https://blendermarket.com/products/simplebake---simple-pbr-and-other-baking-in-blender-2

SimpleBake is the definitive baking solution for Blender. In short, it allows you to simply bake PBR and other textures.  Blender provides a very powerful way to create complex PBR materials by using nodes. However, what should be a simple process of baking and exporting these materials for use with other software or systems (Substance Painter, Second Life, Sketchfab, Unity etc.) is surprisingly difficult.