The sky is one of the most integral components of an outdoor composition - it dictates the lighting and color palette, it casts the mood and drives the story, and frequently, it can consume a majority of the pixels on-screen. Yet, it's often one of the most overlooked, snubbed components of level creation. And for making it move? Most practices either look terrible, or require vast amounts of time and technology. Within this presentation, Keith will walk the audience through the artistic considerations of creating a compelling, dramatic sky to cast as a backdrop for their artwork. More importantly, he'll introduce the production challenges of skies within The Last of Us, and teach the audience how we were able to use vector fields, flow and some simple math to imply the motion of clouds receding into the horizon on a single matte painting, without losing our fast iteration.