Celestia Forums

Posted: **16.10.2006, 11:18**

I am starting a little cloud experiment to see if I can render a more realistic simulation of clouds. Basicly I want to create a simple sphere mesh and use it a number of times with different radii each having a different coudmap. By changing the rotation period, I found I can get them to move relative to the earth's position. What I want to try next is have beginning and ending declarations to vary the opacity so they appear and disappear to simulate changing dew points and low pressure formation during the day.

rra wrote:

Cartrite , for the first part of your experiment,
did you only adapt the solarsys.ssc file or maybe more ?
If so, could you show me how your solarsys.ssc looks like
(I mean up to the first part, without the normap-map problems)

Code: Select all

"Earth1" "Sol"
{
   #Mesh "b.cmod"
   Mesh "b3.cmod" # smaller model
   #Texture "earth-clouds1.*"
   #Radius 6398.140  # works with no spec or norm
   Radius 6792.140
   #Oblateness 0.0054
   CustomOrbit "vsop87-earth"
   EllipticalOrbit {   
      Period            1.0000
      SemiMajorAxis     1.0000
      Eccentricity      0.0167
      Inclination       0.0001
      AscendingNode   348.739
      LongOfPericenter 102.947
           MeanLongitude   100.464
   }
   RotationPeriod   25.9344694 # 23.93419
   Obliquity        -26.45
   RotationOffset   280.5    # offset at default epoch J2000

   Albedo            0.3
}

"Earth2" "Sol"
{
   #Mesh "a.cmod"
   Mesh "a3.cmod" # smaller model
   #Texture "earth-clouds.*"
        NormalMap "clouds-norm.*"
   #Radius 6398.140  # works with no spec or norm
   Radius 6398.140
   #Oblateness 0.0054
   CustomOrbit "vsop87-earth"
   EllipticalOrbit {   
      Period            1.0000
      SemiMajorAxis     1.0000
      Eccentricity      0.0167
      Inclination       0.0001
      AscendingNode   348.739
      LongOfPericenter 102.947
           MeanLongitude   100.464
   }
   RotationPeriod   23.9344694 # 23.93419
   Obliquity        -23.45
   RotationOffset   280.5    # offset at default epoch J2000

   Albedo            0.3
}

"Earth3" "Sol"
{
   #Mesh "c.cmod"
   Mesh "c3.cmod" # smaller model
   #Texture "earth-clouds2.*"
   #Radius 6398.140  # works with no spec or norm
   Radius 6404.140
   #Oblateness 0.0054
   CustomOrbit "vsop87-earth"
   EllipticalOrbit {   
      Period            1.0000
      SemiMajorAxis     1.0000
      Eccentricity      0.0167
      Inclination       0.0001
      AscendingNode   348.739
      LongOfPericenter 102.947
           MeanLongitude   100.464
   }
   RotationPeriod   19.9344694 # 23.93419
   Obliquity        -21.45
   RotationOffset   280.5    # offset at default epoch J2000

   Albedo            0.3
}

I didn't need the models to have mutiple cloud layers. Just 2 earths with slightly smaller radii than the real one, But I think I need them to control opacity. That's how I want to try to get clouds to appear and disappear. Like fog banks burning off in the morning sun. This ssc file is loading 3 cloudmaps. It is in an addon folder.

cartrite

Posted: **20.10.2006, 05:43**

"Earth" "Sol"
{
Texture "earth.*"
NormalMap "earth-norm.*"
NightTexture "earthnight.*"

#SpecularTexture "earth-spec.*"
Color [ 0.85 0.85 1.0 ]
#OverlayTexture "8k-CloudShadowMap.dds"
#opacity 1
#SpecularColor [ 0.280 0.270 0.255 ] #was .0240 0.270 0.255
#SpecularColor [ 0.760 0.680 0.525 ]
#SpecularColor [ 0.80 0.70 0.55 ]
#SpecularColor [ 0.40 0.35 0.275 ]
SpecularColor [ 0.266 0.233 0.183 ] #last used
#SpecularColor [ 0.5 0.5 0.55 ]
SpecularPower 25.0
#HazeColor [ 1 1 1 ]
HazeColor [ 0.16 0.37 0.54 ]
HazeDensity 0.7
Radius 6378.140 # equatorial
Oblateness 0.0054

