Breasts swing. They sag. They flop. They can move. Over the years, many games have tried to emulate the way breasts behave. There’s even a term for it: “Breast physics”.
This story was originally published in February 2015
If you’ve played games that have breast physics, you’ve probably seen how uncommon it is for games to show breasts that move like what they actually are: bags of fat affected by gravity. Instead, it’s more likely for a game to depict breasts as helium balloons that have minds of their own. Certain games have failed at rendering realistic breasts so widely that some people seem convinced that bad breast physics are the result of sexism, or of an industry that likes to objectify women. I’ve seen unfair conjecture about whether or not developers have ever interacted with real-life breasts. I’ve seen people imply that developers simply don’t know how to properly characterise women in games, and that gaming’s ocean of unrealistic breasts is what happens when we have so few women developing games.
Are any of these sorts of claims true, I wondered? Plenty of people theorize about why games often feature bad breast physics, but there is little hard information about the actual breast-creation process. After looking into it a bit, I found that many amateur developers seemed to genuinely have a problem figuring out how to tackle breast physics in their games. There are a startling number of forum posts and tutorials where people discuss the best ways to achieve good breast physics online. One person even created a four-part Powerpoint presentation titled “The Quest for Boob Jiggle In Unity.” People have developed specialised tools for other developers to use, to help demystify the enigma that is “how do breasts work.”
Meanwhile, veteran game developers have been messing around with the way breasts move for almost two decades now.
1996: It Begins
In 1996, a fighting game called Fatal Fury 2 was released. Described by some as a “blatant clone” of Street Fighter II, Fatal Fury 2 did actually have a few noteworthy quirks of its own: it was a gorgeous-looking game that allowed players to perform “desperation moves” when their health bar was low, and it gave players a chance to get out of danger quickly through a hopping mechanic.
But let’s be real. One of Fatal Fury 2‘s biggest contributions to the medium was that it was the first game to introduce a character with breasts that moved on their own.
(Source: TheInnocentSinful1)
Known as Mai Shiranui, that character is famed for having very, uh, lively breasts. Though Fatal Fury may not be a huge franchise nowadays, its legacy is very much alive: many top fighting games include a similar jiggle effect:
Street Fighter 4
(Source: CeruleanNight)
Soul Calibur
(Source: Thegamerwalkthroughs)
Skullgirls
(Source: Poccola_margherita0141)
Of course, fighting games aren’t the only games that have wrangled with breast physics over the years.
Tomb Raider
(Source: sys2074)
Resident Evil
Metal Gear Solid
(Source: Saladtoser69)
Ryse
When developers don’t include breast physics, it’s not uncommon for savvy players to take matters into their own hands via modding. A popular type of Skyrim mod adds most robust breast physics to the fantasy game:
(Source: Marek Iwanowicz)
In 2009, there was also a Second Life mod that allowed players to add breast physics to characters. It became so popular, the actual game ended up incorporating the same feature — and now players try to advise each other on how to fiddle with their characters to achieve the best effect.
(Source: BlakOpalDesigns)
Even Minecraft players have figured out ways to add breast physics to their game. Then again, Minecraft players have tried their hand at adding pretty much everything to their games, haven’t they?
The Most Famous Breast Physics of Them All
When it comes to breast physics, the most notorious game of them all has to be Dead or Alive. While breast physics might just be a minor ‘feature’ in the games I mentioned above, for Dead or Alive, breast physics are woven into the identity of the game. That emphasis might give the games a bad rap, as Mike Fahey argues in his piece about Dead or Alive, since fans find plenty to love in the way the game plays, some of which have nothing to do with breasts. Still, you can’t really divorce Dead or Alive from its breast physics.
(Source: Thegamerwalkthroughs)
“I wanted to do something that would attract people’s attention as I worked on the DOA game,” Itagaki said in a Game Informer interview from 2004. “Of course, DOA is known for its bouncing breasts…when I applied [breast physics] to a 3D game, it was almost too much for people.”
One of the big selling points for the latest game, according to the marketing at least, is the new engine — which will allow players to adjust the breast physics on their characters.
“We call the technology we used to advance skin and breast physics and make that a reality, the ‘Yawaraka Engine,’” Yosuke Hayashi, producer on Last Round, told Famitsu. “Once you see it on the new consoles, you won’t be able to go back.”
