Celestia Forums

Apparently, Celestia can use a cloud shadows map. I didn't knew that. Look here :

Without shadows :
http://216.231.48.101/~impulse/Cloud-Sh ... adows1.jpg

With shadows :
http://216.231.48.101/~impulse/Cloud-Sh ... adows1.jpg

I already have a cloud-shadows map from here :

http://216.231.48.101/~impulse/

But how can I use it ? What is the command in Celestia to use cloud shadows ?

Define the cloud shadow image as a "limit of knowledge" texture.
It must include an alpha channel which is transparent where there are no shadows.

"Limit of Knowledge" textures do not move, so this trick only works if your clouds also do not move: CloudSpeed 0

Then, there's a big limitation here, isn't ?

I mean, can I use this cloudShadow-map associated to a cloud texture, without affecting the earth texture itself ?

If I drop the clouds to see the earth texture, I'll have this cloudShadows drawn on the earth texture.

If I define an alternate surface to use the cloudShadow texture, I wont be able to use the shadows with another alternate earth texture, right ?

I guess I'm forced to double all my earth alternate surfaces to see them all with clouds and cloudShadows ?

Is there a way out of this serious limitation ?

Sorry, I used the wrong term: the SSC command is "OverlayTexture", which happens to be what also is used for "limit of knowledge" surfaces. Here's a code fragment for the Earth:

You are exactly right.

This is just a hack until real cloud shadows are available.

Ok, thanks a lot Selden.

I'll make only one double alternate surface with clouds shadow for my finest earth texture (16k).

it would be nice if we could (load)enable/disable the overlay texture from the celestia menu or keyboard shortcuts, That way we could add the line: "OverlayTexture "Earth_Cloud_Shadows_8k.dds" to the reguallar earth in solarsys.ssc and enable/disable the shadows when needed on-fly. insted of adding a alternative texture,

The only way right now to enable/diable the overlay texture is by loading/unloading the alternative earth texture,
but when you add the line "OverlayTexture" to the reguallar solarsys.ssc /earth then there is no way to
unload it, even with render-clouds "off".

In my original implemantation this was posible and I can do it. I gave the instruction as to how to set this feature up. I suggest going back and finding the thread about "Celetia Now Has Cloud Shadows". I believe the info is in there. If not I can post my .ssc lines so you can enable being able to toggle between having shadows on or off.

Don. Edwards

Hi Don, I could not find any line but the "alt-texture" line when looking at the "Celetia Now Has Cloud Shadows" thread. I will search more for just "cloud shadows" to see what I can find on this forum, tnx.

http://www.celestiaproject.net/forum/viewtopic ... c&start=15

""""""""""""""""""""""""""""""""
AltSurface "Cloud Shadows" "Sol/Earth"
{
Texture "Earth.*"
OverlayTexture "8k-CloudShadowMap.dds"
NightTexture "NightLight.*"
SpecularTexture "earth-spec.*"
Color [ 0.85 0.85 1.0 ]
SpecularColor [ 0.5 0.5 0.55 ]
SpecularPower 25.0
HazeColor [ 1 1 1 ]
HazeDensity 0.36
Radius 6378.140 # equatorial
# Oblateness 0.0034

BumpMap "Earth-Bump.*"
# BumpHeight 4.5
}
"""""""""""""""""""""""""""""""

Here is what my Earth section of my last updated entry in my solarsys.ssc looks like.
"Earth" "Sol"
{
Texture "Earth12-12-03.dds"
# Texture "earth8k.dds"
NightTexture "land_ocean_ice_lights_aurora_4k.dds"

SpecularTexture "e43_mask_type2_8k.dds"
Color [ 0.85 0.85 1.0 ]
SpecularColor [ 0.5 0.5 0.55 ]
SpecularPower 25.0
HazeColor [ 1 1 1 ]
#HazeColor [ 0.40 0.6 1.0 ]
HazeDensity 0.36
Radius 6378.140 # equatorial
# Oblateness 0.0034

