Monday, August 8, 2011

A Matter of Proportion

 This article is intended as a guide to better understand the Second Life avatar mesh and appearance editor, as well as how the broader principles of human anatomy apply in achieving desired body types and appearances.

A Matter of Proportion
How better understanding of human proportions and the Second Life appearance editor can help users create better avatars.

 It is impossible not to think of the avatar when you think of Second Life. The avatar is the very face of the virtual world and the basis around which all content in Second Life is created.

 Despite this, the avatar creation process is probably the least understood aspect of content creation in Second Life.

 The appearance editor itself is a part of the problem. Nine pages of abstract sliders with seemingly arbitrary 0-100 settings for each aspect of the body shape. A remarkable amount of freedom is handed to the user, however the default shapes provided are poorly made and there are no guides or tools built into the appearance editor to help the average user, someone with little to no understanding of body proportions, create a believable, let alone attractive, shape.

 Given just how bad the proportions of the starter shapes are, users who do want a good shape are forced to remake the avatar one slider at a time. Since few SL users are actually professional designers with the understanding of human proportions the appearance editor demands, most are left frustrated and entirely convinced that the avatar mesh and appearance editor are more limited than they actually are.

Human Proportions

 To get the most out of the SL appearance editor, one really does need to have at least a basic artist's understanding of the human shape.

 The Roman architect Vitruvius wrote about his observations of the human body about 2,000 years ago. Leonardo da Vinci improved upon man's understanding of the human body around 1487. Most people are at least passingly familiar with his sketch "Vitruvian Man".

 This wasn't just a random doodle of a naked guy, but a scientific study of the human form based on the writings of Vitruvius and Leonardo's own observations.

 While no one would suggest human bodies are all identical in proportion, there are certain average proportions one can expect any given human body to more or less conform to. Leonardo's image is sometimes referred to as the "Canon of Proportion", reflecting the average adult human proportions. Over the centuries artists and scientists alike have remained fairly consistent with this understanding.

 The average North American/Western European man is about 5'10" or 178cm tall.

 If you take the height of the average man's head and use it as a unit of measurement against his height you will find that the average man is about 7.5 head units tall with the centre of his  height being just above where his legs meet his groin so that his legs make up just shy of half his overall height.

 Stretching his arms out to either side, the average man's "wingspan" will be more or less equal to his height. With his arms at his sides, the average man's fingertips will reach just past mid-thigh.

 Keeping his arms at his sides, we see that the average man is about two head units wide at the outside of his shoulders. Thinner at the hips, which are about as wide as where his shoulders meet his torso, allowing his arms to hang straight down.

 A couple of other helpful proportion tips to keep in mind, the average man's hands are about the size of his face. The measurement from the base of his palm to the end of his longest finger being equal to the measurement from the base of his chin to halfway between his eyebrows and hair line. The average man's feet are about as long as his forearms measured from the wrist to the elbow.

 Of course, it bears repeating  that bodies rarely adhere strictly to these proportions. These merely represent the average adult proportions. Understanding them is key to using proportions to achieve specific body types.

 The above image illustrates a few examples of commonly accepted proportions used in distinct body types.

 "Idealistic" of course, represents the common vision of the "ideal" adult male body. It's still believable but presents the most idealized proportions based on what is commonly considered attractive. The "ideal" man is taller and since our heads don't grow all that much as we get taller he winds up a full 8 heads tall. He is 2 and 1/3 head units wide at the chest, emphasizing a strong upper body.

 Our "ideal" man here would likely be a couple of inches over 6' tall.

 From there the chart moves on to the unrealistic, yet artistically accepted, realms of fashion illustrations and heroic depictions. "Heroic" would be the statues of Greek Gods or contemporary depictions of many modern day super heroes. Usually the more musclebound sort.

 For instance, Superman would likely be depicted as a "Heroic" body type. Spider-Man, on the other hand, would more likely be depicted as an athletic yet wiry "Average". The X-Men's Wolverine would be an oddball on this chart. Short, yet burly, at only 5'3"/160cm but with broad shoulders and emphasized arms like "Heroic".

