Lightmaps bakes with artefacts

Hello!

I have a big mesh - combination of multiple meshes. I made it for optimization. It looks like that: http://take.ms/wvpJ7

I'm trying to bake a lightmaps for it. I had choose "progressive (preview)" type of mapping, so I saw the process in my game view.
While baking is in progress in the very end of the process it looks perfect: http://take.ms/uFWfU
BUT after it finished (and compile or something) - it becoming terrifying: http://take.ms/mIUFW
Glitches everywhere!

I tryed to disable compression. I tryed to change scale and lightmap size. But it just not helping(

Can you plz give me some advice where could be a problem?

 

Did you try turning off filtering?

 

Thank for reply! Tryed it now, but the result is the same(

 

Ok, I have found the problem. In my quality settings the textures was set to "quarter res". Seems like it's applying to lightmaps too. With texture quality = full res baked lights have no any artefacts.
Now I wonder what should I do if I would like to cut texture quality for weak devices... How can I do it without light's artefacts?

 

A light map is a texture, so it gets treated like all other textures. I'm not sure if there's a way to make Unity treat it differently.