Man, I am having a devil of a time getting fog to work in this scene using
the clouds I stole from Jaime Piqueres.

I thought I had it figured out: the traditional fog and hollow-objects
problem, but nope.

Looking around, I don't see many people posting scene files to these groups,
so I'll post it to the text.scene-files.  Any help would definitely be
appreciated.

-s

Post a reply to this message

Um, what's wrong with it?  The lighter speckles scattered in places amongst
the fog on the sea?
Btw, there's a missing { in the "this is the sky" plane.
Using:

sphere  { <0, -100000, 0> 100000 hollow}

for the sea removes those artifacts, but also seems to remove the rest of
the characteristics.
So whatever made it look like a textured surface before wasn't a true
representation of the 'material' I guess and actually the fog instead.

Bob


"Skelter" <ske### [at] nospamfull-mooncom> wrote in message
news:3867d092@news.povray.org...
> Man, I am having a devil of a time getting fog to work in this scene using
> the clouds I stole from Jaime Piqueres.
>
> I thought I had it figured out: the traditional fog and hollow-objects
> problem, but nope.
>
> Looking around, I don't see many people posting scene files to these
groups,
> so I'll post it to the text.scene-files.  Any help would definitely be
> appreciated.
>
> -s
>
>
>
>

Post a reply to this message

Hey, Thanks for taking a look at it.

I thought I tested it before I zapped it off, but must have introduced a
typo while I was preparing a simple version to show the problem.

If you set the problem number 1, you get Jaime's *beautiful* non-media
clouds.  This turns off the fog.
If you set the problem number to 2, both the clouds and the fog are
activated.  Even if you move the camera out of the ground fog, the clouds
have turned to crap.  I tried making them hollow.  no luck.  They are now
dark, nasty and drama-less.  How does fog do this to the clouds?

If you set the problem number to 3, it turns off his clouds, but leaves the
fog on. This was mainly so I could assemble the rest of the scene and see
what I was doing.  But, as you've said, this is broken.

I'm not worried about the water texture yet; I'll address that later.


omniVERSE <inv### [at] aolcom> wrote in message
news:386869dc@news.povray.org...
> Um, what's wrong with it?  The lighter speckles scattered in places
amongst
> the fog on the sea?
> Btw, there's a missing { in the "this is the sky" plane.
> Using:
>
> sphere  { <0, -100000, 0> 100000 hollow}
>
> for the sea removes those artifacts, but also seems to remove the rest of
> the characteristics.
> So whatever made it look like a textured surface before wasn't a true
> representation of the 'material' I guess and actually the fog instead.
>
> Bob
>
>
> "Skelter" <ske### [at] nospamfull-mooncom> wrote in message
> news:3867d092@news.povray.org...
> > Man, I am having a devil of a time getting fog to work in this scene
using
> > the clouds I stole from Jaime Piqueres.
> >
> > I thought I had it figured out: the traditional fog and hollow-objects
> > problem, but nope.
> >
> > Looking around, I don't see many people posting scene files to these
> groups,
> > so I'll post it to the text.scene-files.  Any help would definitely be
> > appreciated.
> >
> > -s
> >
> >
> >
> >
>
>

Post a reply to this message

I looked at it again, I didn't even notice you set it up to check it the way
you had, was just rendering it and looking real quick.
Now I've re-rendered with the fog filter removed and it's fine.  So if you
can get by without it then it should be alright.
Here it is again with the change and the rest of it I was messing with, I
figure I better just let you see it yourself again since I was getting lost
trying to figure some other aspects of it (so many trial and errors, typical
of me to get lost).
There had been a discussion of a problem similar to this a while ago, I
didn't go look it up and I don't know if there were answers turned up at
all.  I had thought it might be 'sky_sphere' related.
Anyway, have a render at it like this and see if it's right now.

