Stella Toon 5
So, now that we've a character, let's animate it!!
But, how to do it?
Have you ever heard of Soft Bodies, Skinning, Armatures, Skeletons, Weight Deformation, Forward and Inverse Kinematics, etc, etc, etc.....
I guess not, specially if you're new to computer animation particularities.
The 3D world is the kingdom of barbarisms.
Please, if you want to go deep in those concepts ( useful) do a search in the Web for documentation.
The important thing here is that we'll control the character's body with a skeleton composed of bones, almost like in real life!
First thing to do, and very important, we must "clean" the mesh.
Select the model and do Ctrl-A to apply size/rotation to the mesh, or, in other words, set the size/rotation values of the mesh, to her "starting points".
If you want to scale the model ( for ex: to match an existing environement), do it acordingly to your needs, and redo Ctrl-A.
Now in side view place the cursor as in the image above and add an Armature ( our first bones of the skeleton).
I'll not explain the basics of Armatures, please, practice a bit, "outside" the tutorial.
Anyway, it's quite simple to make a skeleton. When you choose Armature in the menu, the first bone will appear at the cursor's location, a new one will start at LMB click, and so on, until you press Esc key.
The bones created this way, are automatically linked.
Check the image above.In Side view, I've made four bones in a row in one time: "root>pelvis>spine>spinehigh". Check the grey buttons in the image above at low right side, they're allready linked to her parent, "child of".
Names are important too, so don't forget to rename your bones with meaningful names.
We'll continue to make our skeleton. As we've stoped our first bones construction, we must restart somewhere. Place the cursor at the end of the last bone ( select the little yellow sphere - tip- at bone's end with LMB or Area selection, B key, and do Shift-S to snap the cursor to the bone's sphere).
When done, press E key to Extrude bone segments ( automatically linked too) or add a new armature ( that you must link manually later), all these operations in Edit mode, Tab key, of course.
Add two more bones, "neck" and "head".
It's time to parent the eyes and eyelids to the Armature ( don't forget to apply Ctrl-A to those meshes too, before).
When the Make Parent menu appear, choose the Use Bone item, and in the bones list choose the "head" one.
One leg, now ( as for the character body mesh, we'll only make a half-skeleton and then copy and mirror it).
In Side and in Front view, place the cursor like in the image above ( near the hip area).
Select the previous made Armature, enter Edit mode, and add 4 bones in side view ( use the image as a guide, but the knee must be slightly bend forward ).
An useful tip: when you rename simetrical bones ( like the arm, for ex.) apply the standard rule - "nameofthebone.L" or" .R", for left or right bones, this way, you can use some nice tools later.
To make the arm, same method as above, but now in Front view add only 3 bones and place them more or less like in the image above.
A painful task: the hand bones. Here i've choosed to make a complete hand setup ( hands are very expressive).
If not necessary, avoid this kind of skeleton setup, cause it'll slow your computer.
Make one complete finger ( with names), select and copy it four times, this way you only need to make some minor adjustements ( joint placement, bones renaming).
When a complete side of the armature is finished, it's time to duplicate it.
Place the cursor at the center of the Armature, press the Target icon in the Icons bar, or "dot" key, to center the action around the cursor, enter Edit mode, Select all the simmetrical bones ( arm, hand, leg and foot ) Copy and Mirror them.
Now, for the next task, we must have a thankfully thought to the Blender coders, that, with the new 2.27 Blender version, gave us the "auto-skinning" function . Blessed people!!
They save us lots of time of painfull work.
Let's use it! Select the model and them the armature, do Ctrl-P, choose "Armature" in the "Make Parent" menu, and finally choose "Create From the Closest Bones" item, in the "Create Vertex Groups?" menu.
Wow! All the vertex groups ( normally, one for each bone ) are automatically created, named and assigned.
Great function!! Does it work ?? Let's verify!
Now, that the model is parented to the skeleton, the bones must control the character mesh.
Select the Armature, enter Pose mode, Ctrl-Tab, the Armature turns blue, and select one bone, let's say, the uparm ( with RMB click over it).
Now, press R to rotate the bone. The arm mesh must follow the bone, like in the image above top, but, unfortunatelly, there's some troubles ( notice the distortion problem in the hand area).
The Auto-skinning function works quite well, but, has it's limits. When different bones are too near, same vertices are assigned to diferent bones and this may trouble the animation.
But this problem only needs some tweekings to be solved.
Select your mesh, enter Edit mode, and in the Edit window, in the Vertex Groups area, press the little square button ( 1), and choose the "uparm.L" group, for ex.
Then, press the Select button ( 2). All the vertices belonging to this group will be selected ( yellow dots. Look at the image above down).
The ones inside the red area are "good" but those inside the blue area are not. So, to solve this problem, deselect the "good" vertices, and then press the Remove button ( 3). The selected vertices will be retired from the "uparm.L" group.
Check all the groups, normally each vertex must be assigned to only one bone ( unless you know what you're doing), and ALL the vertices must be assigned to bones.
The next task, Bone's Weight deformation, it's more a matter of taste or perfectionism.
It's a function that controls how the bones will control the "skin" mesh deformation.
It's a quite precise and methodic task.
Attention, you can easily screw your previous work ( and mesh). Save frequently, with a different file name, this way you can return to a previous state of your work.
When Blender creates a Group ( ex: "uparm.L", 2 in the image above), he automatically assign a Weight of 1.000 to it, maximum value, 0 being the minimum.
Select your character's mesh and press the Bone little icon ( 1) in the Icons Bar, to enter Weight Paint mode.
The mesh turns to a deep flat blue colour.
We can only watch/work one group at a time.
Select the "uparm.L" group ( 2). It becames bright red ( 3) , this "tell" us that the all group's vertices have the 1.000 weight value.
Red means "full" for the weight action, Dark Blue is "no action" at all.
The Weigh Paint tool works with colours ( and with the Vertex paint tools, so it's better to bring a little Vertex Paint buttons window to the interface).
Her'e an example ( image above, 1) where "Wheight deformation" could be useful.
As you can notice, the arm joint presents some troubles when bended.
To solve the problem enter Weight Paint mode and select the "uparm.L" group in the Edit window ( 2). Set the "Weight:" button value around 0.500, and in the Paint window choose a little brush "Size" with an "Opacity" aroun 0.500 too.
Now carefully "paint" the elbow area until she became light green.
Then Select the "arm.L" group and redo the same action. Be very careful when "painting", don't go out of the group's area ( 3, red circles) or you'll have troubles when animating the model. If this happens, "repaint" the problem area with a "Weight:" value of 0, until the zone became dark blue again.
If you can't start to Weigh Paint the mesh, press the Face Select mode icon twice ( this have worked for me)?!
As you can see in the image above ( 4) there's no more disgracious zones in the model.