 You can see from this line up that head size is used to emphasize height and muscle mass. If we re-sized all of these figures to be the same height and broke the image up so you didn't have a direct side-by-side comparison then you would still get the impression that the "Heroic" figure was much taller than our "Average" or "Ideal" figures.

 The wider torso emphasizes the upper body further adding to the sense of muscle mass and strength. You can emphasize upper body strength even more by shortening the legs slightly, relative to the torso, and lengthening the arms. Push that too far, however, and you wind up with a very "cartoonish" or ape-like figure.

Team Fortress 2's "Heavy Weapons Guy" is a good example of these principles taken to a deliberately cartoonish extreme.

 Women's proportions are very similar to men's in terms of head size, arm length, et cetera. Women are generally 7-8 heads tall, 2 heads wide at the shoulders. They generally have a wingspan more or less the same as their height and legs that make up half their height. The primary differences are in the chest, waist and hips, with more subtle differences adding up to a distinctly female form.

 Whereas men tend to have their upper body and muscles emphasized for attractiveness it is more common to emphasize the hips, legs and bust on women. For example, where you might lengthen the arms on a male shape to give him a stronger look you would instead lengthen the legs on a woman to make her more attractive. Only a few inches, mind you. Push the legs too long and you wind up with a stork-like figure.

 Head size is another area where male and female shapes can differ for effect. You don't necessarily want to emphasize a muscular upper body if you're going for a cute or sultry look. Making the head larger, until the figure is 6.5-7 heads tall, can result in a smaller, "cuter" look. Slender shoulder are also often appealing in female shapes.

 With the body, an "hourglass" figure is the classic ideal of beauty. This is most often accomplished with a thin waist and slightly exaggerated hips and bust of about equal width. Some confuse this with the shoulders, when in fact, on women as well as men the shoulders should be wider than the hips, allowing the arms to hang straight down.. Wider hips result in a "pear-like" shape.

 Proportions also change over age, as demonstrated in this image.

Note that these are "idealized" proportions, rather than "average".
 Of course, that is all a very simplified version of proportions, but it should do for anyone trying to make a decent shape in Second Life.

 The Appearance Editor

 Of course, one also needs to understand the Appearance Editor itself. It's not as simple as one would think it should be.

 The first sign that things are not as they should is that the height displayed in the appearance editor is incorrect. It is short by about half a foot ( 15-16cm ) or more. Meaning, if the appearance editor gives your height as 6'/183cm then you are actually closer to 6'6"/198cm.

 This is mainly true of Linden Lab's official viewers, most third party viewers (such as Phoenic, Imprudence and others) display correct avatar height. Linden Lab acknowledged this bug at the release of Viewer 2.1 however, as of this writing and the release of 2.8, the bug has yet to be corrected.

 One often asked question is "what do the sliders represent in terms of real world measurements?" In other words, how tall would a given number, say 50, be on the Height Slider? The answer is that the sliders are entirely abstract, the numbers do not equate to any sort of real world measurements. Nor could they, as the proportions adjusted by any given slider may also be affected by several other sliders. For instance, no less than eight sliders affect an avatar's height.

 This ties in with the misconception that a setting of 50 on any of the shape sliders is the default, unaltered model shape, that if you set all the sliders to 50 that would be the original, unaltered avatar model mesh SL uses, a shape people believe represents "Average".

 That is a very reasonable assumption, however it is entirely incorrect. This is what you get when all of the sliders are set to 50.

 Not the average human body, certainly not the mesh model in its original, unaltered state.

 It gets worse.

 Some appearance editor sliders are also inconsistent between genders. Setting the arm length slider to 70 on the male avatar mesh will get you substantially longer arms than the same setting applied to the female mesh.

 The difference is so substantial, in fact, that it is literally impossible to make proportional female arms for some body types, especially taller women. The taller your avatar is, the more difficult it is to make the arms correctly proportional. Go past about 6'/183cm and it becomes pretty much impossible. This is made worse by the fact that Linden Lab starts women off with avatars over 6' tall.

