Assassin's Creed IV: Black Flag is just over the horizon, and now Ubisoft is teasing us with a new trailer that explains the tech witchcraft behind its gorgeous seas and its 'breath-taking' weather effects.
They've gone all fancy with lighting, revealing the system has been built from the ground up. We even get a peek at the 'dynamic navmesh' for boarding ships - 'turning objects into 3D maps'.
There's plenty of foliage too with 'dynamic 3D plants', which are quite handy for skulking in as leaves rustle about to show us where we are.
Check out the 'Building a Next-Gen Open World' video below. Assassin's Creed IV: Black Flag releases on Xbox 360 and PS3 October 29th in the US, November 1st in EU. Xbox One, PS4 and PC later in 2013.