I suggest you post the relevant parts of your source code: camera, light(s),
and all the media (and their container objects) that are having problems.

 - Slime
[ http://www.slimeland.com/ ]

Post a reply to this message

Sure here you:

media {
//    method 3
    scattering { 1, color rgb .02 }
//    intervals 1
    samples 5
    method 1
}

camera {
    location <-4, 3, -5>
    look_at .5
}

And here are the lights:
#declare spot_space=3.1;
#declare max_run=125;

#declare l_rad = 8;
#declare l_x = .25;
#declare l_z = -6;

#while (l_z < max_run)
    light_source {
        <l_x, 5, l_z>
        rgb <1,1,1>
        spotlight
        point_at <l_x, 0, l_z>
        radius l_rad
        falloff l_rad*2
        tightness 25
        media_attenuation on
    }
    #declare l_z = l_z + spot_space;
#end


This is projected to a BOX..
The spots all work fine, just the MEdia I'm having problems with.
"Slime" <slm### [at] slimelandcom> wrote in message
news:3ce5b3bb$1@news.povray.org...
> I suggest you post the relevant parts of your source code: camera,
light(s),
> and all the media (and their container objects) that are having problems.
>
>  - Slime
> [ http://www.slimeland.com/ ]
>
>

Post a reply to this message

Hi Norman--- er, Dave.

I don't see anything wrong here, using 3.5.beta.RC4.

Media method 3 is smooth with just your original scene script. Only thing
is, I needed to multiply your camera location by 3 in order to see a light
"cone" because of how close it is.

bob h

Post a reply to this message

I traced your scene and played a little with it.

One thing I noticed is that you have to take
into account that scattering media also darkens
the image as too much dust may "eat" the light.

Another one: Looks at beta-test, there's
a post on the 6. May from with title
"Media broken?", in which I ran into
that same problem.

I am not really sure, what the nature of this
effect is. Its all about sampling, intervals,
scatterings affection on the colors ect, so
it might just be look if you hit the correct
combination.

Peter Popov told me there to look at "ratio",
which places more samples in lit areas than
in unlit ones. Altogether I think this subject
could be made more clear by someone
who actually wrote the code and has some
specific insight. I didn't fully understand
why spotlights are not infinite and may be
traced in infinite media better than pointlights
in infinite media etc.



"Dave Bates [{Norman}]" wrote:

> Sure here you:
>
> media {
> //    method 3
>     scattering { 1, color rgb .02 }
> //    intervals 1
>     samples 5
>     method 1
> }
>
> camera {
>     location <-4, 3, -5>
>     look_at .5
> }
>
> And here are the lights:
> #declare spot_space=3.1;
> #declare max_run=125;
>
> #declare l_rad = 8;
> #declare l_x = .25;
> #declare l_z = -6;
>
> #while (l_z < max_run)
>     light_source {
>         <l_x, 5, l_z>
>         rgb <1,1,1>
>         spotlight
>         point_at <l_x, 0, l_z>
>         radius l_rad
>         falloff l_rad*2
>         tightness 25
>         media_attenuation on
>     }
>     #declare l_z = l_z + spot_space;
> #end
>
> This is projected to a BOX..
> The spots all work fine, just the MEdia I'm having problems with.
> "Slime" <slm### [at] slimelandcom> wrote in message
> news:3ce5b3bb$1@news.povray.org...
> > I suggest you post the relevant parts of your source code: camera,
> light(s),
> > and all the media (and their container objects) that are having problems.
> >
> >  - Slime
> > [ http://www.slimeland.com/ ]
> >
> >

--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html
Email: Tim### [at] gmxde

Post a reply to this message

Bob,

    Okay here is my question.. I've played aroudn with this a bit.. I added
a "Container" box and see the Cone faintly.. but Is there a way to make it
more intense without raising the intesity of the light?


"bob h" <omn### [at] charternet> wrote in message
news:3ce5f0f8$1@news.povray.org...
> Hi Norman--- er, Dave.
>
> I don't see anything wrong here, using 3.5.beta.RC4.
>
> Media method 3 is smooth with just your original scene script. Only thing
> is, I needed to multiply your camera location by 3 in order to see a light
> "cone" because of how close it is.
>
> bob h
>
>
>

Post a reply to this message

>     Okay here is my question.. I've played aroudn with this a bit.. I
added
> a "Container" box and see the Cone faintly.. but Is there a way to make it
> more intense without raising the intesity of the light?

Scattering media is hard to manipulate well. You should either increase or
decrease the color of the scattering (which is currently .02 i believe).
Increasing it may help because there will be more media for the light to
reflect off of, so it will be brighter. But decreasing may help because
there will be less unlit media blocking the light that *is* reflecting.

If you are only interested in seeing the media where the fog is, you may
want to ditch the scattering media and replace it with emission media in a
cone shape that matches the spotlight.

 - Slime
[ http://www.slimeland.com/ ]

Post a reply to this message

"Dave Bates [{Norman}]" <dab### [at] msncom> wrote in message
news:3ce66b6f$1@news.povray.org...
>
>     Okay here is my question.. I've played aroudn with this a bit.. I
added
> a "Container" box and see the Cone faintly.. but Is there a way to make it
> more intense without raising the intesity of the light?

