Give teenagers an FPS with a toolset and you can count on them to start designing levels based on environments from their own lives. It was the source of no small moral panic in the ‘90s, when Doom levels were traded under the noses of parents, and Sean McAlister was doing the same a generation later with Halo 2.
“The PC beta had a map editor that came with it, and they allowed you to make completely custom maps,” McAlister tells us. “Back when I was 15, I made a map of my backyard in the game. It was just fun to drive around it and see that familiar location in a different context.”
McAlister grew up and joined the army. But one day, while lying in the long grass at Fort Knox in Kentucky waiting for training to resume, he found himself thinking of his backyard again.
“I remembered setting up these little plastic army guys with other toys, playing out scenarios, and just using my imagination,” he says. “And I guess we lose that as we get older, a little bit. We don’t have that kind of downtime, and that boredom brings out the best of your imagination. I thought it would be an interesting idea for a game.”
What began as a Homeward Bound-esque single-player campaign that would take players through McAlister’s childhood backyard is now an open-world game named Plastic. It’s set between the sandcastles and plastic brick settlements of a real-life, if reimagined, location.
Rebuilding the backyard
McAlister has reassembled his backyard in Unreal Engine 4 using a combination of Google Earth data and photogrammetry – the technique in which real-life photographs form the basis for 3D game assets, creating the astonishingly realistic art seen in the worn armchairs of The Vanishing of Ethan Carter, or the Californian redwood trees that sell Endor in Star Wars: Battlefront. It’s not a technique so often associated with solo developers.
“To be honest, when I first started using photogrammetry for assets, I was struggling to get all the angles and work with RAM restrictions on my computer,” McAlister says. “I have definitely struggled with the programming side, too – fortunately Unreal Engine 4 has Blueprint visual scripting, so I haven’t had to rely as much on C++.”
For Plastic, McAlister has scanned in garden objects up to the size of a basketball – and where he hasn’t been able to incorporate the data directly, he’s used it as reference.
“Photogrammetry doesn’t work super well on more complicated shapes that are convex or have a lot of nooks and crannies,” he says. “My little siblings would often come with me outside, hold the tape measure for me, and I’d measure everything to make sure it was right. It’s pretty faithful.”
A level called home
McAlister has taken some artistic liberties for the sake of the game – the grass is shorter than it’s normally cut, so that it isn’t blocking the third-person camera. But the layout of the yard hasn’t come into conflict with third-person shooter level design as often as you might think – and that’s mostly thanks to Plastic’s miniaturised scale.
“You’re playing as a plastic army guy, so the world is stretched out,” McAlister says. “If this were a normal FPS, things like fences and the locations of trees would be major concerns. But most of this land is flat, and most of the obstacles are the toys themselves that I add in.”
That said, the human-scale objects in McAlister’s yard have come in handy as local landmarks. Plastic employs a depth of field effect, similar to that seen in Cities: Skylines, that mimics tilt shift photography and gives the game a toy-like appearance. A side effect, though, is that objects in the background are often blurred.
“Because of that, a lot of the larger assets become navigational points for the player,” McAlister says. “I think that will help a lot. I’m definitely glad that there are a lot of these large vertical structures in the game, like the basketball net, that are visual cues. As you get to play the map more, you’ll know exactly where you are every time.”
Of course, McAlister’s family already know exactly where they are when they play Plastic.
“It’s almost like an uncanny valley type situation,” McAlister says. “I’m pretty sure nobody else will feel what I feel when I play this game, or what my family feels. They’ll just be like, ‘Oh, that’s a backyard’. But I know my family has gotten a big kick out of it just going around saying, ‘Oh, you put that in there?’.
Plastic is coming to the PC. 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 Sean McAlister.