Custom Scenery Exchange / Super tall large scenery objects?

Hey. As you may well know, I make trees. And one of the trees I made, the dark pine one, is split into a bottom and a top section. I want to make more tall trees like that, but I don't want to split them up again... I heard it's possible to do them as single objects using the landmark editor, but I don't get how that works. Can someone shed some light on the matter?

Large scenery objects must be split up into different sprites per tile, as that's how the engine works. I don't know of any restriction on the height of a sprite (certainly there is no fundamental reason why there would be, and I didn't find a default object in which sprites are split vertically), but I haven't really experimented much with scenery, just looked at some existing objects. Someone else will probably be able to give you a better answer.

Open current objects in landmark editor and Extract .bmps with the, and edit them in paint. You'll have to edit the heights manually in a text editor. There's a guide that explains the nitty gritty out there.