 The same issue is observable with leg length, except reversed and to a lesser degree. You will have no difficulty making proportionately long legs for either gender, but the sliders are skewed towards longer legs for women.

 There are other bugs as well, such as the broken torso muscle slider for the female avatar. The torso muscle slider for women will change the muscle mass from 0-50, but it has no effect from 50-100. The only work-around is to save the shape as male, re-enter the appearance editor to adjust the muscles on the male shape, then change back to female and save it.

 This bug was reported over a year ago. Many third party viewers do not have this problem.

 Another common misconception is that all one needs to do to scale their avatar larger or smaller is adjust the height slider. This is incorrect as thje height slider does not "scale" your overall body up and down, it squashes and stretches. Meaning, once you adjust the height slider you need to adjust all your other proportions to match your new size.

Avatar Size

 Let's take a look at avatar size and height.

 As mentioned earlier, eight sliders affect avatar height.

Head Size
Neck Length
Hip Length
Leg Length

 Torso Length also affects your height, but not in the same way as the others. As you adjust torso length the length of your avatar's legs will increase or decrease to keep you at about your same height. However, as you lengthen the torso the avatar legs will shrink slightly more, possibly leaving you shorter by a very small amount. A matter of centimetres.

 In addition, Heel Height and Platform Height in the mesh shoe sliders can be used to increase your overall height.

 We've covered that the slider numbers do not represent any sort of relation to average proportions, that the appearance editor displays incorrect height and that no fewer than seven sliders affect your overall height.

 So just how do we know how large our avatar shape is?

 The easiest way is to simply add 6 inches ( 15-16 centimetres ) to the height displayed in the appearance editor. So if it says that you are 6' even, then you are actually about 6'6". This, of course, won't be exact, but it will be close enough for a general idea.

 Alternatively, there are scripted height detectors that were made specifically to compensate for Second Life's misreported height. These are also inexact, but good to within a few centimetres. To know if a given height detector is compensating or not check to see if it matches the height in LL's appearance editor. If it is about 6 inches shorter, then it is good.

 If you are working on a shape that includes prim parts to make yourself seem larger (like furries, robots, werewolves and such) remember that no scripted or client based height detection will take prims or animation hacks into account, so the only way to get your accurate height is the following.

 The only certain way to get your avatar's exact height is by using a pose stand and stretching a prim from the bottom of your avatar's feet to the top of your avatar's skull. All Second Life prims are measured in metres. Prim measurements also match land measurements. If you are unfamiliar with metric measurements here is a link to an online conversion calculator.

 So just how short/tall can an avatar be?

 That depends on whether you are using the male or female shape. Linden Lab made male shapes capable of being larger. The tallest you can possibly be with the male shape, using only the avatar mesh itself, is 8'10"/2.61m tall. To get this tall you need to make use of the mesh "shoe" sliders as well as the base body sliders. Without the shoe options you can still get the male avatar height to an impressive 8'3"/2.54m tall.

 The female shape can be made as tall as 8'6"/2.61m, or 8'2"/2.44m tall without the shoe sliders.

 To put that in perspective, the tallest living man today, as of this writing, is a Turkish man named Sultan Kösen who stands at only 8'3"/2.51m tall. The average NBA basketball player is diminutive 6'7"/2.01m and the average North American man is a miniscule 5'9"/1.75m or 5'10"/1.78m depending on the source.

 At the opposite end of the scale the smallest shape I have made while retaining adult proportions has been about 4'11"/1.50m tall, although you can go shorter still discarding adult proportions. I would actually encourage content creators to create such shapes for attachment building. The smaller you create attachments, the more avatars they will fit. (It's far easier to scale up an attachment than scale one down, due to minimum prim sizes.)

 At the extreme smallest end, without any hacks, you can squeeze an avatar down to at least 4'1"/1.26m tall. About the size of a 9 year old boy, but lacking proper 9 year old proportions.

This is the shortest avatar shape I've managed. All shorter avatars
I've seen were made with hacked viewers and animation tricks.
 About the youngest it would seem you could manage while maintaining correct proportions and average height would be about 11 years old.

