OT/General BJD and human joint limits

I've never seen a bjd arm that allows it to be folded completely in half - there's usually an angle that stops it from bending back completely upon itself. As it is, when I tuck my own arm up as far as it'll go, there's -at most- a palm's length from wrist to shoulder. I'd say it's more like 160 - 180 isn't possible as that would assume the stringing channel for one part of the arm actually intersects the stringing channel for the other part - same with legs - probably not going to be able to physically exceed 160 simply because of resin in the way.

Most double-jointed-knee dolls can tuck their legs up underneath them, so that their heels can touch their bums - which is a natural and attainable pose for most (younger) humans with a regular degree of flexibility.

Personally, I think a reasonable compromise between having to do the joints for additional flexibility vs. the possibility of over-flexing is to create stops and locks and little pips in the joints to help prevent them from over-flexing. For example, to stop a double-elbow from over-flexing, there could be a little set of teeth on the double-elbow that locks onto the edge of the forearm when it flexes to the maximum, and would tend to prevent it from flexing further (without popping out of joint). I'll be doing this with the upper-thigh joint on my doll, to prevent the leg from turning itself around.

 

A doll is a doll, and the joint design should be up to the individual doll maker. There are no rules, really. Perhaps the doll maker wishes for the doll to be a gymnast? The joints for such a doll will be designed accordingly, probably with double joints, and hyperextended limbs.

A doll that is going to be posed sitting in the Japanese Tea Ceremony pose, will have joints that allow sitting on the lower legs, such as double jointed knees. I've read that some people think those double-jointed knees make the doll look like some kind of bug, but others love the posability of such a doll. For example, the Thaasa body by Doi Shin (Shiny Doll) has a concave area behind the upper leg, right above the knee, so the calf can fit when the doll is sitting on the floor, Japanese Tea Ceremony style. If I want a doll to pose like that, I will make a Thaasa-style body with that kind of indentation.

However, if I want a doll that is mainly going to be standing, then such a concave indentation might not be the best choice, nor would double knee joints be necessary, especially if the doll was designed as a fashion doll to model mini-skirts?

I like to see the joints in a BJD. No matter how realistically the doll is sculpted, the joints remind me that it is a doll. The choice of whether the doll will have joints that are nice looking, or will be super-posable is up to the doll maker. Resin dolls are made of a rigid material, and I don't think they will ever be able to totally imitate the bones, muscle and skin of humans. I'd rather not experience the 'uncanny valley' when meeting a doll.

Perhaps the life-size sex dolls come the closest to imitating a human? They really don't interest me that much, even though they can be posed like a human, but don't show the joints. I'd much rather have a resin BJD that shows the joints. My $0.02.

 

You asked.

No offense taken.

 

Many humans have joints than can bend farther than the limits you mention. For instance, I can sit with my butt on the ground and my heels tucked beside it. Or the gymnasts who can do a full split. Maybe the variations in BJD flexibility can mirror the variations in humans.

Humans do have the advantage of being squishy, though. BJDs can't do the same thing without notches in the backs of their legs etc. The other place humans have it over BJDs is spine flexibility. Someone else here was trying to figure out a way to make a fully flexible BJD spine. Don't know if they managed it.

 

This Special Fullaction Body Type-1 was recently pointed to by penguu in this thread.

The Japanese doll maker, Hanano, has explored flexible joints for his dolls. This is his weblog. I'm looking at page 30 of his weblog, and thereabouts. The more flexible his dolls become, the more body plates there are, to more or less hide the joints in the body?

Squishy is certainly an important advantage! :XD Resin and porcelain are rigid materials. Ball joints are a ball and socket joint system, and they dictate a certain aesthetic, an aesthetic that forums like DoA strictly adhere to. BJDs are strung with elastic or springs through the joints.

They are not at all like the so called "fully articulated" Barbie(TM) dolls with hinged joints, where the hinge sort of covers the slot when the limb is bent. I think that is a case where having articulated joints that were not as obvious, was used. Action figures also use hinged joints that hide the slots, and I don't think they are strung with elastic (or springs) either.

So in ball-jointed doll making, there is necessarily a compromise between joint aesthetics and flexibility? The more range of motion the doll has, the more the squishy parts on a human will have to be concave on the doll, so another rigid part can fit? Or, the slots will show on joints that are doubled, and so forth?

 

I'm currently sculpting a 60cm doll that's "Like me" (After seeing so many people saying "Why don't dolls represent the full spectrum of human appearance?) My solution to give her the limited mobility needed was to add blocks to her hip and knee joints - Preventing them from flexing further without the joint "opening", and thus springing back to a less-flexed position. Likewise, her hips are oval, rather than ball shaped, stopping them from rotating sideways.

