Despite Dead Island 2’s glamorous outer shell—its sparkling, sprawling vision of L.A., filled with scattered cash and ruined mansions—what makes it compelling is making its many zombies literally spill their guts. As you may have once heard, it’s what’s on the inside that counts.
So on Friday, Dead Island 2 developer Deep Silver answered questions on Reddit about its procedural “flesh system,” which allows players to shave off zombie parts methodically like digging through ice cream to get to the caramel core, and is directly responsible for the game’s nasty satisfaction. It has its limits, though.
“I’m not sure I’d want to see it on believable human enemies to be honest,” Dambuster Studios technical art director Dan Evans-Lawes said on Reddit about applying the “flesh system” to other video games. “We deliberately kept it zombie-only so we could go super extreme with the gore without it getting too disturbing.”
While Dead Island 2 undoubtedly delights in violence, keeping it unreal and undead helps establish it as a technical and artistic feat. You can be more convinced that it exists for entertainment, as appropriately over-the-top B-movie splatter that wouldn’t necessarily be an ideal fit for every violent video game.
Here are eight of the juiciest details (lightly edited for clarity) we learned from Deep Silver’s in-depth ask-me-anything session.
Read More: Let’s Break Down Dead Island 2’s Gnarly, ‘Anatomically Correct’ Flesh System
1. The “flesh system” was more inspired by films like RoboCop than real-life violence
“When I was doing the skin/fat/muscle blending I looked at some real pictures of surgery because you actually get a much clearer look at the structures and colors that way,” Evans-Lawes said, “but in terms of the end results we wanted to achieve, I mainly looked at practical effects in movies such as RoboCop, Starship Troopers, Day of The Dead (and many more).”
“I completely avoided watching anything involving real violence towards real people,” he continued, “partly for my own mental health, but also because our goal was to make the violence so over the top, it was ridiculous and entertaining. We weren’t going for [something] disturbingly realistic.”
2. Zombie flesh is “infinite” in its ability to break down
“The surface of the flesh is pretty much ‘infinite’ in terms of variation, limited by poly count and texture resolution, basically,” said senior render programmer Aaron Ridge. “Internally, we have many ‘viscera’ chunks, which can be individually destroyed.
The head has some special rules to avoid some chunks floating, so we always have some attachment to the spine remaining. If we dismember or bisect a zombie it always has to be a complete cut; we don’t support making a zombie nearly-headless, although that would be cool.”
3. Cutting into bodies is kind of like cracking a chocolate Kinder egg
“Zombies are built out of a surface mesh and a set of ‘viscera’ meshes,” Ridge said. “The viscera meshes are individual pieces that can be destroyed, or broken. This is a shared asset among zombies, with a few variations on viscera. The viscera itself comes in as one model, but we split up the draw call when we break it apart to attempt to keep draw calls minimal.
“The surface mesh gets deformed and modified as the zombie takes damage. When we do limb dismemberments or bisections, we dynamically split the mesh across a cutting plane, testing each triangle to determine what side it lands on, and then we use the secret ‘Kinder egg man’ technique to close it up and detail the wound.”
“I’ve seen people claim dismemberments are pre-cut, but this is only half true,” he continued. “The viscera which makes up the bones is split into fixed pieces, but the mesh is dynamically cut so the direction and position of the cut can freely change between cuts.”
4. Some of the bone-snapping you hear is actually spaghetti
“The audio team destroyed a lot of vegetables and snapped a lot of spaghetti in order to make all the gory noises in the game,” Evans-Lawes said. “In terms of visual research, we didn’t actually hack any meat to pieces with machetes, but it’s definitely something to try in the future, I think.”
5. It’s surprisingly difficult to hole-punch zombies
“Hardest part was probably figuring out a way to make holes through the zombies,” Evans-Lawes said. “Our initial implementation had a solid ‘core’ that you couldn’t damage, but we really wanted to be able to blast holes straight through.
Part of this was giving the outer flesh some actual thickness rather than it being a wafer-thin, single-sided mesh, and the other was filling the resulting hole with destructible guts.”
6. There could have been frozen zombies
“At one point, there was also talk of freezing zombies, but that one never really made it off the drawing board,” Evans-Lawes said, “partially because we quickly maxed-out the number of textures we could look up in a single zombie material.” But “it would definitely be something I’d like to see,” he said in a later comment. “Who can forget the legendary liquid nitrogen scene from [2001 sci-fi slasher] Jason X?”
7. Stop trying to look at zombie boobs
“Zombie clothes do burn!” Evans-Lawes responded to a question about Dead Island 2’s lack of nudity, particularly on zombies whose bodies can withstand heat. “However, if you look closely, you will find that zombies do wear perma-pants to protect their modesty.
In the case of [boss character] Butcho the Clown, we had the issue of him regenerating, but it wouldn’t make any sense to regenerate clothes, so in that case, we did actually make the top of his clown trousers indestructible.”
“I think you’d struggle to do just the right amount of damage to expose the bits you’re so eager to see anyway,” Ridge said.
8. “Photo mode” isn’t entirely out of the picture
“We’re definitely hearing a lot of love for the idea of adding photo mode,” Ridge said.
“Yeah, it’s been great seeing the community taking all these close-up shots of the detail we put in as we did sometimes wonder whether anyone would actually notice it during gameplay,” said Evans-Lawes. “Can’t promise anything on the photo mode yet, but we hear you!”