How to add a scenery with a custom 3D object added?

No I was not able to add anything since 0.9 SDK but I don’t know if it’s my fault. There are so many new mods coming out every day, that I wonder how they do it. Or are those all Google earth caputre files, that do the relevant files for themselfs? I have to admit, I didn’t try very hard lately, I wait for the new Update of UK and hopefulle new SDK arriving at the same time and will try again then.