As Dan said about extinction in scattering statement a lower value than
1 typically increases brightness of the media interacted by lights,
however as Ken suggested about using more intense lights (I do use 1.5
total light color though) that may not be the way to go, especially rgb
15! Reason being, the rest of a scene needs to be considered; most of
all, textures.
Try increasing the scattering rgb instead.
Here's a complete pov script showing a spotlight illuminating the "air".
Please keep in mind this is all I've been able to come up with to check
atmosphere making so beware.

//BEGIN (check for line-wrapping)
light_source {
  0*x
  color rgb 1 //normal enough intensity for testing
  spotlight
  translate <-2, 0, 0>
  point_at <0, 0, 0>
  radius 15
  tightness 1 //default is 10
  falloff 30
  fade_distance 2 fade_power 1 //reduce reach
  media_interaction on
   media_attenuation off //with this off render speeds up considerably
}

camera { //an offset point of view
  location  <-3, 0,-9>
  direction 3*z
  look_at   <0, 0, 0>
}

//the "air" media
media {
 intervals 15 //if more than 2 lights, increase this integer
 samples 10,20
  confidence 0.96 //these two values don't have to be extremely high and
low
  variance 1/123
//ratio lower than 1 increases graininess at light/dark boundaries of
spotlights
   ratio 1
 //emission rgb .1 //not needed
 //absorption rgb .1 //not needed
 scattering {1,rgb .5 //increase rgb value for brighter lit "air",
darker unlit
  extinction .005} //zero if using sky_sphere
 density {rgb .5} //increase rgb value for brighter lit "air", darker
unlit
} //the scattering and density are of prime importance, density lesser
of two

//control object (should show up even if air does not)
box {-.5,.5 pigment {rgb 1} finish {ambient .1} rotate <30,30,30>
translate 1*x hollow}

//non-interacting light
light_source {<-2.5,-5,-10> color rgb .5 media_interaction off
media_attenuation off}

//comment out to see with sky_sphere instead
sphere {0,15 pigment {rgb<.3,.6,.9>} hollow}

sky_sphere { // daytime
  pigment
  {
    gradient y
    color_map { [0.0 color rgb<0.8,0.9,1.0>] [1.0 color
rgb<0.6,0.7,0.9>] }
  }
}
//END

Darcy Johnston wrote:
> 
> Can anyone possibly offer any help here? I've been trying to setup some
> atmosphere using media, hoping to have spotlighs running through it. I've
> followed the examples files that came with the distribution, but I can't get
> my light beams to show up in the media?
> 
> My media statement is:
> media {
>   intervals 40
>   scattering { 1, rgb 0.02}
>   samples 1, 10
>   confidence 0.9999
>   variance 1/1000
>   ratio 0.9
> }
> 
> And my lights are just spotlights with media_attenuation on. I've placed
> regular cones to verify that the beams should be within my field of view,
> but even though the cones show up, the beams never do (and yes, I have
> removed the cones <g>).
> 
> Any help would be appreciated,
> Darcy
> djo### [at] inamecomNOSPAM
> http://www.geocities.com/SiliconValley/Sector/4317

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/POVring.htm
=Bob

Post a reply to this message

Attachments:
Download 'us-ascii' (1 KB)