Bird's wings

[eek]

I might have some time to look into this next week - I've been fasinated by how birds wings work for years. Essentially you have to treat it like a humans arm:


The ability to extend
The ability to twist about the shoulder and wrist
The ability to 'fold-up', due to the tendon.

Birds wngs are very much like our own arms, so I'd first advist making a arm rig that can do all the things we normally can, namely extend, and twist - the twist about the shoulder and wrist is crucial.

Secondly is the ability for the wing to 'fold-up' this from preliminary research is due to a tendon, which runs all the way along the arm (like a chain) with the feathers going through it attached to the muscle.

This allows them to twist, for banking, turning but also to fold-up. Basically up until the hand bone the feathers roughly stay 90 degrees perpendicular, to the vector the arm swivels about. I'll explain with a pic:

[PEN]

I'll see if I can find the one that I did for a recent client and post it for you to look at as well.

[xenoid]

Very nice explanation eek. Thanks for sharing.

[scrimski]

I'll see if I can find the one that I did for a recent client and post it for you to look at as well.

Would like to see it too.

PEN, how's it going with the mechanical rigging DVDs? Any news?

[TTYO]

Hey I just got a new development on my bird rigging...

http://www.freewebtown.com/embryo/new%20wing.avi

[PEN]

Here is a test of it that was done.

http://paulneale.com/temp/wingTest.mov
http://paulneale.com/temp/wingRig.jpg

Gave the animators lots of control and some built in dynamics for the feathers that was vert fast to calculate.

[scrimski]

some built in dynamics for the feathers
What kind of? Flex?

[PEN]

Ya, flex is running on a spline. That drives all the feathers.

[shalabology]

hey there very interesting topic , paul very nice to hear from you here but the video doesnt declare much-for me at least -about techniques used in that rig xcept wat u said ,more details if you please?

[PEN]

It is hard to describe what is going on in there. Each feather has a bend and wave modifier on it. The bend is controlled by lookats that are looking at the spline. The wave is controlled by the animator for shaping a cup in the wing. There is the wire frame with all the point helpers showing.

http://paulneale.com/temp/wingRigWire.jpg

[PEN]

Flex will allow you to add wind so you can get an effect like this for free.

http://paulneale.com/temp/wingtest02.mov

[xenoid]

Very cool setup you have there Paul. Thanks for sharing.

[monkey-sage]

I rigged a hawk for a flight animation recently and realized that with the mesh that I had created didn't leave enough overlapping to have a good fold motion. The best rig that I made had three different sections for the feathers so that when extented they all lined up, but when the wing folded back they would fold under each other (using creative constraints).

I like Pen's solution... it's pretty.

[bin23]

Pen, can you talk about how you used the bend modifier on the feathers. How were they wired? If you don't mine me asking.

It sounds like there are no other bones, but the three in the arm and instead of the lookats working directly on the feathers as constraints they are used to calculate the angle the bend modifier will be applying to each feather.

Thanks a bunch as always.


Bin

[PEN]

Correct, just the bones in the main wing and the rest was driven with a few modifiers. I had a bend and a taper (I think) on each feather that I set up with Max script. The bend was wired to the dynamic curve that was driven with flex. What it did was look at the curve basicly but used the bend angle. To know if it was to bend up or down I used expose transform helpers and compared the postion of a point along the curve with a point parented to one of the bones in the wing. I then knew if the feathers should be bending up or down. There is also full manual control as well as the dynamic curve is control also be control objects. To Cup the wing I used the taper modifier and worked with the curve amount (I think, would have to go back and have a look at it), this was script controllered to the controls so that each feather could have multiple inputs from the controls.

Here is the page that I put together on this http://www.paulneale.com/technical/bellaSara/bellaSara.htm

[bin23]

Pen,
this was really helpful.
At the moment, my feathers are wired directly to the z-position of a SplineIK, control helper, object. It a bit clumsy.

At any rate, I was headed in the direction of building states and using the Reaction manger. I've found this to be a sluggish and costly answer. Your BellaSara wing rig seems an elegant and economic solution. I hope to stay in that direction for my own rig.


Thanks Again,

Bin

Well still plugging away at the rig. If you have the time to look at your old rig or remember how you attached the feathers that would be a great help.

Bin

[PEN]

I have uploaded a demo of me using the rig. have a look at the bottom of the page. More will come as I'm just rendering some new movies as well for it.

[bin23]

Pen,
thank you for posting this demo on your site. I really appreciate you taking the time to do this: sharing your knowledge, recording this video. This is quite a gesture and I hope it finds a place on your fifth DVD; I'd certainly be interested in purchasing that as well.

Bin

[PEN]

Your welcome.

[Polimeno]

woow,
cool rig Paul !! nice done, congrats !

i don´t understand the part that you say about the custom attributes, "bias" and "wave" for each feather and how does it react with the controls....

and please, if possible, show us some screens of "under the hood" abot bones, helpers and hidden stufs.

=)

[bin23]

Hey RNThead,
I am not certain about this, but the "mult" and "bias" custom attributes look Like they are effecting the amplitude and phase or decay respectively.

The control objects along the green spline, those effecting the feather tips look to have slightly similar though localized functions. These controls almost appear like a falloff of the lookat constraint, but that doesn't seem to be likely.

I was hoping to offer some answers, but I am afraid I may have left you with other questions.

Well, I hope my feable attempt helps.


Thanks again to Pen for providing this.

Bin

[PEN]

Well I don't want to give it all away as I would rather be hired to do the work then to just give it all way for free;)

As for the Multi and Bias, they affect how much each feather is controled by the controls nearest to it. So you can custom control how much each feather is affected. Also you can hand animate the values as well and rotate each feather if need be. Animators can't have to much control.

Glad you like it guys.

[shalabology]

i have been away for a while then i found your explaination for the rig and the new demo videos
really brilliant setup simple but not easy , wat i stilll dont get is the cupping how taper would help in it ?
iam just curious to know it.

[PEN]

I didn't use taper I used a wave modifier.

[shalabology]

oroginally submitted by PEN


To Cup the wing I used the taper modifier and worked with the curve amount (I think, would have to go back and have a look at it),


paul you mentioned it earlier , and i think after revising the demo video again that they are for squeezing the feathers someway in tops when the wing is cupped
again, very interesting set up ,always inspired by you!

[PEN]

My mistake, they are wave modifiers instead. The great thing about having a bad memory is I get to learn new things every day.

[Da_elf]

nothing special but i did this about 4 or so years ago
http://www.elfpro3d.com/Gallery/pelican.mpg

[PEN]

Looks good, why not share how you did it then.

[SuperWoko]

Hi there. Here is Tutorial which I made last year about wing rigging. Youtube (http://pl.youtube.com/watch?v=uvO4B71mFek) and rapidshare (http://rs241l3.rapidshare.com/files/73084010/superwoko_skrzydlo_rigg.avi)

[Da_elf]

it was a while back but i remember having 1 dummy over the shoulder blades that when rotated would fold the wing bones in then aall of the feathers had on a rotation reaction controler i think which when the wing bones were folded in the feathers rotated into the correct orientation. there were other controler dummys which did things like make the wings flap. i also thought to put on flex on the feathers

[TTYO]

Then what about folding the wing?

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