Hi Erogenesis, I am late seeing this message thread, so, my comment maybe already covered off.

You asked about extra bones, and suggested the abdomen area. Yes, yes please.

We use Poser & Daz for illustration and training in sport - artistic ones such as Gymnastics and others where body and limb movement at critical stages of a movement, are needed accurately - polevault, high jump etc, showing how the bulk of the body shifts weight around its CoG to achieve movement progression. The points of bend, and shape of back, are critical

We have great problems getting figures to bend correctly because they are missing pivot points in a bend from hip to neck. Now, if you could put one for each vertebrae, or each pair, we would really have something behaving naturally.

And that would then allow a more natural twist in the torso, especially a twist and bend. Our problems with bending and twist are greater when we animate these movements. While we can stretch and shrink skin/flesh to make a still pose bend/twist look right, that's a huge amount of work in an animation to get it looking good. And, we want realism, othewise its little more than using stickmen and puppet figures.

For athletes viewing it, we can't mask the skin/body movements with clothes, they need to see it with the figures wearing what they do - that gives a lot of bare torso skin, or skin hugging leotards which are more or less skin, to model. Now with photo-realistic skin mapping making figures look so life-like and fascinating to the end-user, its devalued by unnatural skin movement in the torso.

Yes, we can put the work into getting skin meshes to do what we need. That's workable for a one-off. But then we get asked to make ammended movements, which makes a lot of work for something that should be relatively easy.

We also use the poses in medical process illustrations. We have to morph (its more of a merge) in bone structures and organs. Take for example when we illustrate CPR resuscitation showing the ribcage and chest cavity being depressed by 2" - 40 to 50 times a minute. For realism the back will bend as the sternum (approx centre chest) and ribcage is pressed, the abdomen will be pulled, and the neck will bend, each time the chest is depressed. As the head will be twisted to one side, getting it to then bend up and down relative to the chest, rather than the angle of the head, is currently a problem.

The minimal pivot points from hip to head make it so difficult, we have to use a series on still pose animations of every 200th frame in an animation. If we let the programme in-fill between these frame points, we get odd skin twitches and oddities occuring. Rectifying these causes a twitch in a diffrent place. V4/M4 or later figures, its the same.

Of course, some will say we should be using more professional programmes, MAYA and so-on. It's a cost/income balance.

Any thoughts there re your figure ???? A solution would be really exciting. PM if you wish to.