Daryl,
Unfortunately i do not have enough system memory(512) to work with 8x8k images in gimp for assembling the cloud textures. If memory serves me you have double that?
As for aliasing at the poles etc, the modis images don't have any data at the poles.
They have some similarities to the space-graphics texture(which i assume you're using) but mario seems to have added in alot of his own. Consequently a 32k texture could never be made based on mario's clouds as the 32k level would be very different to the rest.
My approach was to use the 8k blue marble for levels up to 8k and the modis data(which matches perfectly the BM clouds) for levels 16 and 32k.
If i could manage to make the tiles small enough the poles on the the higher levels could be left out, showing the lower resolution underneath. Since the clouds around the poles are not very interesting anyway, this seems like the best approach.
At the moment all my vt tiles are 4x4k which runs very slow and precludes the aforementioned pole tile exclusion as there would be no tiles left at the 16k level doing this.
Will you be releasing your 16k clouds for celestia? If you do i may not bother with mine. Your moon texture looks excellent as does io. I'm sure your clouds would be of a similiar standard.
Besides i've never found the leap from 16k to 32k to be all that much better-especially considering the increase in file size.
The eastern hemisphere from modis
Buzz,
Unfortunately the tiles are in dxt5 format(i deleated the png's when i decided to start over-because of too much bumpmapping etc). uncompressing them,trimming, rescaling and recompressing would probably just mangle them.