What they’re saying: thanks to the power of technology, the development team has realised more complex breast physics. The marriage of technological prowess and sexuality is a curious one…of course, anyone that watches footage of Dead or Alive knows that the series doesn’t care about realistic physics, not really. Instead, the game has always featured outlandish physics, both for the breasts and for the gravity-defying fighting moves. Whatever misgivings people have about the realism of the breasts, the intense physics seem like a deliberate choice meant to realise a particular aesthetic.
Can the same be said of other games? I’ve spent the past few months trying to talk to developers about breast physics. It’s been surprisingly difficult getting people to talk — I’ve had an easier time trying to poke people for details about high profile unreleased games than I have asking them about why games depict breasts the way they do. Despite speaking to a number of developers on the subject, only a few would speak to me on the record. Fortunately, I’ve managed to get a basic handle on how breast physics work.
How Video Game Breast Physics Work
Basically, in a modern game with 3D graphics, each character has a model. Underneath the textures that cover them like a “skin,” these models are made up of “bones,” which can be manipulated so that the character can move. The number of bones a character can have depends on the game’s graphics engine; certain engines allow for more bones than others. The number of bones a character has also depends on the overall number of characters rendered at any given moment — the more characters there are, the more taxing it is on whatever hardware is processing the game, so the fewer number of bones each of these characters is likely to have. (Thankfully, real life doesn’t work this way!)
All of these bones are prepped to be animated via a process called “rigging.” Rigging allows developers to determine the extent to which a model can move, and how. Breasts don’t generally move of their own volition, they move in reaction to something else, much like hair and clothes do. If a developer wants breasts to move, then they will likely “rig” a character’s chest area. How the breasts move depends on how many bones are in the bosom area: when breasts both move in unison, it’s likely that the model’s chest has a single joint. If both of the breasts move independent of one another, the chest likely has at least a couple of bones rigged.
(Source: Maya Learning Channel)
“Mechanically, breasts anchor off the pectoral but loop up and connect at the shoulder, so they get pulled back when the clavicles move,” Tim Dawson, an indie developer that has previously worked on games like LA Noire, told me.
Once breasts are rigged, developers can add breast physics in a couple of ways. Breast movement might be dictated by a simulation system that lets developers add “springs” to breasts. These springs take motion and use it to determine how much something should move after, say, a character jumps up and down. Springs help make it so that breasts can continue to move even after a character becomes still. If a character has two springs, one might be used to determine how far a breast bone is distanced from the sternum, and a second spring might control how much the breast deviates from its starting point. Then, on top of all of that, developers can add a dampening effect that determines how long it takes for the breasts to settle down.
“Imagine the character standing up,” Dawson said. “The sudden movement would pitch the breast bones downwards. Then when the character reaches their standing height, the bones catch up, pitching upwards slightly, then back down and come to a rest. This would be a procedural breast bounce and settle. The rest just comes from thinking it through: how much heft are [the breasts] likely to have, how well-supported are they?”
Why Developers Get It Wrong
I’m told that a good number of games use this system. Thing is, a spring system isn’t necessarily effective in creating realistic physics, but it is considered a cheap, easy solution to add breast physics. Some engines even come with it built-in. Spring systems are meant to help with something called “rigid body physics,” and, well, breasts aren’t rigid. To create realistic breasts, you’ll need something called “soft body physics simulation,” and it’s a lot more taxing for a computer to calculate.
Another way to add breast physics involves animating the breasts by hand — that is, the breasts would be treated no differently than other major body parts, like arms or legs. In this case, the breast physics aren’t left up to a simulation system but instead determined on a case-by-case basis by an animator. I’m told hand-animated breasts are rarer than a sim system, due to how time-consuming it is. Animating breasts is a real handful, so to speak. (Sorry.)
While those aren’t the only ways to animate breasts, they help explain a few things. Why distinct breast physics are so prevalent in fighting games, for example: when you only have to worry about two characters on the screen on any given moment, of course developers can add details like breast physics. Fighting game characters characters can likely have more bones than characters in an average game. The difficulty of crafting breast physics may also explain why so many games have strange-looking breasts: developers who are interested in adding this detail can’t financially justify doing so, so they have to cut corners any way they can.
Still, it’d be a stretch to suggest that unrealistic breast physics are purely the result of technological shortcomings. Breast physics are a choice, after all, and not every game implements them.
