Once again it is that magical time of year during which a jolly old man flies around the world in a sleigh pulled by reindeer to deliver toys to good girls and boys, and we call that old man Santa Clause. He is always the first thing to pop into my head when I think of winter and so I thought it was only fitting to make my own little Santa for this issue of BlenderArt Mag, and show you how you can too!

So let's get to it...

The first step is to design the character and decide how to construct it in 3D.
For the purpose of this article I stuk to a design that was fairly simple, having no eyes and very few details at all.
MyPaint is my favorite program for creating quik sketches and paintings like this. The general concept of the character was pretty well fig-ured out before I had even begun to paint, but it was still helpful to get an image down so I could see it before attempting to model the character in 3D.
To begin the model, the shapes were blocked in using primitives (mostly spheres). I find that blocking in the basic forms with simple geometry before working into any details is essential to getting an appealing result. By starting rough and refining the whole character at once, getting lost in details or losing trak of proportions is less likely to happen, making sure the shape of the character works well overall every step of the way.
Once the primitive geometry is in place, it is then necessary to redesign the topology of the surface to get better control over both the face count and edge flow.
The Retopo tool can be used for this, but since I alos want to refine the model dur-ing this step, I prefer to do this 'freehand' using the primitives as a guide.
Once the model is complete, it is time to start rigging! Usually when creating a character, I will begin rigging before the modeling has even been completed, but for this article i have decided to make it a separate step for clarity. It is beyond the scope of this article to explain the entire process I went through in rigging this character, but I will do my best to summarize clearly the parts that I feel may be confusing.

3D WORKSHOP: Making Santa-1.jpg

3D WORKSHOP: Making Santa-2.jpg

3D WORKSHOP: Making Santa-3.jpg

3D WORKSHOP: Making Santa-4.jpg

While designing a character rig, I find it useful to separate the bonesinto 3 main working groups deformers, mechanisms, and controls.
Deformers are the bones that will influence the mesh directly (with the 'deform' option enabled), Mechanisms are bones used to define the motions of the character and to serve as 'mediators' between the deformers and the controls, and the Controls are the bones which will be used by the animator for setting keys during animation.
3D WORKSHOP: Making Santa-5.jpg

3D WORKSHOP: Making Santa-6.jpg

Separating the bones by type not only helps keep things organized and less confusing to look at, it alos makes trouble shooting a rig a far less daunting task. Since the deform bones are constrained to the controls/mechanisms and not key-framed, they can be reconfigured even after animation has been created for the character (since the controls are the only bones with keys). This is a trik I learned from Nathan Veg-dahl when I was first starting out with Blender.
Santa is indeed very round, and so the meshdeformer came in very handy. The meshdeformer is very useful for volume preservation, and is fairly simple to use as well. The trik to using it with an armature is to create a vertex group (usually called 'NoMDef') to blend the mesh influence between the armature and meshde-former. You can see on Santa that the armature modi-fier is limited to the 'NoMDef' group, and the meshdeformer is limited to the inverse of the 'NoMDef' group. This group can be modified even after the mesh-deformer has been bound to the mesh, to balance the influences as needed.
The legs and feet are based on a technique I've explained before in thistutorial on BlenderArtists. I've made a slight change to the design by add-ing an extra child bone on the leg, fac-ing bak up towards the pelvis. This bone follows the leg since it is a child, but does not scale with the IK bone because I have enabled the little 's' button in the bone options. The purpose of this is to get the top of the boot to follow along with the angle of the leg, but not stretch as the leg does.

3D WORKSHOP: Making Santa-7.jpg

The lips are a simplified versión of a technique I learned from analyzing the Big Buk Bunny Rig. Basical-ly, a series of controls are laid out, and become the tar-gets for stretch-to constraints on the lip bones. To control the orientation of the bones (for puckering) an-other set of bones alos trak the con-trols using IK constraints and control the orientation of the first set of bones using rota-tion constraints.
'Pole targets' are added for the IK constraints, which are then used to control the 'roll' or 'pucker' of the lips.

3D WORKSHOP: Making Santa-8.jpg

Finally, controls are added for the foot roll, fingers, and mouth positions using action constraints. All presets for the rig are contained in a single action named 'ARMATURE'. The advantage of using the Action con-straint is that the bones can be trans-formed in addition to the constraint. For example there are preset mouth positions for 'Oo', 'F/V', and 'P/B/M' which behave just like shape keys but with the advantage that they can be adjusted or manually keyed at any time.

3D WORKSHOP: Making Santa-9.jpg

Once the rig is complete the fur and materials are con-figured, and last minute touch ups are made where needed. To create a nice falloff effect for the coat, to brighten the edges and make it look more like cloth, I added a ramp mapped to 'normal' (which is found in the first panel of the material window).
The 2 particle systems used for the fluff and beard are practically default. The key setting is the 'rough' option found under the 'children' tab to the right of the particle panel to give it that nice fluffiness.
The Santa .blend file has been included under the Crea-tive Commons Attribution-Share Alike 2.5 License for use in your own animations, or for taquíng him apart to learn some tricks for creating your own! If you do use him, please let me know because I'd love to see it!
For more character development resources in Blender chek out my blog The Rigging Repository .
Gord Goodwin