Can I create pbr textures from blender and export it to Unreal or Unity? I would like to experiment with pbr on blender, using the pbr feature, I know people who export from substance painter  as albedo map, normal map, specular ,etc from substance to another engine such as unity or even unreal, I noticed that "whatever happens in cycles dies in cycles", but can my luck change ?
if I create Pbr maps and export in from blender cycles-Pbr to an engine?
pd : Cycles nodes does not exist in another engine! ,but pbr is an exception?
"PBR" is a buzzword that refers to some shader design conventions, such as respecting energy conservation, using fresnel reflections, and such. "PBR Textures" are merely textures intended for some shader that follows these conventions. As Cycles is a render engine itself and not a texture authoring tool, it won't be helpful in authoring textures. You can certainly paint textures using Blender's texture painting function that target a PBR shader, but as Blender doesn't have a PBR viewport shader you will won't have the instant viewport feedback of how your textures are looking. You have to export them out to your game engine, doing some "guess and check" with the values.