Maybe I put question in stupid way. I'll explain what I do not understand.
Entity has Skin1 or Skin2, and I can define bmap inside shader to do something with those Skins.
But what about panel? It is not entity and not sprite. But it has BMAP. So, how should I represent this BMAP in shader? Attach material to panel? Will this BMAP of panel become Skin1 or something?