How to handle Landscape Materials in World Composition?

Hello,

I have planned quite a big world which will be devided into a few Levels with World composition. My plan was to have a Landscape Material for each of these Landscapes. This doesn’t seem to quite work however.

First of all, when I have multiple Materials assigned to the different Landscapes, all of them are shown in the “paint bar”, second of all when I use some of them on some Levels they are just black. The way I designed it seems to be very jercky, but I couldn’t find a good way to paint on a world composed of many landscapes. Does one of you know how this is done?

Thanks!