I admit it took me some time to figure out what the hell PBR (Physically-Based Rendering) textures are.
When working in Blender, it takes quite a lot of manipulations to set up the nodes for albedo, normal, specular, ambiant occlusion, metallic and whatnot maps and it wasn’t obvious to understand that all of that is in fact completely useless since modern game engines can do all the job!

So, how does it work?
Let’s say I need to build some walls. I’ll start from photographs I took in one of the many medieval castles around my home place.

Then, in Photoshop, I’ll make the picture seamless, which means I can replicate any number of those images next to each other without seeing any seam between them.

Then comes into play Materialize, a – free! – software to make PBR textures. All I have to do is supply the seamless picture and from there let the software create all the maps I need according to the – numerous – options.
And here you go!

The PBR texture looks like a 3D thing while in fact it’s only a set of 2D images that the game engine uses to give the illusion of it being in 3D. That’s quite some maps, usually 5, and they are pretty heavy, reason why modern games take gigabytes on disk, but the engine can then give the illusion it’s displaying a very complex 3D object while in fact it’s only a few polygons.

For example, if I wanted to create a well, the above PBR texture would perfectly fit on a 32 polygons cylinder model and look like a multi thousands one.

It’s magic!