I'm trying to make an underwater scene using a heightfield and photons.
There are bright white dots on the heightfield. I can't get rid of them.
I have tried with many combinations of gather and radius, but no avail.
  The funny thing is that if I replace the heightfield with a plane, there
are no white dots.
  What photon settings should I use?

  The scene follows:

#version Unofficial MegaPov 0.4;

#declare UsePlane=no;

global_settings
{ photons
  { //count 100000
    radius 2
    spacing .4
    jitter .4
    media 100
  }
}

camera { location -z*10 look_at 0 angle 35 }
light_source { <1000,3000,0> 1 }

fog
{ fog_type 2
  distance 30
  rgb <.4,.6,.8>
  fog_offset -4
  fog_alt 10
}

sky_sphere
{ pigment { gradient y color_map { [0 rgb <.7,.9,1>] [1 rgb z] } }
}

#if(!UsePlane)
height_field
{ pattern 200, 200
  { hf_gray_16
    granite color_map { [0 rgb 0][1 rgb 1] }
    scale .5
  }
  smooth
  pigment
  { granite color_map { [0 rgb <1,.7,.3>][1 rgb <.8,.5,.1>] }
    scale .5
  }
#else
plane { y,.5 pigment { rgb <1,.7,.3> }
#end
  translate <-.5,0,0>
  scale <100,3,100>
  translate <0,-4,-2>
}

box
{ <-30,5,-11><30,-4,200> hollow
  pigment { rgbf <.95, .96, 1, .95> }
  normal { bumps 1 scale 1.5 }
  finish { specular .5 reflection .2 }
  photons { target refraction on ignore_photons }
  interior
  { ior 1.33
  }
}


-- 
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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Warp <war### [at] tagpovrayorg> wrote...
>   I'm trying to make an underwater scene using a heightfield and photons.
> There are bright white dots on the heightfield. I can't get rid of them.
> I have tried with many combinations of gather and radius, but no avail.
>   The funny thing is that if I replace the heightfield with a plane, there
> are no white dots.
>   What photon settings should I use?

If you comment out "smooth" in your height field, the white dots go away.  I
don't yet know exactly what causes them.

-Nathan

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Nathan Kopp wrote:
> 

> If you comment out "smooth" in your height field, the white dots go away.  I
> don't yet know exactly what causes them.

If you don't comment out "smooth" and increase scale:

height_field
{ pattern 300, 300
  { hf_gray_16
    granite color_map { [0 rgb 0][1 rgb 1] }
    scale .8 //<--- changed from 0.5
  }
  smooth
  pigment
  { granite color_map { [0 rgb <1,.7,.3>][1 rgb <.8,.5,.1>] }
    scale .5
  }

then there are a lot less of these white dots. 

Antti

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