#include "colors.inc"
#include "textures.inc"

// Problem Number : set to 1, to show Jaime's Clouds, but turn off fog
//                  set to 2, to turn on fog, which screws up the clouds,
// even though they are hollow
#declare problem_num=2;

global_settings {
  adc_bailout 0.003922
  ambient_light <1.0,1.0,1.0>
  assumed_gamma 1.9
  hf_gray_16 off
  irid_wavelength <0.247059,0.176471,0.137255>
 // max_intersections 64
  max_trace_level 60 // 64 [real high numbers weren't helping]
  number_of_waves 10
/*
  radiosity {
    brightness       3.3
    count            100
    distance_maximum 0.0
    error_bound      0.4
    gray_threshold   0.5
    low_error_factor 0.8
    minimum_reuse    0.015
    nearest_count    6
    recursion_limit  4
  }
*/
}

#declare IslandWater = material {
  texture {
          pigment {
            rgbft <0.1, 0.3, .2, 0.99, 0.3>
          }
          normal {
            ripples 0.75
            frequency 10
            turbulence 0.1
          }
          finish {
            ambient 0.1
            diffuse 0.1
            reflection 0.3
            specular 0.2
            roughness 0.001
            // refraction 0.5
          }
  }
  interior { ior 1.33}
}

 #if (problem_num<=2)

#local __cloudysky_sky_color=SkyBlue;  // basic sky color
#local __cloudysky_clouds_height=5000; // first layer starts here
#local __cloudysky_clouds_height_floor=4000; // level of trimming of cloud
planes to allow fog
#local __cloudysky_plane_dist=40;      // distance between succesive planes
#local __cloudysky_textu_dist=40;      // distance between textures on
succesive planes
#local __cloudysky_num_planes=40;      // raise it for more "volume"
#local __cloudysky_cnt_planes=1;       // counter

  // plane {-y, __cloudysky_clouds_height_floor no_shadow finish {Luminous }
pigment { Clear } }
  // cylinder { <0, 3000, 20000> <0, 10000, 20000> 5000 no_shadow finish
{Luminous } pigment { Clear } hollow }
// place the planes
#while (__cloudysky_cnt_planes<=__cloudysky_num_planes)
// #render  concat(str(__cloudysky_cnt_planes, 5, 0),"\n")

 // basic pigment for the lower plane
 #local __cloudysky_p=__cloudysky_sky_color*.5+White*.5;

 // two derived pigments to mix on each plane, more "white" each pass
 #local
__cloudysky_p1=__cloudysky_p*(1-(__cloudysky_cnt_planes/__cloudysky_num_plan
es))+White*(__cloudysky_cnt_planes/__cloudysky_num_planes);
 #local
__cloudysky_p2=__cloudysky_p*.9*(1-(__cloudysky_cnt_planes/__cloudysky_num_p
lanes))+White*.9*(__cloudysky_cnt_planes/__cloudysky_num_planes);

         plane{  y,0
         // box { <-100000,0,-100000> <100000,1,100000>
                 texture{
                           pigment{
                                    granite           // try other
patterns...
                                    octaves 9
                                    lambda 3
                                    turbulence 4
                                    color_map{        // notice that each
plane has more transparency
                                     [0.0 Clear]
                                     [0.5 Clear]      // play with the
"cloud zone" entries
                                     [0.6 __cloudysky_p1 filter
0.7+0.1*(__cloudysky_cnt_planes/__cloudysky_num_planes)]
                                     [1.0 __cloudysky_p2 filter
0.7+0.1*(__cloudysky_cnt_planes/__cloudysky_num_planes)]
                                    }  // end color map
                            scale 1000000     // depends on the pattern
                           } // end pigment
                   finish{Luminous}   // prevent shadows
                   translate
(__cloudysky_clouds_height+__cloudysky_textu_dist*__cloudysky_cnt_planes)*y
                  } // end texture
          translate
(__cloudysky_clouds_height+__cloudysky_plane_dist*__cloudysky_cnt_planes)*y
           hollow
         } // end plane // box
         #local __cloudysky_cnt_planes=__cloudysky_cnt_planes+1;
#end

