How to make land map on gas planet? (Bespin, Mygeeto)

[Filo]

How to make map like the bespin, mygeeto, also kamino which doesn't actually have solid ground just platforms over the sky or water or something. I tried to edit original maps, but when I load PNG with height, the ground appears. How can I make it? I know its possible cause I've seen custom maps like these.
Please, help

[Sidious Invader]

In the texture menu you need to select a texture, then look for the "hole" Check box. This will make the texture invisible so you see the skydome above, and below the ground plain. Now keep in mind your units will travel on the groundplain regardless of the invisible texture, so you'll need to paint passability. Open up Bespin, and find the texture that has the "hole" function checked. Then select a texture that doesn't have the hole function selected. Now paint around one of the landing platforms, the ground plain will become visible, so you can see how they made thier platforms, and ramps.

[Filo]

Hey, it works
Thank you, you helped me a lot