# BumpMap "earthbump.*"
# BumpHeight 4.5

Atmosphere {
Height 60
Lower [ 0.43 0.52 0.65 ]
Upper [ 0.16 0.37 0.74 ]
Sky [ 0.40 0.6 1.0 ]
Mie 0.0005
#MieAsymmetry 0.40
MieAsymmetry -0.15
#Rayleigh [ 0.001 0.0025 0.006 ]
Rayleigh [ 0.00025 0.0009 0.0015 ]
#Rayleigh [ 0.000485 0.00165 0.00285 ]
#Absorption [ 0.008 0.004 0.002 ] #dark blue
Absorption [ 0.00018 0.00005 0.0 ]
#Absorption [ 0.0 0.0 0.0 ]
MieScaleHeight 28
Sunset [ 1.0 0.6 0.2 ]
#Sunset [ 0.3 1.0 0.5 ]
CloudHeight 15
CloudSpeed 0
#CloudMap "4k_north_summer_clouds.png"
#CloudMap "clouds-121303-8k.dds"
#CloudMap "katrina-earth-clouds.*"
#CloudMap "earth-clouds.*"
CloudMap "earth-clouds.*"
CloudNormalMap "earth-clouds-norm.*"
#CloudMap "4kclouds-trans.*"
#CloudNormalMap "4kclouds-trans-norm.*"
}

CustomOrbit "vsop87-earth"
EllipticalOrbit {
Period 1.0000
SemiMajorAxis 1.0000
Eccentricity 0.0167
Inclination 0.0001
AscendingNode 348.739
LongOfPericenter 102.947
MeanLongitude 100.464
}

RotationPeriod 23.9344694 # 23.93419
Obliquity -23.45
RotationOffset 280.5 # offset at default epoch J2000

Albedo 0.30
}

"Earth2" "Sol"
{
Texture "invisible.*"
#NormalMap "earth-norm.*"
#NightTexture "earthnight.*"

#SpecularTexture "earth-spec.*"
#Color [ 0.85 0.85 1.0 ]
#OverlayTexture "8k-CloudShadowMap.dds"
#opacity 1
#SpecularColor [ 0.280 0.270 0.255 ] #was .0240 0.270 0.255
#SpecularColor [ 0.760 0.680 0.525 ]
#SpecularColor [ 0.80 0.70 0.55 ]
#SpecularColor [ 0.40 0.35 0.275 ]
#SpecularColor [ 0.266 0.233 0.183 ] #last used
#SpecularColor [ 0.5 0.5 0.55 ]
#SpecularPower 25.0
#HazeColor [ 1 1 1 ]
#HazeColor [ 0.16 0.37 0.54 ]
#HazeDensity 0.7
Radius 6370.140 # equatorial
Oblateness 0.0054

# BumpMap "earthbump.*"
# BumpHeight 4.5

Atmosphere {
Height 60
Lower [ 0.43 0.52 0.65 ]
Upper [ 0.16 0.37 0.74 ]
Sky [ 0.40 0.6 1.0 ]
Mie 0.0005
#MieAsymmetry 0.40
MieAsymmetry -0.15
#Rayleigh [ 0.001 0.0025 0.006 ]
Rayleigh [ 0.00025 0.0009 0.0015 ]
#Rayleigh [ 0.000485 0.00165 0.00285 ]
#Absorption [ 0.008 0.004 0.002 ] #dark blue
Absorption [ 0.00018 0.00005 0.0 ]
#Absorption [ 0.0 0.0 0.0 ]
#MieScaleHeight 28
Sunset [ 1.0 0.6 0.2 ]
#Sunset [ 0.3 1.0 0.5 ]
CloudHeight 12
CloudSpeed 0
#CloudMap "4k_north_summer_clouds.png"
#CloudMap "clouds-121303-8k.dds"
#CloudMap "katrina-earth-clouds.*"
#CloudMap "earth-clouds.*"
CloudMap "earth-clouds1.*"
#CloudNormalMap "earth-clouds-norm.*"
#CloudMap "4kclouds-trans.*"
#CloudNormalMap "4kclouds-trans-norm.*"
}

