Bones: Flexible vs. Region Binding

[Toontoonz]

I always set the Bone layer on Region binding (as the tutorial states).
When would I want to use Flexible binding for all bones?
Any examples of when Flexible binding is better to use than Region binding or vice-versa?

I assume one cannot have Region and Flexible binding in the same bone layer - why not or why wouldn´t one want this alternative to choose a different binding for a different bone?

[7feet]

The frimary difference between flexi and region binding is that in the flexi binding mode, each of the bones witll affect every point in the drawing to some degree - depending on the bone strength settings and the distance of the point from the bone. Each point is affected by multiple bones to one degreee or another. This can useful for a more generally "squishy" look to your character. In region binding, determined again by bone strength and distance, each point will be controlled exclusively by one bone. This leads to more control and consistency over the movement of your character.

It would probably be kind of useful to be able to be able to assign a flexi or region "type" to a bone, but I don't really know how that would work as far as programming it. Or using it. They're kind of 2 sides of a coin, might be difficult to figure out what influences what. As it stands, the best way to that middle ground is to use flexi binding, but bind the points you want controlled by only one bone manually to that bone. More work as it's not all automatic, but does allow you to use both styles for one skeleton.

[Lost Marble]

In region binding, determined again by bone strength and distance, each point will be controlled exclusively by one bone.

Not quite. In region binding, each point can be controlled by multiple bones - which bones have influence over a given point is determined by which bone regions overlap that point (as shown by the Bone Strength tool). If a point is within the region of just one bone, then only that bone will have influence over it. However, if a point is located where multiple bone regions overlap, all those bones will influence the point.

[7feet]

Sorry, I was unclear in expressing that, if I took a few more seconds checking it out I would have known how to say it before I opened my yap.

[Toontoonz]

Thanks for the replies; however, after reading your replies and the tutorial regarding bones I am having a hard time visualising when one would want Flexible over Regional or vice-versa. One must choose one or the other.

Can anyone give me a visual animation example of when Flexible would be the better bone type choice? A bus driving? A horse jumping? A cloud with one bone? A hand that is regional boned and the arm flexible or ???
Something that has a couple of bones or lots of bones?
I have experimented a bit with both bone types and can´t think of anytime when Flexible boning would be better - even though it is the default setting - because I would always want the better control that Regional boning appears to give.

I guess I have to experiment some more.

[Toontoonz]

Here is a little test I did to compare Flexible vs. Region bones.
It is a green, 4-toed hand or foot. I made the object, added the bones, selected Flexible binding in the Bone layer for the hand on the left.
I then copied it, moved it to the right of the screen, went to the Bone layer and selected Region binding.

The Flexible one seems smoother, more realistic, the Region one creates more edges in a couple of the extreme positions. Other than that I see no real difference.

The link: (500 K Quick Time movie)
http://toontoonz.com/animatests/bones.mov

In the future, I think I may have to try both methods of binding when building the animation.

[Lost Marble]

I don't think anyone will be able to tell you specific situations (like a horse or a hand) that are better for flexible vs. region binding. Flexible binding gives you a more rubbery/squishy kind of look, while region binding gives you more control.

One of the problems with region binding is that you can get those creases that your hand example shows. On the other hand, flexible binding can cause a bone to affect the moement of relatively far-away objects (a toe might move a little bit when an arm bone bends). These are just some tarde-offs you will have to choose between for your own projects.

Flexible binding is the deault setting because it is generally more "automatic". If you draw a quick character and add bones to it, flexible binding will usually make it move around with some reasonable accuracy. Region binding usually requires some more setup (adjusting bone strengths) before it looks OK - that's why it's the non-default option.