One developer who I’ll call “Alex,” because they didn’t want to be identified by their own name, told me about a situation where breasts had gone wrong — and it wasn’t the result of tech limitations. Alex told me that their studio was very concerned with its depiction of breasts. Even so, there were stumbles along the way.
“The very first thing I noticed when [the studio was] animating breasts is, I would look at them, and they were just not moving in a way that was even remotely natural,” Alex said.
“I remember saying to the artist, ‘the breasts are moving wrong.’ And I remember directly asking him, ‘Have you watched breasts move? Have you actually watched breasts move?”
Chances are good that the animator in question had in fact seen breasts before. The thing to remember is, it’s actually damned hard to remember how breasts actually move. As a card-carrying Breast Haver™, even I’d have to check how my breasts act before being able to properly gauge them in a game. Of course, it’s an animator’s job to figure this stuff out.
“I think [people] remember the fantasy of breasts, like how we remember lips being redder, how we see waists as [smaller than they actually are,]” Alex explained.
“If you’re around animators working, you often will see them stand up, or they will ask someone they’re working with — they’re trying to watch the motion, they will film themselves doing that motion. Interestingly enough, I’ve never worked with any female animators.
“Anyway, while doing these things, [animators would] swing their arms, and try to get an idea, they’re looking at what the animation is like, and I think…breast physics are often accentuated in a game, without the movement that would create that accentuation.”
“People remember the fantasy of breasts.”
Absurd breast physics aren’t always unintentional, though. A couple of developers described situations to me where people took breast physics too far on purpose, because if they put the work into making sure breasts can move, they’re probably going to want people to actually notice it. This phenomenon is not exclusive to breasts. If a developer puts time into any detail in a game, they probably want players to notice it. That’s why we get development videos about how a game handles things like wind, or how a character’s cape sways: these aren’t the sort of things that truly determine the quality of the game, but they are things actual humans likely spent a lot of time implementing.
“When a developer goes to the trouble of setting up the breasts to move, there’s probably someone keen to see it working,”Dawson told me. “So, if you’re not careful, that translates into breasts that swing and bounce at the smallest hint of motion. Picture the boss of the studio coming in and wanting to know why he can’t see any breast-bounce when the character is talking. The effect is increased until her breasts are reacting to the chest movement of her dialogue animation, but now it’s going to look ludicrous when the character runs around performing actions. But the person implementing it is told to leave it like that because somebody thinks it’s cool that way.
“Ultimately though, I sort of suspect that when a developer doesn’t get breast physics looking right, it’s because, for whatever reason, somebody wanted them to look that way,” Dawson said.
Obviously, Dawson can’t speak for the decisions made at studios he doesn’t work for, but what he’s saying makes sense. Soul Calibur developers, for example, have been pretty open about the fact they have an entire system revolving around the depiction of breasts in their games:
There’s no doubt there that they very much want the breasts to look and function the way that they do. But just because it’s intentional doesn’t mean it will be received well.
“Every other woman in the universe has sort of a cringe reaction, you know? ‘Boobs just wouldn’t move that way. That’s not natural’” Alex said. Alex would know; at Alex’s studio, the models were all focus tested. The developers actually received feedback from women who saw the game. While it may not be typical for most studios to do this, in this case, research was conducted because there weren’t many women game developers on the team that could weigh in on the subject.
“Across the board, [the response from women] wasn’t a neutral response, it was a negative response,” Alex said. Curiously, the negative response occurred both when the physics were unrealistic, and when the physics were turned off. It seems as if there’s a very fine line to walk when it comes to breast physics: they can’t be too exaggerated or too toned down without having people feel as if something is wrong. You might think of it as “the uncanny valley of breasts.”
We Like It Like That
It was through focus testing, the usage of good reference materials, and honest conversations about anatomy that Alex’s studio was able to improve their breast physics. But, when I say “improved,” I don’t necessarily mean “made more realistic.”
“Many games are full of exaggerated [male] forms,” Alex said. “We don’t point at those and go, huh, that doesn’t look realistic at all. Of course it doesn’t! It looks superpowered, and we like that. The same thing would apply to breasts.”
Tim Dawson seems to agree. To him, developers tend to include unrealistic breasts, because exaggerated bodies have become a staple of the medium.
