Celestia Forums

Hello,

I'm in the process of trying out a dds cloud file, but only get a 'white globe'. My other cloud files work fine (although they are not dds), and my dds map files (inlcuding the recent 16k dds earth file) work fine. I'm sure it's something obvious. I checked and rechecked my file names etc. Any help much appreciated.

Paul
_______________
Texture "Realistic-Earth16k.dds"
# Texture "earth.*"
# Texture "earth8k.dds"
NightTexture "earthnight.jpg"

# SpecularTexture "earthspec2k.jpg"
SpecularTexture "8kEarthSpecular.dds"
Color [ 0.85 0.85 1.0 ]
SpecularColor [ 0.5 0.5 0.55 ]
SpecularPower 25.0
HazeColor [ 1 1 1 ]
HazeDensity 0.3
Radius 6378
# Oblateness 0.003

NormalMap "earthbump4k.jpg"
# BumpMap "earthbump.*"
# BumpHeight 4.5

Atmosphere {
Height 60
Lower [ 0.30 0.52 0.65 ]
Upper [ 0.26 0.47 0.84 ]
Sky [ 0.30 0.48 0.82 ]
Sunset [ 1.0 0.6 0.2 ]
# Sunset [ 0.3 1.0 0.5 ]
CloudHeight 7
CloudSpeed 65
CloudMap "earth-clouds.dds"

Clound images often consist of a main texture that's all white plus a grey-scale alpha channel to define transparency and thus the cloud shapes. It sounds like your alpha channel got lost.

Of the image formats that Celestia supports, only png and dds/dxt3 images can include alpha channels: jpeg cannot. dxt1 can include a 1bit (black or white) alpha channel. Probably the components of a dds/dxt5 texture file can include alpha channels, too, but I don't know enough about them.

Does this help?

Thanks for your reply Selden. I simply downloaded the earth central 16k earth (which is brilliant by the way) and the northern summer - southern winter cloud map also provided on the site. It is this cloud map that I can't seem to get to work. Is there another file required for this cloud map to work that you (or anyone else) just happens to know about ?

selden wrote:Clound images often consist of a main texture that's all white plus a grey-scale alpha channel to define transparency and thus the cloud shapes. It sounds like your alpha channel got lost.

Of the image formats that Celestia supports, only png and dds/dxt3 images can include alpha channels: jpeg cannot. dxt1 can include a 1bit (black or white) alpha channel. Probably the components of a dds/dxt5 texture file can include alpha channels, too, but I don't know enough about them.

Does this help?

Sorry: I dunno. I haven't downloaded it. Hopefully Don Edwards can comment.