We’ve covered a few of the different systems in The Last Of Us Part 2 recently. There’s the sound design for the Shambler Infected, the whistles of the Scars, and even the fact that Lev’s name comes from a book that inspired the series. Today Sound Designer Beau Anthony Jiminez has produced a thread on the breathing mechanics in the game, and we’re going to dive into those.
#TheLastOfUsPartII’s Breathing System Thread Part 1
One gift of working at Naughty Dog is that the sky is limit. With artists and programmers collaborating closely, magic can happen.
The Breathing System is an example of that magic.
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— Beau Anthony Jimenez MPSE (@thebeauanthony) July 18, 2020
He first discusses murmuration, which kicks in when you’re doing something active. Certain actions will turn it off though, such as aiming a weapon, but the loop will pick up again afterwards, which achieves a nicely looped breathing cycle that sounds realistic. Apparently it’s called Murmuration because it’s the sound under the sounds. So for humans it’s breathing, but for Clickers and Shamblers it would be the form of clicking that they do, or I suppose straining for breathe.
Murmuration is a looping sound on a character. It's the lowest priority sound possible, so any sound that triggers (from melee, anim, script or code) will stomp it. After the oneoff plays out, the loop will return where it left off, creating a seamlessness in the breath.
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— Beau Anthony Jimenez MPSE (@thebeauanthony) July 18, 2020
Heart rate is actually a big part of the breathing in the game, even though the characters aren’t technically alive. Jiminez explains that he added a heart rate monitor that valued different levels of exertion to Ellie and Abby based on what they’ve been doing. This monitor also exists for every living creature, including the Infected.
Programmers helped Jiminez split up the states he needed in the game, and he was able to assign different breathing levels to them all. It’s even used on attack types, such as the Bloater’s charge. Clickers have various states that affect their breathing, with frenzied or unaware being just two of the polar opposites you can encounter.
Using all of these various states, it was possible to put together the sprinting breathing noises for Ellie and Abby. It makes the sounds more accurate depending on how hard and long the characters have been sprinting for. You’ll notice it if you run for a good long while with Ellie, and then battle through a bunch of enemies. She sounds ragged by the end, and it’s very different to taking down groups of enemies using stealth.
If Ellie starts sprinting when the enemy is aware of her, you'll hear Ellie's sprint breaths become increasingly feverish and fatigued.
These are her Stages.
Every tension has 3 stages of assets, varying in intensity.
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— Beau Anthony Jimenez MPSE (@thebeauanthony) July 18, 2020
You also get a really good idea for how this system is used in the following video.
In this video, I scripted a spike in Ellie's Heart Rate when she progresses through this squeeze-through to showcase her fear.
This blends beautifully with the gameplay dialog which triggers after Ellie grabs the pipe!
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— Beau Anthony Jimenez MPSE (@thebeauanthony) July 18, 2020
The system becomes even more complex when you realise that there’s an entirely different set of breathing mechanics for Ellie breathing with her mouth open or closed. It completely changes the tone of an encounter, and now that I think about it, I noticed this a lot while playing the game.
One note-worthy feature is the Open/Closed Mouth Stealth Breathing, Mike Hourihan's (@m1keadelic) brilliant idea! If the enemy is within a certain distance and in the player's view frustum, Ellie will transition to closed-mouth breathing.
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— Beau Anthony Jimenez MPSE (@thebeauanthony) July 18, 2020
Abby has vertigo, meaning she’s afraid of heights. Breathing played a small part in making it feel like the character was truly broken when faced with a height, and you can see just how effective that is in the sound design below.
Abby's vertigo was also integrated into this system. The vertigo game data that affects the camera talks to the audio middleware to play different breathing if Abby is looking over a ledge. The volume & intensity is affected by how much or little you're looking over!
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— Beau Anthony Jimenez MPSE (@thebeauanthony) July 18, 2020
Finally, we have breathing while injured. It works really well as a way to signpost to the player just how damaged Ellie is, which is integral to keeping track of health. It’s also a great way to flag when Ellie probably has an arrow sticking out of her shoulder or something.
Injured breaths are integrated into the system as well.
A flag is set when there's an arrow embedded in the character or if player's health is low. That enables my scripts to potentially play an injured variant integrated into the the base systemic breathing variants.
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— Beau Anthony Jimenez MPSE (@thebeauanthony) July 18, 2020
There’s a lot more to the breathing system, and I didn’t want to bombard you with it all in one post. So keep an eye out tomorrow morning when we’ll have a little but more about how breathing was done in The Last Of Us Part 2.