Ahh yes, the ever present question about media.

It's a game of adjustment for me. I nearly always put a density {rgb 1}
statement in so I can raise and lower both it and scattering until something
looks okay. However, what most often works is a lower 'extinction' value
than the default (goes into scattering) of one. That way the media brightens
without changing the other parts.
Having read Tim Nikias' reply from this morning, he's certainly right about
the scattering media darkening objects, like a fog does. It isn't always
easy to balance out, hence extinction to the rescue. That thing about
ratio... it's a bit of a refined way to tweak, and doesn't show much change.
See the following, using your scene again with box I added:

media {
    scattering { 1, color rgb .02
         extinction .3 // lower brightens
          }
density {rgb 3} // higher can brighten light
    method 3
    samples 3 // 3 or more to adaptive sample (method 3)
    ratio .9 // default
}

camera {
    location <-4, 3, -5>*3
    look_at .5
}

#declare spot_space=3.1;
#declare max_run=125;

#declare l_rad = 8;
#declare l_x = .25;
#declare l_z = -6;

#while (l_z < max_run)
    light_source {
        <l_x, 5, l_z>
        rgb <1,1,1>
        spotlight
        point_at <l_x, 0, l_z>
        radius l_rad
        falloff l_rad*2
        tightness 25
        media_attenuation on
    }
    #declare l_z = l_z + spot_space;
#end

box {-1,1 scale <30,15,60>
        pigment {rgb <1,0,0>}
        finish {ambient .6 diffuse .6}
        hollow
}

Post a reply to this message

Bob.. That was, great.. the density was EXACTLY what I was looking for...

I appreciate all the help guys..
:)
D

"bob h" <omn### [at] charternet> wrote in message
news:3ce6778a@news.povray.org...
> "Dave Bates [{Norman}]" <dab### [at] msncom> wrote in message
> news:3ce66b6f$1@news.povray.org...
> >
> >     Okay here is my question.. I've played aroudn with this a bit.. I
> added
> > a "Container" box and see the Cone faintly.. but Is there a way to make
it
> > more intense without raising the intesity of the light?
>
> Ahh yes, the ever present question about media.
>
> It's a game of adjustment for me. I nearly always put a density {rgb 1}
> statement in so I can raise and lower both it and scattering until
something
> looks okay. However, what most often works is a lower 'extinction' value
> than the default (goes into scattering) of one. That way the media
brightens
> without changing the other parts.
> Having read Tim Nikias' reply from this morning, he's certainly right
about
> the scattering media darkening objects, like a fog does. It isn't always
> easy to balance out, hence extinction to the rescue. That thing about
> ratio... it's a bit of a refined way to tweak, and doesn't show much
change.
> See the following, using your scene again with box I added:
>
> media {
>     scattering { 1, color rgb .02
>          extinction .3 // lower brightens
>           }
> density {rgb 3} // higher can brighten light
>     method 3
>     samples 3 // 3 or more to adaptive sample (method 3)
>     ratio .9 // default
> }
>
> camera {
>     location <-4, 3, -5>*3
>     look_at .5
> }
>
> #declare spot_space=3.1;
> #declare max_run=125;
>
> #declare l_rad = 8;
> #declare l_x = .25;
> #declare l_z = -6;
>
> #while (l_z < max_run)
>     light_source {
>         <l_x, 5, l_z>
>         rgb <1,1,1>
>         spotlight
>         point_at <l_x, 0, l_z>
>         radius l_rad
>         falloff l_rad*2
>         tightness 25
>         media_attenuation on
>     }
>     #declare l_z = l_z + spot_space;
> #end
>
> box {-1,1 scale <30,15,60>
>         pigment {rgb <1,0,0>}
>         finish {ambient .6 diffuse .6}
>         hollow
> }
>
>
>

Post a reply to this message

"Dave Bates [{Norman}]" <dab### [at] msncom> wrote in message
news:3ce69f14@news.povray.org...
> Bob.. That was, great.. the density was EXACTLY what I was looking for...

Good thing, it's not always easy to get those things set up the way you'd
like.

bob h

Post a reply to this message

Well thatnks for all the help guys.. I got my first real Povray picture
done..

I'm not sure I want to post it.. it's not quite the caliber I see from alot
of the pictures in this NG.. but I might..

Thanks for all the help..
Dave

"Dave Bates" <dab### [at] msncom> wrote in message
news:3ce57c36@news.povray.org...
> Hello All,
>
>   Me again of course..
>
>   I'm doign some testing with Media interaction.. so I made a line of
> Spotlights, using a while statment.
>   Inside the light_source  I have media_attenuation turned on
>   Outside the block, I have atmospheric media create (I think).
>     media {
>         method 3
>         scattering { 1, color rgb .02 }
>     }
>
>     When I render the scene, the only change I see is that it renders
> slower.. I don't see what I expected, which would be a cone of light from
> the spotlight..
>
> Anyone got any suggestions??
>
> Thanks
> Dave
>
>
>

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