From 2008 to today, the Marvel Cinematic Universe has always employed a heavy use of CGI, as it's the only way to bring everything from Iron Man's armor to the landscape of Titan to life. We've all seen those behind-the-scenes images which reveal just how much of an MCU movie is created in post-production. It presents a unique challenge for the cast of these films as it means they have to rely on their imagination so much while shooting.