The work that went into the PS4 and Xbox One versions started at the end of the X360/PS3/PC versions. They were our foundation that we then built on top of. The amount of extra work - 3 studios and a full year of development - have pushed the boundaries beyond just TressFX and upgraded textures. We now have a new particle system, new lighting work and enhanced shadow-casters, tons of more visual storytelling elements (more debris, more details on walls, more density in the environment for vegetation), upgraded characters (Lara and main story NPCs), and we've also put all of the DLC materials into this version for PS4/Xbox One. We are very happy with the PC version we released and felt these new additions and changes were something custom just for next-gen consoles at the moment.