How to pack uv without breaking stacks of islands? I've done uv-mapping and tried to pack islands manually, but failed to fill the whole texture space.



But if I try packing this with blender auto-packing, it breakes stacks and I receive trashed uv-map, that I don't want.



So I wonder if it is possible do make blender distribute islands evenly, keeping stacks? Or I just need to try more and more manually? Seems like overkill though..

EDIT: It appears that 3d-coat is able to pack such stacked uvs without splitting the stacks. It actually has two variants of pack procedure: with and without 'shuffle' of the islands: without shuffle it will only move and scale the visible islands.

May be other apps can do it too, but blender can't (at least I don't see how).
UV mapping is not my strong point, but when I get undesirable results I alternate between Smart UV unwrapping and the ordinary version.  When that fails I do a UV unwrap--> reset first, then a "Follow active quads" I think it's called.  That seems to divide the image up into even surface areas.  Once done I go back and redo it with smart or ordinary unwrapping.

This might sound weird to some (or many) but this procedure has actually got me around a few UV problems.