“The developers might be playing fast and loose with their anatomy, like breasts that are too large or too unsupported for what the character does, or that are just in an unnatural shape,” Dawson said. “I once received a female enemy model that appeared to have balloons protruding out of her torso and couldn’t convince the art director that it needed fixing.
“But even when well-modelled, if a character with breasts the size of watermelons is wearing a metal string bikini and attacks enemies with cartwheels, it’s going to be hard to make the breast physics look realistic because the scenario is not realistic,” he said.
“People like the movement of breasts, that’s a hard-wired thing in our heads,” Alex said. “So, for some people, exaggerating that is a net positive. I think [breast physics] are in games for that reason.”
Ideas For Game Developers
Regardless of whether a studio is going for realism or digital beauty, there are still video-game breasts that look good, and breasts that look ridiculous. Game developers can do some things to help swing more toward the latter.
“Just run it by a few people, run the animations by people,” Alex said. Alex emphasised to me that this was particularly important if the studio doesn’t have many women.
It’s also worth considering what kinds of breasts the game has on display. Alex pointed out that there’s a difference between natural breasts and augmented breasts. A person’s specific body-type can influence how breasts move, as well. Some people are bigger than others, and this affects the way their breasts move. Some people have breasts situated at different heights on their chests. Some people have perkier breasts than others. The list goes on. “Even the absolute best natural breasts have some sag,” Alex said. It’s important for developers to think about these things, if they’re interested in better breast physics.
Another thing that Alex suggested was for development studios to make use of porn, particularly older pin-up nude magazines. Really. It’s apparently great for reference material.
“[They give you] a really good opportunity to see, ‘where is the nipple placed? Where do the line on the chest? What is the curve underneath?’
“I don’t [think] breasts need to be realistic in games, unless that’s what [developers] are going for…but [developers] should be aware that if the breasts are moving in a weird way, then it just becomes the uncanny valley for women.”
With these things in mind, maybe games can get better at depicting breasts. And when that happens, maybe the game industry can move on to figuring out the mystery that is…dick physics.
“If I were animating a naked man walking, I really honestly have no idea how balls move,” Alex joked. “I don’t!”
Picture: Jim Cooke
Comments
50 responses to “How Video Game Breasts Are Made (And Why They Can Go Wrong)”
As an illustrator, it’s taken me years upon years to get the proportions on breasts right. Breasts are just really hard to get right in any medium. Lol, these days I only draw young characters with small to no breasts when I have to…
Yeah. I’m not defending the more ridiculous cases but in games like Tomb Raider and Resident Evil it looks equally ridiculous when they don’t move at all or when they’re animated by hand (and thus ignore physics entirely). Getting realistic movement out of stuff like hair, cloth, tits and body fat is way harder than it seems.
Now that you mention it, hair physics could be improved too. Too many times, ponytails act like they’re made from tissue paper streamers.
My guy in Destiny, which apparently has awesome hair, looks like he shaved his head down to a one then stuck a whole pad of post it notes to it.
Now I think about it making hair move realistically in a vacuum is probably one of the hardest things you could do.
It will be funny when lady game developers create a satirical game with excessive and impossible wang physics. Not that I’m into that sort of thing. Stop looking at me.
Forget I said anything. Get back to the boobs.
You might be interested in an odd little title called Mount Your Friends.
You need to play Mount Your Friends.
Beat me to it! Played it with my fiancee, that was interesting.
re – Mount your friends for those who don’t know what it is
I…wish I hadn’t watched that…
They have physics for tails already. The wang would work exactly the same.
No it would not. A Wang is pure muscle. Most tails are bone and muscle. The theirs the ball sack, witch would prob be as hard as tits to do.
Personally I generally prefer it if games just didn’t try animate them at all.
Sure there’s merit in trying to develop the technological tools to simulate it, but in most games with boob physics, it’s really not necessary.
From what the dev was saying having no animation is just as bad. It just seems wrong, like lips not moving in sync with the dialog (or mouth not moving when speaking)
So it should be done, it’s just a matter of how.
two words: sports bra
Even a sports bra doesn’t hold them in place with no movement. But smaller breasted models and actual clothing would reduce the issue.
I definitely give more of a shit about the lack of actual clothing (and realistic fabric) than perfection of the jiggle.
