Elite: Dangerous fans: the recent trailer showing off an epic space battle was almost entirely rendered in the game engine. A new follow-up walks through the video and explains what was already in place, what was added specifically for the trailer, and how the video as a whole helped the design team.
While almost everything rendered in the trailer was generated in the game engine, the ships involved were all flying along pre-determined paths. This might not sound like a big deal until you realize that it allowed the art team to examine everything from multiple angles, making sure that things looked right from various paths without having to manually test each element. But don't take our word for it, just check out the companion trailer past the break and find out about it yourself.
[Thanks to Peteris for the tip!]