A crucial part of the Battle Royale formula is the storm – the wall of near-instant death that encroaches ever inward. It’s a necessary tool for ratcheting up the tension and action during the course of a match, even as permadeath ensures the number of players dramatically shrinks over time.
Nobody said the wall can’t be interesting, however. In Stormdivers, the nano-storm that repeatedly gobbles up a South Pacific-style idyll is a living system – a petri dish for tornadoes that rip through the map and lightning that stabs at its surface.
It’s been an opportunity for developer Housemarque to show its chops in visual effects, after decades spent building coin-op inspired arcade games.
The Finnish studio has a long history of shoot-’em-ups and twin stick arcade games on PlayStation platforms – you might have played Resogun, Super Stardust, or Matterfall. Stormdivers represents a conscious departure, and not only in genre. For Stormdivers, Housemarque has left behind trusted internal tech for the first time to create a new future in Unreal Engine 4.
Storm in a t-pose
“We were working with our own engine for quite a long time,” programmer Tuomas Hakkarainen tells us. “And while it provided us with a lot of flexibility for bringing in visuals, we always had a lack in the tooling department.”
While working in its own engine, Housemarque made all of the tools it wanted for each game from scratch. By switching to Unreal Engine 4, the studio can save valuable time by using the tools Epic has already built and countless other developers have already tested. The potential downside of licensing an engine would be a loss of flexibility – but Epic provides engine source code that enables Housemarque to create its own plug-ins and changes where needed.
“We have our own particle system,” game designer Henri Markus points out. “All the particle knowledge we learned from doing [PS4 twin stick shooter] Alienation is condensed in our own particle engine used in Unreal Engine 4. It might sound like a bold claim from a team of 16 people, but our game looks pretty fucking good. It’s a thing we do – visuals are as important to us as gameplay. Things need to look pretty, so we can blow them up pretty.”
The storm itself is wall of particle effects like no other, challenging the team to draw on over 20 years of experience. “To display the storm very viscerally, you have to create a huge amount of smoke, basically,” Hakkarainen explains. “The bigger the area of this dynamic smoke the player is seeing, the more it’s gonna tax their GPU. One of the things that we’ve had to do a lot is optimise those effects to be able to run on much, much lower end stuff.”
Markus is especially proud of the way the thunderstorm lights up. Hakkarainen, meanwhile, finds satisfaction in a bit of server trickery Housemarque pulled off that allows the storm to look so dramatic.
“On the server side we calculate the area of the storm and where it’s shrinking,” he says. “But we can’t do that in all the dimensions because it would kill the server immediately. That means we get to do a little bit of cheating where we do the easy math on the server side, and then on the client side we put this amazing visual effect on it so it seems much cooler.”
Tornadoes and tornadon’ts
Stormdivers’ extreme weather events aren’t all bad. The tornado makes a scene, for instance, but after its initial damage lifts you up in the air, where you might be able to surprise an enemy.
“They’re not entirely harmful to the players,” Markus says. “Their aim is to change the game field, switch the roles a little. Previously you might have had an advantage if you were higher up than the other guy, but when the eclipse comes, suddenly you’re in the dark and you have a flashlight on your gun and you’re more visible in that environment.”
The idea is that every event should emerge from the storm and make sense in that context. Moreover, Housemarque wants its weather to be organic – real systems at work in the world. “The tornado is randomly spawned, it goes in and out of the storm,” Markus explains. “There’s a force volume inside the tornado, in terms of code, and when that volume is close to an interactable object like a tree, it produces a reaction.”
The Stormdivers of the title are special operators who land on the game’s abandoned island to brave a permanent artificial storm built during a risky experiment. That fiction is not so different from the scenario players will find themselves in during open beta in December, testing out the wild systems Housemarque has created.
Stormdivers is slated for launch early next year. Unreal Engine 4 development is now free.
In this sponsored series, we’re looking at how game developers are taking advantage of Unreal Engine 4 to create a new generation of PC games. With thanks to Epic Games and Housemarque.