Admittedly, this is a tech demo which was designed to pack in the maximum amount of variation into the shortest possible time frame. Game development typically reuses the same carefully-crafted assets (particle systems, models, textures, shaders, even level geometry) in as many places as possible.
Yes this was rendered with the engine, but having the same camera angles, people, etc. you can do lots of tricks that you can't when doing interactive stuff ... ahem GAMES:
- You can cull your geometry offline (you know where you camera goes in and out)
- You can prefetch certain calculations that are to come soon (you know what's gonna happen)
- For sure you can implement correct motion blur filter as you know where you are moving
- Probably no physics - they might aswel prerecord them.
- In fact you can capture where each vertex, color, texture channel moves, and just replay it.
- And probably many more.
I'm not saying it's not cool, and I love good cutscenes in games (Metal Gear Solid), but people seem to confuse that
CUTSCENE RENDERED is the same as GAME RENDERED. No it's not.
So using the new engine, the world-leading experts on Unreal Engine NG - Epic - had to spend 1 person-year per minute of video.
Like Hollywood, this can only make hit-driven game design more common on consoles and PCs.