preparing the mesh & building the armature

ma_screen01 the character mesh can be imported with one of blender's import scripts (file -> import) (or it can be modeled in blender of course). the mesh should be in a stretched out pose and it should be exactly symmetrical if you want to take advantage of mirrored armature/skin weight/animation editing. the character i use isn't textured and not perfect but good enough for the tutorial.

the origin (displayed by the little dot) of the mesh has to be centered. select the mesh object. centre new in the mesh button panel will set it to the center of the mesh's bounding box.

press [tab] to enter edit mode and press [a] to select all vertices (vertex mode has to be active in the window header). some 3d-formats like 3ds split vertices at uv-borders and other places. to have a clean mesh press rem doubles in the mesh tools button panel. it will merge vertices which are closer than the set limit. in side view move all vertices around to have the center dot approximately at the hip where the spine will start upwards.
ma_screen02 leave edit mode by hitting [tab] again (or by choosing object mode in the window header). the armature/skin weight/animation mirroring tools of blender work along the x-axis so make the character look in -y direction by rotating it correctly. move it to the center of the world along the x-axis. scale it uniformly until it has the correct size in meters (blender units best get used like meters). you can use the grid in one of the 2d views as reference. move it up until it stands on the ground plane.

after this is done the transformations have to be baked with [ctrl-a] (or 3d view header -> object -> clear/apply -> apply rotation/scale). in the transform properties panel the rotation values have to be 0 and the scale values have to be 1.

preparing the mesh - flash animation ~ 1mb
ma_screen03 switch to side view and snap the cursor to the origin of the selected character with [shift-s] (cursor->selection). the armature will be created at the cursor location (it's important that the armature has the same origin as the mesh it will be linked to).

add an armature with [space](add -> armature). the new armature will be in edit mode and there will be a first bone. enable the x-ray mode in the armature button panel. the armature will be drawn above everything else then. select the tip of the first bone and move it down like on the screenshot. extrude the other bones of the spine with [e] (accept the position of newly extruded bones with [lmb click]). you can also adjust the positions of the joints or bones afterwards.

select all bones (click on the bone itself and not on the joints) and name them root, spine1, spine2, neck, head in the armature bones button panel.

switch to object mode and bake the transformations [ctrl-a] of the armature. like for the mesh its rotation values have to be 0 and its scale values have to be 1.

(you can pan and zoom with [mmb drag] and [ctrl+mmb drag] in the buttons window just like in the 3d view! window headers can be panned left and right aswell if they don't fit to the window!)
ma_screen04 in the buttons window switch to object buttons by pressing [f7]. in the draw button panel toggle wire in the draw extra section. with the wire frame as reference placing bones is easier. switch back to edit buttons with [f9].

[rmb click] at the border between the 3d view window and the buttons window and split the 3d view window. set the left window to front view and right window to side view.

enter edit mode again for the armature. click the cursor to the position at the hip where the left leg bones should start in both views. [space] (add -> bone) adds the first leg bone. adjust its tip, extrude the other bones with [e] and place the joints like on the screenshot. select all bones of the left leg and name them leg1.L, leg2.L, foot1.L and foot2.L.

in the armature button panel enable x-axis mirror edit. duplicate the 4 selected leg bones with [shift-d] (or window header -> armature -> duplicate) and place the 4 new bones somewhere in the viewport. name them leg1.R, leg2.R, foot1.R and foot2.R (instead of renaming them manually it's also possible to select them and press [w](flip left-right names)). select the bones of the left leg again and move them slightly back and forth a few pixels. the bones of the right leg will snap to their correct position now because of the x-axis mirror edit mode which keeps bones with .L and .R postfixes symmetrical.
ma_screen05 switch the right window to top view and in both views place the cursor where the left arm bones should start at the shoulder. in the top view add the arm bones like on the screenshot and name them arm1.L, arm2.L, hand.L. mirror them like described in the previous step.

select arm1.L, arm1.R, leg1.L, leg1.R. in the armature bones button panel set the parent (child of) of the two leg bones to root and of the two arm bones to spine2.

turn on draw axes in the armature button panel. the axes should be somewhat consistent for connected bones. for example the x-axes should approximately point in the same direction for all bones of the left leg. if they don't you can try to adjust the roll angle in the transform properties panel ([n]) or try to clear the roll angle of selected bones with [ctrl-n] (or window header -> armature -> clear bone roll angle).

since this tutorial will only cover a walk cycle the armature is rather simple. i don't care for the face or fingers. maybe i will do a more elaborate tutorial (with stuff like shape keys for facial animations and a better hand setup) sometime in the future.

building the armature - flash animation ~ 3.5mb