But fabric and textures have come an extremely long way, where as just by looking at Ryse’s efforts, you can see that boobs haven’t.
Oh, this is true, but the tendency for video games (and comic books, generally the worse offender when it comes to “fabric” tbh) to dress female characters like they’ve been vacuum-packed into their outfits would make realistic breast physics more forgiving.
Sports bra, bikini, halter top, unsupported (topless). Silicone implants or natural. Full size or tissue padded.
When in doubt, hire some models and do motion capture. Heck, splice the mocap with the animation and include it as a download. Disney filmed real ballet for “dance of the hours” in Fantasia – how many years ago was that?
Hmm I disagree with the dev on that point. Lots of games have bad animations that I’m willing to overlook. Animations have come a long way over the years, and it’s not as though the older games were unplayable just because they weren’t animated well.
Basically, my opinion is that bad animations are worse than no animations at all. But that’s just me.
I would agree with that, but good or even ok animation is better than no animation
With bad animation you can see what is wrong but with no animation you get that, something it wrong but I’m not sure what feeling,
Disagree with the dev and the focus group of women they brought in to rate it, too.
Kind of a weird stance to take. Why?
I guess it’s mainly about the impact of the animations, which is totally subjective.
For me, i find badly animated stuff quite off-putting. I can deal with things that are simply animated, and just kind of ignore them. But when they put time into animating something and it’s just not quite right, that bugs me.
Not saying anythings wrong, just a personal preference.
Like when the running animation is too fast or slow in relation to the ground being covered, you get that annoying escalator effect.
It’s like when you play an older game 3D game that aims for realistic graphics but is full of character who stand perfectly still when they’re not doing anything. It doesn’t quite register what is wrong, but unconciously you pick up on the fact they’re not breathing. Especially now we’re all so used to characters not being action figures.
That manw**** logic. The difference here is that the exaggerated males tend to embody power fantasies as opposed to sexual ones. If games had as many bulging crotches as they do bulging chests, then he’d have a point.
I assume this is some sort of insult that got censored?
Wrong, you idiot, (see I can do insults too) they are both sexual you are just too wrapped up in your moronic world view that you cannot understand that.
You see the human species is sexually dimorphic, that means that the sexes are different physically, also mentally (take that as an insult if you wish). Females of the species are sexually attracted to physically strong males because that equates to being good protectors and providers and their children are also likely to be strong. Males of the species are attracted to females who can give birth easily, wide hips -> shapely buttocks, and provide sustenance to the offspring, good milk supply -> large breasts, smooth clear features also mean they are likely free of disease.
The size and shape of a male “crotch” has little sexual attractiveness to most females, there are always some deviates, it is generally believed that the size and shape of the human male reproductive organ has to to with trying to remove other males deposits from unfaithful females and get his further in.
Power fantasies have nothing to do with most men bulking up, they are trying to be sexually attractive. Just because females of the species think, “look at the strong powerful man”, does not make it a power fantasy from the male point of view, it is a sexual fantasy from both genders because the female is also thinking “he is getting me all hot and horny”.
Thanks for writing all that so I didn’t have to. I can’t believe people are still talking about this sexism vs power fantasy stuff, it’s so illogical.
The square brackets are added by the editor, not part of the original quote. Alex isn’t talking about gender differences, he’s saying that realism isn’t a requirement in video games, and that most human forms are exaggerated. He does have a point, because games are fiction and art, and there are no stringent realism requirements when it comes to either.
Most women I know find the arms to be their favourite part to look at rather than the dick.
Absolute disagreement here. Whether or not particular characters fulfill a power/sex (or both) fantasy is up to the viewer. The artist may be aiming for one or the other, but they draw from the same pool of inspiration and research; providing a different mixture of sexual proclivity and powerful presence each time.
And puhleeez – there’s no way breasts compare to male genitalia on the ‘naughty body parts to show on TV’ scale. However I’d have agree’d with you if game’s were overflowing with gratuitous cameltoe.
This was a pretty good article, except for that sentence: it seems unnecessary to me to adjust the sentence to specify ‘male’ fantasy, when clearly exaggerated physics would be present in all power fantasies.
Muscle development is a male secondary sex characteristic, just as breast development is a female secondary sex characteristic. Penises and testicles are primary sex characteristics (as are vaginas), it’s not at all reasonable to try to compare primary with secondary as greenwarpy did above.
