http://img.villagephotos.com/p/2005-10/ ... mpmap1.jpg
http://img.villagephotos.com/p/2005-10/ ... mpmap2.jpg
(These images may only be available for a limited time.)
The effect is much more apparent when the planet is in motion, and mostly as you approach the terminator (as is to be expected).
This technique involves 1) combining your cloud texture with your terrain texture in your paint program to create a new texture and 2) blending the cloud alpha mask with the terrain bumpmap so that the new bumpmap spans the combined heights of the two.
Since the cloud layer is now part of the terrain texture you'll want to turn off cloud rendering.
This makes a very nice "eye-candy" alternate surface if done properly but it's obviously not intended to replace high-resolution surface textures - although there is no reason why this can't be used for such, especially if psuedo cloud shadows are added. You just won't be able to go or see below the clouds.
![Razz :P](./images/smilies/icon_razz.gif)
Lone
P.S. Note the dust storm added off of the western Saharan coast and slash-and-burn smoke in central Africa and South America.
![Smile :)](./images/smilies/icon_smile.gif)