Creating A Shape

 With a basic understanding of human proportions and the quirks/bugs of the appearance editor, it is possible to create decent shapes in Second Life.

 You will need only two things to get started.

1. A small piece of land where you have rez rights and prims available. A sandbox will work nicely.

2. A pose stand with a classic "t-pose" and an "arms at sides" pose. If your pose stand does not have an "arms at sides" pose, an "arms straight forward" pose will work almost as well.

Arms straight forward, "t-pose", arms at sides.

 You can get a pose stand free off the SL marketplace.

 Next you will want to press ctrl+p to open the Second Life Preferences panel. Go to the "Move and View" tab then look for "Automatic position for:" and uncheck the box next to "Appearance". This will allow you to enter and exit the appearance editor without being kicked off of your pose stand.

 Before you get to shape making, remove all attachments. Especially shoes and hair (unless prim body parts are a part of the shape you intend to create), also remove any shoe clothing layers (unless the shoe layers are being used as a part of your base body shape).

 The first thing you will want to do is determine the desired size of your avatar. For a plethora of reasons I would recommend aiming for a believable size unless your avatar is something deliberately larger or smaller than a human, such as a minotaur or a dwarven warrior.

 The best way to do this is to decide the height you would like your avatar to be, convert it to metric and create a prim that size to use as a guide. Position the prim next to your avatar and scale your avatar down using the height, neck length and leg length sliders until your avatar is about the height of the prim.

 At this point you do not need to be exact, as your height will be fluctuating as you edit proportions.

Second, you want to adjust your head size. Rez a cube and set the transparency to 50%, then place the prim over your head. Stretch the prim until it is the same height as your head, from the bottom of your chin to the top of your skull. Copy the side to the rest of the cube's dimensions. That represents "1 head unit".

 Copy the prim down until the last one reaches past your feet then count the number of prims. That is how many heads tall your shape currently is.

 As the SL starter avatars and default shapes tend to have abnormally small heads you may need to increase your head size and repeat this process several times until you achieve a head to body ratio you are happy with. The taller your avatar is the smaller your head should be relative to your body.

 A 6' tall adult would be about 7.5 to 8 heads tall. A 6'3"-6'4" tall person may be between 8 and 8.5 heads tall. A 5' tall adult might be closer to 6.5 to 7 heads tall.

 Remember, you have more proportions that need adjusting yet, so if your head size has you around the desired 7.5-8 heads tall range yet still looks too small that may change as you adjust torso and shoulders.

 First, however, we move our attention to the leg to upper body ratio. The middle of your avatar's crotch should be about the middle point in your body if you are aiming for "ideal" proportions. Copy your height cube from earlier and stretch the top down to the bottom of your avatar's crotch then tint it green. Copy the prim upwards until it is end to end with the first, tint this second prim orange.

The prims in this image are actually even with the base of the feet and the top of the skull. Perspective plays tricks.

 For idealistic shapes, leg length should be about equal to the upper body length, meaning the top of the orange prim should rest about even with the top of your avatar's skull. You can shorten the legs slightly, by up to a few inches, to get a more muscled look that emphasizes the upper body.

 Women can achieve a "long legged" look by increasing the leg length by a couple of inches. It doesn't seem like much, but a combination of such small changes in proportion can completely alter perception of a figure.

 Also keep in mind that you have three sliders to adjust at this point. The leg length slider, torso length slider and neck length slider. Remember all three sliders affect your height, but the torso slider affects it the least, meaning less adjusting og head size later if most of your adjustments are with the torso slider. Just try to avoid a squashed/stretched torso look.

 With that taken care of we'll want to take a moment to check height and head ratio again. Make sure you're still about the height you are aiming for and the proper number of heads high for your desired body type. Since you should not be off too much you can probably make small adjustments to the height slider to get back to where you'd like to be. Otherwise adjust head size and re-check the head to body ratio.

 Now we move on to the upper body proportions.

As you can see, this shape is slightly wider than 2 heads at the shoulders.

