My <<EXPORT lib/g10/forests/AG_trees_EU1.for forests/AG_trees_EU1.for>> instead of referring to the real path in the resources folder is now referring to a real path in a Custom Scenery file I made to show winter trees using a REGION_DREF , REGION_DEFINE and REGION_BITMAP to control the scenery appearance. The result is that the winter trees show up even in July. My other forests and draped polygons in the same scenery package are controlled correctly.