And like you said, the idea of what is a sexual fantasy is up to personal interpretation. Some guys like breasts, some guys don’t. Some women like muscles, some women don’t. Suggesting muscles are exaggerated purely for power reasons and not sexual ones is just naive.
Can someone explain to me the difference between male power fantasy when a man’s sexualised in a video game, and female sexual fantasy when a man’s sexualised on, say, the cover of a romance novel?
Really the only differences I can think of is a) target audience and b) character actions (power fantasy does more beating up, sexual fantasy does more sexing up.
But on a visual level I think these burly man-figures are incredibly similar.
Not really, plenty of males would want bigger chests and huge muscles simply to impress the ladies. Just as some girls wish for bigger breasts to impress males. I see no difference.
Doesn’t the order have a nekked man wrassling segment, replete with wang physics?
Great article. As with all effects in games, it looks best when it’s subtle enough that most people don’t even notice it, but if it weren’t there people would notice something was missing. I always add boob bones and tummy bones if a character has a large enough tummy.
I agree. When the effects are really good, you don’t notice them, or it takes particular attention to notice them.
There is actually jiggle physics on most if not all of the characters in Soul Calibur. E.g Astaroth has thigh and pectoral jiggle (or he did in 3 or 4, I don’t remember which exactly, probably both). It’s harder to notice though, because it is subtle, and also because Ivy’s boobs are too distracting ;p
VOLDO…
All this research into boobs and they still can’t get them to look right.
Dude we’ve been researching how to make efficient fusion power for years and can’t get that right either.
Free the boobs!
Where are the women in this discussion? Your thoughts, please.
As with anything in art, it doesn’t have to look realistic, but it has to look believable.
The Order 1886 did it and it looked much better than the boob physics. (HA HA HILARIOUS AND CUHRAAAAZY and lol at everyone trying to say a dick is worth more than boobs; stupid argument, men have less stigmatized body parts) I’m not sure why you’d need physics for boobs today though. I mean, the point of most attire for women whilst engaging in physical movement is to minimize distracting movement. And who’s hard-wired to like breasts? a bunch of guys and girls? (and I doubt the girls would be so interested that they’d even tell anyone about it) Are homosexual men enamoured with boobs too? Are all girls hard-wired to like a flopping dick?
It was kinda funny seeing a bunch of blurry squares and triangles slide around in Dead or Alive but as character models get better, boobs become more irrelevant because the crazy shit you usually dress them up in looks ridiculous now. I’ll use The Order again; it’s a totally heightened style but no men are bulked up because it would look strange and women don’t wear bikinis, they actually just wear what everyone else does. Point is, you can’t even see them and if you’ve ever even seen an action movie starring a woman (Salt, Lucy, Fifth Element, ALIENS!, Jupiter Ascending, FEMALE WRESTLING) there is no noticable jiggle. THERE IS NO JIGGLE, PEOPLE! There are insane excuses here like “they jiggle a bit, even with a sports bra so it needs to be done.” Wha’?! Look at her face, that’s your failing.
I don’t think REmake should be taken back and changed because for better or worse the old style is part of its charm and it’s a product of a time that shouldn’t be swept under the rug, just like anything. Neither should DOA but as the medium becomes more sophisticated we have to start making realistic priorities and I really don’t think that involves breast physics at all outside of necessary nude scenes wherever they may be.
If you don’t see them, you don’t need physics for them. If they don’t move, just tell yourself she has a great bra, one that your years of research into boob jiggle hasn’t seen. If it’s for pure fun them let the modding community deal with it; it still gets in there, will likely be more creative and hilarious and you aren’t promoting stupidity in resources with your studio. We can have fantasies and some cool indulgences of course but I’m speaking in a general mainstream sense because the fact that anyone would look at any mainstream game and believe Dragon Age would be improved by jiggling boobs then oh god, you’re lost. There’s story, complex gameplay, visuals and challenge here accompanied by a unique sonic experience directed at and by you. If you even have a second for digital breasts then what are you doing playing a game? Go whack off to porn (with real life jiggle), it’s healthier.
Suggestion: take the old boob physics, put it on butts. Hilarious.
Dude your post is like all over the place I can’t even tell if you’re serious or not.
I looooove the breast physics in Thomas Was Alone.
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