 You'll want a good "arms at sides" pose, lacking that a pose with your arms straight forward. Measuring your torso width to the outside of your upper arms you should be about two head units wide. If you are going for a muscled, burly look you may want to be slightly wider than 2 head units. The "Heroic" shape in our figure lineup is 2 and 2/3 heads wide.

For a more slender look you can narrow the width here slightly. Be careful, too much and you will wind up looking more child-like or pear shaped if your avatar has wide hips.

 You have the Shoulder Width, Body Thickness, Body Fat and Torso Muscle sliders at your disposal to balance out a good torso width.

 Next we take a look at our avatar's hands.

 The average adult's hand is roughly the size of their face. That is, measuring from the bottom of the chin to about halfway between the eyebrows and hairline should equal the measurement from the base of the palm to the tip of the longest finger.

 Some men may like to go slightly larger for that "big, strong hands" look, but too much and it will look cartoonish.

 Once the hands are a good size we move on to the wingspan, which is the measurement of your arms stretched out to either side. The measurement of your wingspan relative to your height is known as the "ape index". The "ideal" adult shape has a wingspan that is equal to their height.

 We can measure this on our avatar by taking the prim we used to measure our avatar's current height, centering it with the body of our avatar and flipping it on its side.

 Keep in mind that the avatar bends the shoulders in an odd way, squishing them into the avatar torso slightly. You can account for this by making your wingspan an inch or two shorter on each end than the height prim. Extend all the way to the prim for slightly exaggerated arms.

 Overly muscular men may wish to make their arms slightly longer to emphasize upper body strength. Remember that making the arms too long results in an ape-like or cartoonish look. Short arms are generally considered unattractive so you want to be sure that your arms are at least within a couple of inches of your height.

 Once we're satisfied that our avatar's arms are the proper length we can check our feet. The "ideal" adult's foot will be as long as their forearm, measured from the wrist to the elbow.

 As you finalize your shape here are some more tips and reminders.

 Your hips are not as wide as the outside of your shoulders. Where the "ideal" adult shape is 2 heads wide at the outside of their shoulders they are only 1 and 1/2 heads wide at the hip. Women's hips are accentuated by a thin waist. The "ideal" woman shape is 1 head unite wide at the waist.

 Breasts, belly, bodyfat and other shape attributes tend to distort when pushed to either extreme. Try to find a good balance.

 Even the "ideal" body shape should have a bit of bodyfat. As a practical issue, body fat of zero increases unnatural looking sharp edges on the avatar shape.

 If you are not well versed in human proportion and anatomy then search the web for figure drawing and other proportion guides that may help you with aspects such as facial features and achieving specific body types.

Improving the Avatar Creation Process

The Second Life Appearance Editor is in dire need of an overhaul, but here are a few ideas Linden Lab could possibly implement to make the avatar creation process easier and more fun for users of all skill levels.

Most videogames avoid Second Life's avatar creation issues in two ways.

 First, they limit the user's ability to adjust the body shape.

 In some games and virtual worlds you are only able to adjust facial features. "Oblivion" and the more recent "Fallout" games are examples of games which only allowed players to alter the head, face and skin tone of their character. Attributes like body shape and height are locked. The virtual world "Blue Mars" took a similar approach, locking all avatars to the same height.

The character creation screen from "Fallout 3".

 Second, and better for Second Life, they provide "template shapes" for people to start from.

"Champions Online" and "City of Heroes" are perfect examples of this. During the character creation process you choose from one of several body types (such as slim, athletic, muscular, huge) and then customize your shape from the basic template provided. You can still go well outside normal human proportions, but the templates nudge players in the direction they want to go, making it easier for them to create shapes they are happy with.

 Of course, Second Life is not typical of videogames. It has no burdens of gameplay mechanics requiring specific avatar sizes and SL's content creation benefits greatly from the exceptional amount of freedom allotted to avatar creators. It would be a mistake to place restrictions on avatar creation similar to the restrictions found in "Fallout" and "Blue Mars".