NormalMap "m43_bump_8bit_8k.dds"
# BumpMap "earthbump.*"
# BumpHeight 4.5

Atmosphere {
Height 85
Lower [ 0.43 0.52 0.65 ]
Upper [ 0.26 0.47 0.84 ]
Sky [ 0.40 0.6 1.0 ]
Sunset [ 1.0 0.6 0.2 ]
# Sunset [ 0.3 1.0 0.5 ]
CloudHeight 13
CloudSpeed 00
CloudMap "clouds-121303-8k.dds"
}

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
}

AltSurface "Cloud Shadows" "Sol/Earth"
{
Texture "Earth12-12-03.dds"
OverlayTexture "4k-CloudShadowMap.dds"
NightTexture "land_ocean_ice_lights_aurora_4k.dds"
SpecularTexture "e43_mask_type2_8k.dds"
Color [ 0.85 0.85 1.0 ]
SpecularColor [ 0.5 0.5 0.55 ]
SpecularPower 25.0
HazeColor [ 1 1 1 ]
HazeDensity 0.36
Radius 6378.140 # equatorial
# Oblateness 0.0034

BumpMap "Earth-8K-Bump-X13.dds"
# BumpHeight 4.5
}

You can edit in the name of your textures and than paste it and replace the stock Earth info or you can just use it as an example of how to it. By using it the way you see it you will be able to togle the cloud layer on and off. When you right click on the Earth the alternate texture menu should have an entry for "Cloud Shadows". By clicking this you can turn the shadows on or off.
Hope this answers any questions. I was sure I posted somewhere as to how to do this. Also check the read-me file that came with the cloud shadow texture. Maybe that is were I put it.

Don. Edwards

Thanks Don, It now works great, I load the default earth with the "overlay shadows ON" and using the alternative texture for turning them OFF,
I was against Alternative Textures because I believed that Celestia maybe would Load all the earth textures/normal/night maps again even if they would be the same as the stock textures, but I found out that I was wrong and Celestia does not load All the textures again if they are the same and only loads the new added textures. so no extra loading/waiting time ,

The Cloud shadows really look great,




#Cloud Shadows ON
"Earth" "Sol"
{
Texture "Earth_Virtual_32k.ctx"

OverlayTexture "Earth_Cloud_Shadows_8k.dds"

NightTexture "Earth_Night_8k.dds"

SpecularTexture "Earth_Spec_32k.ctx"
Color [ 0.4 0.4 1 ]
SpecularColor [ 0.5 0.5 0.55 ]
SpecularPower 25.0
HazeColor [ 0.43 0.52 0.65 ]
HazeDensity 0.65
Radius 6378
# Oblateness 0.003

NormalMap "Earth_Normal_8k.dds"
# BumpMap ""
# BumpHeight 0.0

Atmosphere {
Height 300
Upper [ 0.4 0.4 1 ]
Sky [ 0.30 0.48 0.82 ]
Sunset [ 1.0 0.6 0.2 ]
Lower [ 0.30 0.52 0.65 ]
CloudHeight 13
CloudSpeed 0
CloudMap "Earth_Clouds_8k.dds"
}

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
}


#Cloud Shadows OFF
AltSurface "Cloud Shadows OFF" "Sol/Earth"
{
Texture "Earth_Virtual_32k.ctx"
NightTexture "Earth_Night_8k.dds"
SpecularTexture "Earth_Spec_32k.ctx"
Color [ 0.4 0.4 1 ]
SpecularColor [ 0.5 0.5 0.55 ]
SpecularPower 25.0
HazeColor [ 0.43 0.52 0.65 ]
HazeDensity 0.65
Radius 6378.140 # equatorial

NormalMap "Earth_Normal_8k.dds"
}

Hi Don,

Are your 8k cloudmap and matching shadows still available somewhere? I could not find them any more...