From BlenderWiki

First Part

Building the Rig

This tutorial covers the entire animation process of this little guy, first, creating a simple fk armature or rig, then assigning the mesh vertices to each bone using the weight painting technique, and last, animating it using non linear animation tools.

First I add the armature object I´m going to use, the 3D Cursor was located at the mesh pivot, so it gets created there. One thing to note is that in this moment the armature has a rotation value different from 0. It´s a good idea to apply the rotation value before beginning to rig and specially skin the mesh so local coordinates of the armature object are the same as the global coordinates.

Ctrl A in "Object Mode" will do the job.

I´ll turn on "X-Ray" on the armature and "Wire" display on the mesh at the "Draw extra" buttons, that helps when building the rig because you can decide were to place joints, for example in this kind of model, I like to place joints between two edge rings, not in the midle of one for better deformation.

Then, in "Object Mode" you can re-position the Armature object, the armature pivot point defines the center of object rotacion, so it´s a very important thing to place it right.

There it is, now I´ll grab the bone´s tip and extrude it a couple of times to make he bird´s back chain (set of connected bones), so that´s two for hes back and one for hes tail, the chain is NOT located in the middle of the body because he is not a worm, he got a spine in his back that allows him to move, same goes for neck etc, specially in more realistic characters.

I have added a three bone chain for the left leg and then simply duplicate it to make the other leg bone chain.

Select Linked: L hoovering on any of the chain bones can quickly select an entire bone chain.

The back and leg´s chains aren't connected by any means, so I´ll parent the legs root bones to the back bone selected in the image, this will make the leg chains to follow the back bone´s rotation, so with one leg root bone and the back bone selected (in that order) I´ll use the Ctrl P shortcut and the "Keep Offset option". The "Connected" option would make the bones to join and form a single chain but I don´t want that.

You can test your rig right away by pressing the TAB key to enter "Pose" mode, if it enters "Object" mode instead, press Ctrl TAB once to activate pose mode, then TAB will keep switching between "Pose" and "Edit" modes as I want it to be.

For the wings, I have added a new 3 bones chain, and I have used the mirror tool to place the other wing´s chain, I´m in using the "3D Cursor" pivot option to use it as the mirror center point, so I have placed it at the center of the armature. Mirror tool in armature "Edit" mode is executed by M.

Now I´ll add the root bone, this is the bone were all chains end up, when you move the root bone, you affect the entire rig, it´s used to move the whole character for example controlling up and down positions in a walk cycle (ok flight cycle), the root bone is not necessarily the object´s center of gravity so it´s not a good idea to use it for rotation while spinning or jumping in the air, etc.

As I said, I´ll parent these bones (selected in the image) to the root, tested it in "Pose" mode, works fine, good.

Now a 4 bone´s chain for the neck and head, also parented to the root.

At last, I´ll parent the beak chains to the "Head" bone this time. That´s it for the rigging, no constraints are needed in these one, just simple FK chains.

Recalculate bone normals: Ctrl N in armature "Edit" mode recalculate the selected bones "roll" normals, it´s very useful to have the bone´s Z axis pointing in the right direction.

See also

• Second part: Flying Bird - Skinning