August 6, 2018
Holospark’s Earthfall brings innovation to the co-op shooter genre
Taking place in the not-too-distant future of 2031, players will be tasked with defending the lush environments of the Pacific Northwest against a violent alien invasion. Perhaps not as mindless as they seem at first, the alien invaders won’t go down too easy, but Earthfall will provide players with the firepower they need to mount their offense. Using the power of Unreal Engine 4’s development suite, Holospark has created enemies that smartly adapt to not only each player but the team dynamic as a whole, creating an experience like no other.
Now, coming out of Early Access and launching on PC, PlayStation 4 and Xbox One, Earthfall is poised to fill that void created by Left 4 Dead’s long absence from the gaming scene. We recently took some time to chat with Holospark CEO, Russell Williams, as the growing developer filled us in on their thoughts about working with Unreal Engine 4 and protecting the human race from alien devastation. Tell us a little bit about Holospark and how this highly experienced team came together?
Holospark is an independent video game developer in the Seattle area. We have two teams, one focusing on Earthfall, our four-player co-op shooter, and a smaller team working on VR projects.
Built from a core team of experienced developers that previously worked together we broke off looking to create something new and exciting on our own. After setting the studio up and working on some ideas, we decided we all loved co-op shooters and started building Earthfall in 2016.
Over the last two years, we have expanded to our current staff of 37. Many of these developers bring their extensive background working on dozens of projects including multiple award-winning titles. Holospark also has a great relationship with some of the local schools in the area allowing us to recruit an entirely new group of developers who are immensely talented and hungry to make an impact.

Aside from it being your own backyard, what is it about the Pacific Northwest that made it the ideal setting for your alien invasion story?
The Pacific Northwest is a gorgeous, moody environment perfect for spooky woods where aliens can come out at you from every turn. It feels both open and isolated at the same time, with small towns up in the Cascade Mountain Range that are perfect for desperate holdouts, alongside industrial mining operations and wood mills for varied locales.
For us, the Pacific Northwest is iconic and the visuals immediately root you in a distinct, recognizable, mysterious world.

Speaking of the Pacific Northwest, it is a very beautiful and lush environment, to say the least. Were there any specific tools in Unreal Engine 4 that really benefited the team in creating this stunning backdrop?
The landscape and foliage systems were both used extensively in the creation of our levels. The landscape system has many features that allowed us a lot of flexibility in the creation and editing of our terrain mesh. In some cases, we sculpted terrain by hand, while in other cases, we used a third party software to create height maps. In either case, they were easily modified with the sculpting tools provided if a revision was necessary. This flexibility also extended to the painting of materials on the landscape.
The foliage system was another tool with immense flexibility. It allowed us to quickly place large amounts of foliage with ease but also provided functionality that allowed us to tweak individual foliage assets when needed. Again, as revisions were needed in the development process, the tool allowed us to replace assets that are used across a map with a few easy steps.
In addition to providing a great workflow, both of these systems provided us with many avenues for optimizing our performance. The landscape tools offer ways to adjust LOD’ing the entire landscape or portions of it. The foliage tool provides a variety of tools to aid in optimization including distance culling by foliage type.
These systems were invaluable to our process, and definitely made our lives easier!

Inevitably, Earthfall is going to see some comparisons to the Left 4 Dead series. How did you use that inspiration and twist it around to make Earthfall truly unique?
First, we started this project because we were huge fans of Left 4 Dead, so we had a very strong vision in mind when we started designing the game. But when you go back and play Left 4 Dead, it’s missing 10 years of innovation in the shooter genre! So we were more guided by our memories of Left 4 Dead than the actual game. The result of that is something that is completely new and yet instantly recognizable.
Beyond the basic gameplay, we also changed the setting, moving from a present-day zombie outbreak to an alien invasion in 2031. We did this because we’re hoping to be evolving Earthfall into the future, and for that, we needed an enemy to evolve with it. While the aliens start as ravenous, mindless creatures, you’ll find out there’s more to them as you play, and we’re looking forward to telling that story as we introduce new aliens for you to fight, and new weapons to fight them with.
Earthfall is a high-intensity action game, but if you keep your eyes open, you’ll see clues in the environments as to what’s coming in the game, and as you unlock lore items in the game, you’ll uncover the backstory of the world and the aliens.
Finally, there are lots of moments when the players are just trying to hold out and survive, and we wanted to give them some interesting tools to define and control the battlefield. Being set in the future, we have auto-turrets that can watch your six, mounted guns you can man to mow down the enemy, and deployable fences to barricade off areas and channel the aliens into kill zones. You can even upgrade the fences with propane tanks to make flaming death traps, or arc grenades to electrify them.

