God of War's senior combat designer, Dean Rymer, gave an in-depth look at what it took to add Kratos' boat to the action game in a blog post. This different mode of transport, a first in the franchise's 13-year history, presented the developers with a variety of new problems to solve. It turns out that getting Kratos and his son Atreus cruising around the Lake of Nine hub area was a totally different process from finding new and creative ways for the former Greek God of War to dismember the monsters he meets on his quest. And it introduced some surprising variables.
The God of War reboot takes place years after Kratos destroyed the entire Greek pantheon and moves him to the world of Norse mythology. The hero and his son go on a mission to scatter his deceased wife's ashes from the top of a mountain. It all seems simple enough. But this simple task sets off a conflict that has the father and son taking on dragons, Valkyries, and the Norse god Baldur. Along with the changes in time period and setting, the new God of War took on a new camera and a more open-world feel instead of the previous entries' more level-based structure. And that's where the boat came in.
Writing on the Playstation Blog, Rymer shares that every element of creating the boat for God of War presented new challenges. The most immediate was figuring out how to animate Kratos as he paddled the craft across the watery hub world. They had to decide between a single paddle or two oars and manage how he'd look going in different directions. The quick solution was to build a cardboard mock-up in the motion-capture studio. This let designers look at all of their options and grab reference material before they made a single computer mock-up. The finished product has over 600 animations.
Once they knew how Kratos was going to move in the boat, designers had to figure out how the boat was going to move on the water. The team had to find a control system that both handled well and felt "right" to players. Rymer says that even deciding where the craft's momentum would originate was an iterative process:
"Originally the boat had its 'power' coming from the center. We effectively had an 'all-wheel drive' boat. We moved the 'power' to originate from the rear of the boat. Now we had a 'rear wheel drive' boat. Immediately, play testers not only had the perception that the turn rate was increased, but that the boat turned more predictably. They could now oversteer the boat to use its 'power' to position it where they expected it to go."
Even getting Kratos in and out of the boat required a multitude of decisions. The team wanted the transition between land and water to be seamless. But doing so required them to get around other mechanics. The main one was Atreus himself, who had context-sensitive A.I. In some cases, he'd follow behind Kratos. But other times, he was running ahead to point something out. Developers had to put special limits on Atreus' behavior to keep him out of the way.
Since Kratos can get onto the boat from any angle, the team didn't want Atreus to interfere. So Rymer says they established a "Son 'No Go' Zone" around every dock in the game. Atreus will never enter this area. He only seems to during the actual boarding animation, during which the code automatically figures out his approach angle based on the one the player took. The developers limit how much players can move the camera during these transitions to hide any animation weirdness that might arise.
Along with these more technical details, Rymer shared some other interesting tidbits about the boat in God of War. For example, the LED panel on the front of the PlayStation 4 controller turns a specific "aqua blue" color whenever Kratos is on the water. The paddling sequences also contain over 750 lines of dialogue, in which Kratos, Atreus, and Mimir swap stories. The oar itself is technically a weapon according to the game code, but sadly, Kratos never wields it as one. Maybe Sony is saving that for the inevitable God of War 5, whenever that comes out.
Source: Playstation Blog