Model interaction issue

[Peacehagen]

So i have two doodads which acts very strange together. I am using an alpha tile and put a sky model down below ground level. Then i want to cut of the zone with a cloud model. However, even when the cloud model is higher than the sky model, the sky shows as its above the cloud (shown in image below). Is there an easy fix for this that can be done in the editor or its something with the models themselves?

Spoiler: Image

 

[tillinghast]

i think it's the models themselves, material filter mode or priority maybe