dots that are being seen are becuase POV-Ray is treating it
like a coincident surfaces problem where it cannot tell if the light is
inside the surface or outside the surface.

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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TonyB <ben### [at] panamaphoenixnet> wrote:
: And why does this matter?

http://www.students.tut.fi/~warp/povVFAQ.html#blackspots

explains also this.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Nieminen Juha wrote:
> 
> TonyB <ben### [at] panamaphoenixnet> wrote:
> : And why does this matter?
> 
> http://www.students.tut.fi/~warp/povVFAQ.html#blackspots
> 
> explains also this.

 Strangely this is the first time I have heard of this particular problem
and was surprised that you have it included in the VFAQ. Good job Warp :)

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Ken <tyl### [at] pacbellnet> wrote:
:  Strangely this is the first time I have heard of this particular problem
: and was surprised that you have it included in the VFAQ. Good job Warp :)

  We see from this that even advanced users should read the VFAQ... ;)

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Nieminen Juha wrote:
> 
> Ken <tyl### [at] pacbellnet> wrote:
> :  Strangely this is the first time I have heard of this particular problem
> : and was surprised that you have it included in the VFAQ. Good job Warp :)
> 
>   We see from this that even advanced users should read the VFAQ... ;)

Well I figured out for myself what was causing the problem and even replied
as such hours before you did. I just didn't know that little one liner had
been included in the VFAQ. No need to memorize it when you are an advanced
user :)

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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