During my internship as a Marketing Artist at Ubisoft Montpellier I was in charge of creating marketing screenshots for Assassin's Creed Unity: Dead Kings. It is basically in-game photography, everything is rendered in engine and using the assets from the game, for this I was required to find the composition and areas, pose the characters and only adjust/place objects and lighting to improve the compositions.
None of the 3D work is mine that was done by the really talented team over at Ubisoft Montepellier.