Below is a matte painting before it was composited ( pic A ) . There were two distinct parts in that job : The first one was the creation of the background , a 4K " multitask " composition allowing for multiple framing values so it was reused in a few other shots . That really ensured the continuity . It was a full 2D piece , made of various pics and brush painting in Photoshop . The second process consisted in blending foreground CG ( pic B ) with the background to obtain a wide angle , homogeneous establishing shot . It s always a good thing work on advanced renders cause they contain strong references of textures , bouncing lights and other effects you would have to reproduce . But it can also be a time consuming job to find elements and details bringing a real enhancement . In this case , the pictures taken on the set during the shooting were very useful . Although they are not represented here , some more CG lights and telegraph poles were later added in the center alley to reinforce activity and "life" feeling . Comper also inserted smokes and glittering lights in the background for the same purpose .