Wing

Feather Rigging

Poly feathers driven by hair on dynamic joint chains. Seems to work well for

secondary motion. (Ryan O'Phelan)

Bird Body

Bird Neck

http://www.penproductions.ca/technical/bellaSara/bellaSara.htm

Neat trick from Brad F.'s old bird rig: quick cheap way to curl a lot of joints at once--just connect the rotate of joint B to rotate of joint A, which is driven by controller.

http://www.jackals-forge.com/tutor/tut2.html

Feather Ruffling

saw this thread and I thought I would try to explain how I did this effect in the past.

I have rigged a few birds and one bird dragon.

The first bird I rigged was a Crow for Warcraft III. It is the crow that flies into the shot and lands in the throne room (towards the start of my reel). Originally there were two rigs, after I re-rigged the character the animators were able to open and close the wings so that the Crow could fly in and fold up his wings.

When I worked at Blur Studio I did a couple more "feathered" characters. The first was bird dragon. You can also see it on my reel between 1:18 and 1:20. On a side note this was done in Max 5 with 10,000 feathers. Talk about painful. I also did a Hawk for an Everquest Commercial.

All the rigs worked the same way (although the Bird Dragon had to have a lot more control over its' ruffling) individual modeled feathers being driven by an underlying mesh. The Blizzard Crow had modeled feathers for the wings and tail. The Blur Bird Dragon and Hawk had modeled feathers for the entire body.

In all three cases I used biped for the rigs. The exception was that the Bird Dragon had a biped body and a custom rig for the neck, wings and tail. I also did a rig at LLP for a giant crow that was all custom rigged.

What I did was try to mimic how the feathers are on a real bird. I started with the model that was handed off to me. I rigged the body as you normally would, but for the wings I tried to keep in mind how they would fold. Knowing that the geometry would be driving the feathers. That is a little hard to explain but I am going to try...

The first Crow I did at Blizzard took a LOT of trial and error until I finally figured it out. I think I had to re-rig the wings four or five times until they would fold correctly without the feathers sticking out in all directions.

I took the feathers and did a reset xform on them (so that the z axis was pointing up). Then I created a point attached to the surface of the wing then linked the feather to that point. Depending where and how the point was attached, when you folded up the wings the feathers would follow the surface and "fold" up. Again, I was trying to mimic how a real bird would fold its' wings.

I now have a script on my site that does all the attaching for me. It is called Attach_To_Surface_by_Local_Z it shoots a ray from the Z axis of the selected objects to a target mesh then creates a point on the surface at that location and attaches it to the surface. Finally it will link the object to its' point on the surface of the target.

Having the feathers attached to the surface of the bird made it easy to control how they would fold and spread. Look at it this way...

In the top view, Create a long box with 10 or so segments in it. Have the long axis go in the x direction. Then create 5 more boxes that start at the first box and have the long axis of these boxes pointing in the -y axis. Create a point for each box where it meets the original box. Then attach those points using an attachment controller. Link the small boxes to each of the points you created for those boxes.

Now put a bend modifier on the original box and try bending it in different directions. Try moving the center of the bend and see what happens. This will BASICALLY show you how the undelying mesh can drive the feathers in a full rig.

(It is real late but I can try to create some samples tomorrow and attach them to this post).

Just so you know, most of the work is actually spent in the deformation of the bird than dealing with the feathers. You need to be sure that the mesh is deforming cleanly. Otherwise, a pinch will be exaggerated by the feathers.

Now, to handle the ruffling, all I would do is use a displace modifier using a noise map on the mesh that was driving the feathers. The higher the displacement the more the feathers would ruffle. The faster the noise the quicker the feathers would ruffle. Real simple.

I hope that this can at least get this discussion moving. I realize that I may be over simplifing this but I am willing to answer any questions you may have.

-Paul

p.s. As a side note, I am working on a training DVD that would take you through the entire process of rigging abird with feathers (and a dragon as well - no feathers).

__________________

Paul Hormis

HYPER|bolic Enterprises, Inc.

John O'Connell

Make a really heavily colour corrected version of the feather texture so that the bright areas of the texture are white and all of the fine lines in between the hairs of the feather are black. You can make this differ depending on the angle to the camera by using a mask map. Put the black and white feather map into the mask slot and a falloff map into the map slot - if should give you some nice variations in the shininess.

Also another method for the ruffling that I saw was to use a look at constraint on each of the feather bones pointing at a null that was constrained to the wing bones - you can put a noise controller on the null so that the feather look at is jittering around giving the ruffling effect - I think I preferred the look of it a bit better since it looks like the root of the feather is still tightly anchored to the wing and gradualyl falls off into a nice wind effect at the tip.

For ruffling of the feathers, if I wanted to make these babies fly, I've put a noise controller on the rigging mesh for just this purpose. For all other feather movements, I've rigged 4 layers of bend controllers, which each feather has 3 bend controllers, one for the lift, curve lengthwise, and curve horizontally. Because the vertical bend controllers are wired to a series of sliders, it makes it easy to "fluff" the down feathers, and then the other layer 75%, etc. I guess I could wire these to one controller that has the expression built in. We'll see if I need it when it's time for finalizing the animation & final rendering.

martin bird: http://forums.cgsociety.org/showthread.php?threadid=41699

folding wing: http://www.xsibase.com/forum/index.php?board=11;action=display;threadid=28727

simple fold: http://forums.cgsociety.org/showthread.php?f=54&t=827889&highlight=bird+rig

Resources

Bio Animation- Wing Spread and Fold - squidlifecrisis

https://www.youtube.com/watch?v=GFCgwglikcY

Nak Young Kim - Wing Rig Demo

How Wings Work

Great Flight Ref by Brendan Body

Bird Wing Anatomy: http://fc08.deviantart.net/fs10/f/2006/078/8/b/brrdtut.jpg

- owl attacking camera, flying straight at it: http://www.youtube.com/watch?v=LA6XSrM0V_0

- nice (un-)folding owl wings: http://www.youtube.com/watch?v=yVQVdGaAu6s

- eagle riding on the wind and landing: http://www.youtube.com/watch?v=ytViF4OcxHk&feature=related

- eagle catching prey: http://www.youtube.com/watch?v=tgRN08CA8-w&NR=1

- seagulls from various angles: http://www.youtube.com/watch?v=tIbRQpANt0c

- hovering hummingbird: http://www.youtube.com/watch?v=OYVtdZdiD9k

- pelican diving for fish: http://www.youtube.com/watch?v=cB2UZpmYPuU

(Marco de Goeij)

evolutionary origin and technical function of bird flight, Part 1 and Part 2