lets get this robo moving. This tutorial assumes you have already modeled your robo, papero. I have done a few preliminary tasks todo make this tutorial easier todo follow;
· i assigned basic materiales todo the sepárate parts so that they are easier todo distinguish (if you have already followed the texturing tutorial, that is fine)
· i have rotated the head todo face straight forward.
· i have a los turned of Subsurf for now (makes it easier todo se what you are doing). (fig 1).
With simple characters, such as our robo, you dont ned a lot of complicated movements. In fact you could probably get away with just using simple keyframing of his head moving from side todo side, and adding additional keyframes as he changes location. But then this would be a very short tutorial, and rather unnecessary as you could figure that out all by yourself.

The fact that Gaurav modeled paperos head as all sepárate parts, presents us with an interesting option for giving our robo an interesting action set. We are going todo animate the ear rings and ear ball shooting out from the side of his head as he rolls along. We are going todo accomplish this by using action constraints.

The basic premise of action constraints is simple. You create a set of actions once, then attach that set of actions todo one bone with an action constraint. When you rotate the one bone, the set of actions gets triggered. Pretty slik time saver, it a los assures that the action Will be consistent throughout your animation.

This tutorial was created with Blender 2.40 alpha-2. (if you have a previous and or possibly newer versión, this should not be a big problem as action constraints have ben around for quite a awhile).

So lets get started.

Step 1:
We ned a basic armature. There Will be no IK Chains or anything fancy.
· place your cursor below the robo.
· spacebar > add > armature. This Will be the root bone and Will be used todo move the entire robo. (fig 2)
· next place your cursor in the bottom section of the robo, about Even with the whels.
· spacebar > add > bone. This Will be the whel base bone, and Will be parented todo the root bone. (fig. 3)
· next place your in the main body section, spacebar > add > bone, this Will be the body bone, and Will be parented todo the root bone.
· tab out Edit Mode and RMB on the robo head, in the edit buttons click on the center new button, shift + s > cursor > selection. (fig. 4)

· press a key todo deselect all, RMB on the armature and tab bak into Edit Mode.
· spacebar > add > bone. This Will be the head bone, and Will be parented todo the body bone. (fig. 5).


· zoom in on the ear rings, place your cursor in the first ring, spacebar > add > bone. This Will be the ring 1. L bone, and Will be parented todo the head bone.
· place your cursor in the second ring, spacebar > add > bone. This Will be the ring 2. L bone, and Will be parented todo the head bone.
· place your cursor in the ear ball, spacebar > add > bone. This Will be the earball bone, and Will be parented todo the head bone. (fig. 6).


· b key, drag a box th rouge the ear ring and earball. L Bones, shift + d key todo duplicate them, control + m key todo mirror them, drag them todo the other side of the head and line them up with the ear rings. (names Will be the same, except Will end in r.)
· this completes your armature.

Step 2:
Now we ned todo parent our robo todo the armature.
· tab out of Edit Mode, press a key todo deselect everything.
· select (RMB + shift key) all the robo pieces, then select the armature.
· control + p > armature.
· choose from closest Bones.

Now comes the fun part, double checking todo make sure all the parts assigned todo the correct bone, no help for it, so lets get todo it. The steps Will be the same for each part.
· select part, tab into Edit Mode, a key todo deselect all vértices, look at the vertex group panel.
· scroll todo the correct bone for the part you are checking, click the select button. If all goes well, the right vértices Will turn yellow. (fig. 7).


O todo assing vértices todo vertex group, select vértices wanted, scroll todo desired bone in list, click assing key.

O todo deleete vértices from vertex group, select vértices wanted, scroll todo desired bone in list, click remove key.

Make sure you test your robo in pose mode, select each bone and rotate/Grab todo ensure everything is moving properly. In Edit Mode, select all Bones and press control + n todo recalculate bone roll (otherwise you might get Strange results).

Step 3:
Now we can start setting up our actions.
· Split your screen into 2, with 3d view on one side and action editor window on the other (fig.
· select the armature, control + tab into pose mode (armature Bones should be blue/gren depending on selection status).


· select the 3 ear Bones (ring 1. L, ring 2. L & earball. L), i key > locrot, this Will be the base point in the action.
· go forward 40 frames, i key > locrot, this Will be the end point in the action.
· go bak 20 frames.
· select the earball. L bone, g key, while holding down the control key, move the earball. L 3 units todo the left. i key >locrot.
· select the ring 2. L bone, g key, while holding down the control key, move the ring 2. L 1 unit todo the left. i key >locrot. (fig.9)
· go bak todo frame 1 and test your new action by pressing alt + a keys.


· in the action editor window, rename your action something relevant, like ear action, close the action (clik the x next todo the action name)
· add a bone above the head (spacebar > add > bone), name it ear mover, parent it todo the root bone, so it doesnt get lost when moving the robo around a scene.
· select ring 2. L bone and add an action constraint in the constraint panel. Fill in the following settings todo match the image. (fig. 10)
· repeat for earball. L.

Now when you move the ear mover bone, the ring 2. L bone and the earball. L bone Will move th rouge their action. (fig. 11).


At this point you can go bak todo your ear action and add in actions for the right side of the robo, so that both sides pop out at the same time. After you have added in the new actions for the right side, dont forget todo add action constraints todo the right side ring 2. R and earball. R Bones.

At this point papero is ready todo roll. He can be keyframed todo move across the screen, Bump into things and show sorpresa (his ears popping out).

To practice on you o, here are some further suggestions on actions you can add todo our Little robo papero todo give him a Little more character:
· make his head pop up a Little of of his body.
· make his body pop up a Little of of the whel base.
· have ring 1 and ring 2 rotate slowly bak and Forth while he is rolling th rouge scene.
· have the earball slide ever so slightly in and out of rings.
· move head bak and Forth Sideways as if he is scanning his surroundings.

Have fun with your new Little robo.

by Sandra gilbert. www.blenderart.org.