I created a hex hill and 3 trees on it. So I have 4 objects,
1 x hexhill
3 x tree
The trees consist of 2 things, the leaves and the trunk.
I UV-unwrapped each of them into the same file.
BUT: When I export the UV map via “UV - Export UV layout” it always only exports ONE of the UVs, even though I click “Export UV Layout - All UVs” in the export options.
There has to be an option to just put all UVs into one file … I mean if I would have to export 7 times to get all those UVs into Photoshop, what about other people that have way more complex models? I must have not seen something … please tell me where to find the option
So far you have several different objects in your Scene. Did you know that any Object can have several UVs in Blender? This would be then related to Export UV Layout - All UVs for one Object. Since you probably have just one UV per object this is what you get.
In order to have one UV layout for all objects in your Scene you’d need to make one and easiest way to do this is to temporarily join all what you have and when finished with UV layout (yes, you could unwrap each object separately before) separate by Loose Parts e.g.
Almost the same does Texture Atlas addon.
I had all the obects unwrapped to the same layer, I saw them all (had forgotten the twigs earlier). When I join them, only 3 boxes remain (of the leaves). The hex hill, tree trunk/twigs etc. are all gone. It is still the unwrap-base image with the same name as before. You said I can unwrap before (and I understood that the unwrap stays usable). What do I have to do to keep the unwraps alive?
The UV maps are still there after the joining. Problem is: The UV maps have different names.
The UV map of the hex and the tree trunk is called “UVMap” and the UV map of the foliage is called “leafUV”. When joining meshes, UV maps with the same name will get merged, but maps with different names will stay separate as multiple UV maps on the same object. You can switch between the maps in the UV/Image editor:
I tried this now, and it looks good, but when I join all the objects the three squares (each one was standing for one of the leaves on a tree, I don’t really understand why it only unwraps 1 square for ALL the leaves, maybe the tree built with sapling extension creates the leaves as particles?) there is only 1 square left for all three trees and once I paint the unwrap file only 1 of the trees is green and the other 2 are grey … Do you understand why this is happening?
I also painted the upper right corner pink just to see if the trees would come out pink because maybe there were still the 2 original squares of tree 2 and tree 3, but they stayed gray.