Can anyone help me and unveil any way to bake through alpha in Blender? (exactly bake, not render via camera) At this moment I google almost everywhere - I can’t find any solution. If I’m just stupid and problem in me, i’m just not enough knowledged, it can be done in Blender - so ok. I will thank you for your reply.
But if I’m not - can anyone tell me where and who I have to ask or write letters to bring it into Blender?
Not the best move but I will refresh this topic time by time until get some reply.+
It’s simply not supported currently.
Such reply still better than nothing. Now I know that problem not in me. Thank you 
So it not supported yet - any plans, roadmaps or even work in progres in this direction?
Blender become more and more relevant software for game engines. Baking in generall and baking with alpha pass ( billboards, leaf clusters for foliages ) important thing for game engines workflows. When can we expect to see it in Blender? I even made topic on RCS and it even collect some votes so I’m not the only person in universe who need that.