Then again, this is all still just a copper-pipe-and-clay stick figure - She's got no soft tissue yet - so by the time she gets to the detail stage I might get bored and turn her into a contortionist

 

I think you are confused about what being 'reminded that it is a doll' means. It's not normally a distinction between dolls and humans, but rather between dolls and sculptures of humans, or between BJDs and action figures or Barbie dolls. If there is a connection to humans, it's a reminder that BJDs are judged on an extra level of aesthetic, that of jointing. Unlike a sculpture of a human, a BJD incorporates the art of balance and compromise - flexibility will always come at a cost of realism, and the intent of the artist can always be read in the joints they create.

Visible jointing is an aesthetic part of dolls. There are lots of options for people to collect if they want invisible joints, but those are not BJDs. I'd also expect that most BJD artists (as on this forum) would be even more devoted to the aesthetics of jointing, as they know how personal and important the design of them is.

Personally, I prefer hyperflexibility in my dolls, because it allows me the choice of how flexible my doll will appear, rather than the artist. I can limit a dolls poseability through careful posing, but I cannot add to a doll's poseability without having to mod the doll.

I also have much greater flexibility than you claim is the 'maximum range' of humans, so I'd have absolutely no interest in a doll limited that much. If I bought a doll that was so limited, I would immediately take it apart to mod for flexibility. I'd be much more likely to avoid it entirely, to save myself the trouble, though. To me, limited poseability is a 'flaw' in a doll, whether it be due to a poorly skilled artist, or due to intentional meddling on the artist's part.

 

OK, I get what you are asking now. I'd vote for realistic-looking joints, if I had to choose-- but I'd really rather have BOTH realistic joints and hyperflexibility, if that's possible.

I'm thinking of the Iplehouse EID guys. The joints are beautiful and realistic when unflexed, but when flexed some of them are downright ugly.

 

The larger Obitsu dolls are also mechanical afaik, not strung with elastic.

 

I prefer lots of articulation on my dolls and I don't care how the joints look at all as long as they function well. I see this come up a lot in the action figure hobby and I always say if I wanted perfectly smooth seamless figures I'd just buy a statue.

 

I have a doll that with out pulling the joint out and essentially engaging the doubled joint on it it has very much a human limitation of movement. Admittedly in photographs he looks fantastic! I knew that when I got him that to engage more complicated poses, I would have to deal with some ugly joints. Over all I personally find positive aspects of both types, but I would prefer to have mobility over the super realistic joints.

 

I prefer flexibility/posability over aesthetics. I don't even notice any of the joints on my dolls anymore.

 

Agreeing with Kwmelvin, assuming that a doll has more flexible joints, it can play a variety of roles like gymnast or someone young while still being able to play someone who isn't a gymnast. But if it is 'natural' the doll can't pose as a gymnast, right?

 

Personally, I like to see joints, I like to contrast between a realistically sculpted body and those jarring, odd ball joints. So some realism is important to me but I dont need the joints to be in-keeping with the rest of the doll's aesthetic.
I own a double jointed doll and a non double jointed doll and yeah, the double joints do look very odd. I like them both for what they are though. I also like the concave back of thigh solution to leg felxibility but that's not at all realstic-looking.
I guess I want a doll to be reasonably flexible and pose naturally, even if natural isnt the same thing as realistic - I'm just not going to pose them in weird contortions or with hyper-extended joints enough for it to be an issue. Yeah, I can hyper extend my own joints but I have to admit it looks a bit odd, I wouldnt pose my dolls like that, even if it is technically realsitic. My basic requirements of a dolls flexibility are suwaricco sitting, being able to touch their face with their hands (or close to) and kneeling convincingly. Oh and I need at least one torso joint.

 

More like it plays a better role as a model. A large part of the hobby is taking photos so IMO, doublejoints are worth paying attention to to make them attractive :3

The thing I don't get is that I see a lot of dolls which have hands which can't pose very well. It's just dead straight forward sometimes. They can express so much emotion if they're done properly

 

Ideally, I want/prefer for dolls to flex realistically with unobtrusive/aesthetically pleasing joint. I don't really like the look of double joints--they give a weird boxy look when bent. I never really thought about what angle a joints bend at, but if 180 isn't natural, I'll go with what is natural.

For my first big doll sculpting project, I made concaves in the back of the thighs, and a large single ball joint at the knees, so the bend his knees way more than 90 degrees. The sacrifice is the indents in the back of the thighs... I know some art dolls and a few BJD companies do leg joints like this (a few of Dollstown dolls, I know, but I haven't seen them posed).
For my next doll, I just went with simple single joints for aesthetic purposes, but it felt pretty limiting.
So with my third, I'm going with legs like the first, and the arms shaved down a bit so they can bend farther even though they are also single joints. I hope my explanations make sense ^_^;;

My only issue now is the thigh-hip joint-- how can I have it bend more aside from a double joint? I could do an inverted thigh joint, with the ball of it cutting in deeply to the torso so the thigh piece can slide farther... I don't that would be too pretty, though.