// "container" sky
sky_sphere{
// sphere {0,1 hollow // no sky_sphere anymore
 pigment{__cloudysky_sky_color}
 // scale 50000  // this size shows the bad interaction of planes and sphere
well
}

 #end // end Jaime's clouds

light_source{ <10000,10000,-10000> White  }
light_source{ < 4000, 4000, -4000> White } // below clouds

#if (problem_num>=2)

         fog {
            distance 150
            // color rgb<0.3, 0.3, 0.5, 1.0>
            color rgb<0.3, 0.3, 0.5>//, .1> // no filter or transmit !!
            // color rgbf<1, 0, 0, 1.0>
            // color rgb<1, 0, 0>
            fog_type 2
            fog_offset 10
            fog_alt 10
            turbulence 0.2
            turb_depth 0.3
         }

#end

// This is the sea
union {
        // box {  <-1000, 0, 10000> < 1000, -4, -10>    }
        sphere  { <0, -100000, 0> 100000 // hollow
        }
        sphere { <20, 3, 100> 10}
        material { IslandWater scale .1  translate < 0, 0, -10>}

}

// plane {y,0 pigment {rgb 0}} // checked ground/sea

// this is the sky

#if (problem_num=3)

        plane {

          <0, -1, 0>, -20000
          pigment { Bright_Blue_Sky scale 100000}
          finish { ambient 1 }
          no_shadow
        }
        sky_sphere {pigment {Bright_Blue_Sky } }
#end

#declare C_horizoncam = camera {
    location <0.3,100, -4.>
    direction z
    up y
    look_at <-0.1,4.3,500>
}

camera { C_horizoncam }

Post a reply to this message

I got to thinking about this problem with filtered (or transmited) fog and
it occured to me that what is happening is that it might get added as many
times as there are those planes of cloud texture.  So I checked and sure
enough it is, apparently.  If you have to use the filter in fog then
decrease the amount proportionally to the number of planes, in this case 40
of them so 1/40.
The drawback is that it will get done that way on other singular objects too
making for a less filtering on everything else (remember, filter includes
the color more the higher it is, unlike transmit).
This could be what was deduced earlier when it was a topic before.
Oh, and you can use a 'max_trace_level' of 1 more then the number of
'planes' too.
I needed to drop the sea 'interior' statement to get a tiny 80x60 res.
render done in 1 and a half minutes on this 500MHz PC.  So that's the next
thing to work on I guess, not sure why it was so much faster before when it
didn't work right  ;-)

Bob

Post a reply to this message

Hey, thank you very much.  That will help.

I've been thinking that maybe I should try media for the effect I want (the
haze over the sea).

Maybe I can turn off interior when I do the far off scene and turn it on
when I'm closer to the water and the objects that will be in it.

-s

omniVERSE <inv### [at] aolcom> wrote in message
news:3868f735@news.povray.org...
> I got to thinking about this problem with filtered (or transmited) fog and
> it occured to me that what is happening is that it might get added as many
> times as there are those planes of cloud texture.  So I checked and sure
> enough it is, apparently.  If you have to use the filter in fog then
> decrease the amount proportionally to the number of planes, in this case
40
> of them so 1/40.
> The drawback is that it will get done that way on other singular objects
too
> making for a less filtering on everything else (remember, filter includes
> the color more the higher it is, unlike transmit).
> This could be what was deduced earlier when it was a topic before.
> Oh, and you can use a 'max_trace_level' of 1 more then the number of
> 'planes' too.
> I needed to drop the sea 'interior' statement to get a tiny 80x60 res.
> render done in 1 and a half minutes on this 500MHz PC.  So that's the next
> thing to work on I guess, not sure why it was so much faster before when
it
> didn't work right  ;-)
>
> Bob
>
>
>

Post a reply to this message