I've been interested in PBR (Physically Based Rendering) for a while. First, because it's becoming more and more popular (especially in videogame engines) and second, because there are tools nowadays (Quixel or Substance Painter) that allow for quick and easy PBR texture maps generation.
I've also done a lot of experimentation to get PBR materials to work on Cycles (you can get some insight in my investigations inside Luke's Escape High School), and that's why I'm blasted to see huge developments going on in a PBR Viewport project for Blender by Clément Focault.
Impressive, no? One of the big feats of PBR shading is that it's capable of computing microsurface roughness in real time, adding a realism previously impossible because of hardware and software limitations. Clément showed us a comparison between the same material rendered with Cycles and with PBR in real time: the result is truly amazing.
I hope we see this integrated into Blender soon!!