The alien enemies in the game are dynamically generated but how much of their behavior dynamically adapts to players' play patterns?
We have a number of ways that the AIs modify their behavior to encourage teamwork and keep players engaged. For example, some of the AIs will intentionally focus on a player who’s straying from the group, so if you’re a lone wolf, you’ll want to keep alert! Others will focus on players that haven’t had much action in a while. Some AIs will attack a target with singular determination while others can be drawn away by a teammate. The AIs will change their aggression depending on the overall group’s progress, so if the group is tearing through a level with guns blazing, they’ll quickly draw the attention of nearby enemies. On the other hand, if a group is moving very slowly, some of the AIs might be dispatched to hunt the group and prod them along. This all ties back into the AI Director, which is constantly striving to create a steady ebb and flow of intensity for the group.
Continuing with the enemies, not only are they terrifying to look at, they come at you in absolutely insane numbers. How did Unreal Engine 4 help you bring these aliens to life exactly how you wanted them to be?
Unreal Engine 4 comes with a number of built-in systems that we were able to leverage to get things running at a high level very quickly. This allowed us to focus on the actual AI and gameplay very early on. Blueprints, in particular, were invaluable for prototyping.
We make extensive use of the built-in navigation system. This includes dynamic navigation mesh modification, path-finding, support for multiple agents, path filtering, and even AI movement. For the actual AI logic, we make use of Unreal’s perception, behavior tree, and Environment Query systems. These systems tie into very powerful debugging tools such as the visual debugger and gameplay debugger. This was a huge help in refining AI behavior and identifying and fixing issues that arose. We were then able to build on these systems and tools to deliver game-specific functionality.
For animation, we use a combination of animation Blueprints and montages. These tools help us bridge the gap between raw animation and the AI system to deliver a compelling performance.

Earthfall has a diverse cast of characters. What brought these four together and how important was it to Holospark to bring that diversity to the table?
When we started thinking about our characters, we started off by thinking about Seattle archetypes and building our characters from there. We didn’t start off to make a statement as much as we were focused on telling a great story with memorable characters. It’ll be nice when the day comes that having different races and ethnicities isn’t exceptional and that people view the story on its own merits.
3D printed weapons! While that alone is a pretty fun mechanic, how do you develop that in-game and are there any surprises awaiting players as they advance through the campaign?
From the beginning, we knew that we wanted to set the game in the future so we could give new capabilities to the players, and the 3D printer was a natural fit. It gives us some natural objectives in the game world (“get the power back on to get the printer working to print those sweet weapons!”) and good checkpoints to resupply your weapons.
In the game, you’re exposed to the printers as just an expected part of the world, but you’ll find some info into why they work the way they do. We’re looking forward to expanding their operation in the future!

What advice you would give as experienced developers to someone who is in the beginning stages of learning Unreal Engine?
Unreal is amazingly accessible. First of all, it’s free, so there’s no cost barrier to jumping in and getting started! Second, it comes with great tutorials that take you through the basics, and sample games that will really show you how everything works in a functional and practical manner. Beyond what comes with the engine, there’s a staggering amount of information on the web to help you learn Unreal Engine. With so many developers using the engine, there are countless “how to” videos on Youtube on almost every aspect of the engine and tons of in-depth articles to read on sites like 80.lvl. It has never been easier to jump into game development.
Where are all the places people can go to learn more about Earthfall?
You can go to www.earthfall.com, or follow us on Twitter and Facebook to stay up to date!
EDITOR’S NOTE: Unreal Engine caught up with Holospark during E3 2018 to learn more about Earthfall. You can watch the video interview below.