Photoscenry vs landclass scenery

I have propably silly question but I have no knowladge how to make scenery without photoscenery. When I finished my scenery I realized that distribution won`t be able because I live in europe ( no free source like USGS HR and sentinel sucks ). So I decided to erase photo.bgl. First I thought that agn files have own coordinates but it seems i was wrong couse all trees I ve planted disappeared. So annotator tool is useless without photoscenery or I have exclude default autogen.
And my another question is what programs allow me to create landclass and which one is best fot that purpose. If I create landclass polygon with forest then trees will appear on that poly? and no need to use annotator ? Is there any good tutorial how to create landclass using SBX or any other program ? I`m not familiar with terrain SDK so far. Sorry for my english by the way.
If you are creating landclass polygons in an airport area then you can create them in ADE. If you want to create them outside of an airport's radius then SBX would probably be a good tool. I don't know of a good tutorial sorry. I can tell you that autogen is driven by the landclass. If you define a landclass polygon as a forest then trees will be generated if the area is large enough.