 Still, with the amount of freedom granted to Second Life users it is necessary for Linden Lab to provide certain tools and guides so that one need not be a professional artist just to achieve results similar to what the user holds in their mind's eye.

 Rather than hard proportion limits, Linden Lab could provide an optiona "Proportion Lock" which could be toggled on and off at the user's discretion. This would help those who desire human proportions stay within those limits without placing restrictions on those who desire the full range of possibilities currently afforded by the SL appearance editor.

 When checking an avatar's proportions it is important to be able to see the avatar in multiple poses. The "t-pose" and "standing straight, arms at sides" pose are both universal proportion checking poses that the Second Life appearance editor lacks. To check your avatar in any pose other than default "appearance editing" pose LL provides requires fiddling with the Preferences and tracking down a user created pose stand with some good proportion checking poses.

 Visible proportion guidelines and silhouettes would help immensely. Even the professionals do not work without the aid of guides. The appearance editor could be made to display head units automatically without the need to mess with prims, along with silhouettes of example shapes or guidelines displaying proper arm length relative to your height.

 Finally, and perhaps most importantly, template shapes could be provided to new users both through the Library and within the Appearance Editor itself as options when creating a new shape. Such templates would need to be professional quality, with correct scale and proportions. SL's current human starter avatars and default shapes are all over-sized, suffer from poor body proportions and are generally unattractive.

 It is much easier to create a tall thin supermodel or a short and stout dwarven warrior if you have access to body type templates that provide you a good basis to start from, rather than being forced to create the shape one slider at a time from a poorly made default of the entirely wrong body type.

 Hopefully as Linden Lab seeks to make Second Life "fast, easy and fun", ideas such as these will be among those they consider for improving the avatar creation process.


  1. FYI, I've mentioned your excellent blogs on my blog :)

  2. Hee, thanks for the mention!

    Everyone should check out 1920's Berlin when they are able, it's one of the few great examples of just how much more you can get out of SL when you build to a reasonable scale instead of being forced to compensate for exceptionally large avatar sizes and bad camera placement.

  3. Great article, Penny. May I add a couple of pointers to some free shapes available on the SL Marketplace? These are based on the Vitruvian figure.

  4. Thanks Brenda! Those are shapes I created some time after writing this article. I intend to do a couple follow-up articles in the near future explaining how to achieve different body types by using proportion and plan to link to those as good starting points. After all, it's far easier to create a good shape when you start from a good shape. That's a part of why LL's starter avatars are so problematic. They make it more difficult for SL users to create good shapes when they start from shapes provided with the starter avatars.

  5. Well I found this article about 3 years too Excellent info even for RL. I'm sure my hands are not

  6. Firstly, thank you so much for this, I've been sharing it around SL as much as I can. There is one tiny detail I'm a little confused about though, in the article you say "The very bottom of your avatar's crotch should be about the middle point in your body if you are aiming for 'ideal' proportions" but according to the diagrams, if I'm not mistaken, the actual ideal midpoint is slightly above the bottom of the crotch, is it not? I'm not artist, so maybe I'm reading it wrong, but that's how I understand it...

    Either way, thanks. For this and all your other "A Matter of" articles.

    1. No, you're right. Not sure why I wrote the bottom of the crotch.

      Anyways, thanks for pointing it out, I've corrected the wording in the paragraph.

      I'm glad the articles help! I want to eventually sit down and write up some more. I've got a lot of things to say about the use of sound, lighting, and plenty of general content creator tips I'd love to share. I'm just so busy outside of SL these days it's difficult to find the time!

  7. Penny, I blew a whole morning playing with this! All kinds of boxes were made and posing stands located, etc.

    If everyone wasn't so tall it would work well, keeping that in mind, I sort of chose a balance between the Idealistic and the Fashion, otherwise the Idealistic is Munchkin for most of my SL experience. Wonderful fun and a very lucid explanation, well done!

  8. Excellents conseils pour tous les utilisateurs de Second Life. Ce blog est encore bien utile en 2015. Merci !

  9. It's 2020 and this is still relevant.