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Night Side Texture and MIE?

Posted: 17.11.2007, 03:18
by BobHegwood
Just noticed that - along with all the changes to atmospheric
rendering - including but not limited to the MIE stuff - my favorite
nightside textures are now covered up by clouds. How this can be?
Are not the atmospheric effects more than 7 miles up in the atmosphere? I realize that the ground lights are covered by clouds
too, but didn't the aurora always display above the clouds?

CloudHeight is set to 7 miles. Never had any problem seeing the
Aurora til now.

Thanks, Brain-Dead

Posted: 17.11.2007, 11:56
by selden
Bob,

If the aurora you're using is defined as part of a NightTexture, then it's a ground effect. If you want your aurora to be high in the atmosphere, then you have to use a different method to simulate it.

One way to do this in Celestia is to define a dummy planet with glowing clouds as the aurora. (Real aurora are 3D, though, extending from about 80km to about 300km above the surface. That would require a rather more elaborate Addon.)

Here's an SSC which defines glowing clouds at an altitude of about 122km above the Earth. I'll leave it to you to create an appropriate cloud texture PNG image file and change the CloudMap filename. Your current auroral NightTexture image file could be used after you've erased all of its city lights.

Code: Select all

"EarthAurora" "Sol"
{
   Radius 6000
   Emissive true
   Atmosphere {
      CloudHeight 500
      CloudSpeed 0
      CloudMap "earth-clouds.*"
   }

   CustomOrbit "vsop87-earth"
   UniformRotation
   {
   Period              23.934469
   Inclination        -23.4392911
   MeridianAngle      280.5    # offset at default epoch J2000
   }
}

Posted: 17.11.2007, 15:05
by BobHegwood
Thanks AGAIN Selden...

Is there anything you DON'T know? :wink:

I just never had any problem viewing the auroras before, so I thought
that something had changed. Guess not.

Take care, Bob

Posted: 17.11.2007, 16:06
by selden
Bob,

There are lots of things I don't know!

However, I've beat my head against quite a few of Celestia's quirks, so I've had to figure out how to work around many of them.