CustomOrbit "vsop87-earth"
EllipticalOrbit {
Period 1.0000
SemiMajorAxis 1.0000
Eccentricity 0.0167
Inclination 0.0001
AscendingNode 348.739
LongOfPericenter 102.947
MeanLongitude 100.464
}

RotationPeriod 27.9344694 # 23.93419
Obliquity -23.45
RotationOffset 280.5 # offset at default epoch J2000

Albedo 0.30
}

"Earth3" "Sol"
{
Texture "invisible.*"
#NormalMap "earth-norm.*"
#NightTexture "earthnight.*"

#SpecularTexture "earth-spec.*"
#Color [ 0.85 0.85 1.0 ]
#OverlayTexture "8k-CloudShadowMap.dds"
#opacity 1
#SpecularColor [ 0.280 0.270 0.255 ] #was .0240 0.270 0.255
#SpecularColor [ 0.760 0.680 0.525 ]
#SpecularColor [ 0.80 0.70 0.55 ]
#SpecularColor [ 0.40 0.35 0.275 ]
#SpecularColor [ 0.266 0.233 0.183 ] #last used
#SpecularColor [ 0.5 0.5 0.55 ]
#SpecularPower 35.0
#HazeColor [ 1 1 1 ]
#HazeColor [ 0.16 0.37 0.54 ]
#HazeDensity 0.7
Radius 6370.140 # equatorial
Oblateness 0.0054

# BumpMap "earthbump.*"
# BumpHeight 4.5

Atmosphere {
Height 60
Lower [ 0.43 0.52 0.65 ]
Upper [ 0.16 0.37 0.74 ]
Sky [ 0.40 0.6 1.0 ]
Mie 0.0005
#MieAsymmetry 0.40
MieAsymmetry -0.15
#Rayleigh [ 0.001 0.0025 0.006 ]
Rayleigh [ 0.00025 0.0009 0.0015 ]
#Rayleigh [ 0.000485 0.00165 0.00285 ]
#Absorption [ 0.008 0.004 0.002 ] #dark blue
Absorption [ 0.00018 0.00005 0.0 ]
#Absorption [ 0.0 0.0 0.0 ]
#MieScaleHeight 28
Sunset [ 1.0 0.6 0.2 ]
#Sunset [ 0.3 1.0 0.5 ]
CloudHeight 30
CloudSpeed 0
#CloudMap "4k_north_summer_clouds.png"
#CloudMap "clouds-121303-8k.dds"
#CloudMap "katrina-earth-clouds.*"
#CloudMap "earth-clouds.*"
CloudMap "earth-clouds1.*"
#CloudNormalMap "earth-clouds-norm.*"
#CloudMap "4kclouds-trans.*"
#CloudNormalMap "4kclouds-trans-norm.*"
}

CustomOrbit "vsop87-earth"
EllipticalOrbit {
Period 1.0000
SemiMajorAxis 1.0000
Eccentricity 0.0167
Inclination 0.0001
AscendingNode 348.739
LongOfPericenter 102.947
MeanLongitude 100.464
}

RotationPeriod 20.9344694 # 23.93419
Obliquity -23.45
RotationOffset 280.5 # offset at default epoch J2000

Albedo 0.30
}

A pleasant surprise. I just noticed this by acident. By having so many cloud layers, it fixes the sky in OGL2.
Edit I just found that this newer version of cvs 10/19 is not running the extra cloudmap. Forgot to copy it over.
So this effect must be caused by having 3 different atmospheres.

cartrite

Posted: **20.10.2006, 06:14**

I think what is really happening here is one atmosphere is being rendered ith the new atmosphere code and the other 2 are using the old code beause I have #MieScaleHeight 28 .
So probally only 2 are needed.

Posted: **20.10.2006, 06:41**

This shot shows 2 atmospheres and both are rendering the old atmosphere code.

These shots show 1 atmosphere rendering the new ode and the other atmosphere rendering the old.
The first shot is the same as the one above.

cartrite

Posted: **20.10.2006, 15:04**

Interesting experiments . . . It suggests some modifications to the new atmosphere code that could make the zenith less dark (without having to actually use two atmosphere definitions.)

--Chris

Posted: **20.10.2006, 15:07**

Cool

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