3D World’s question of the month

For a worm that just has to move a bit, simple methods suffice: for instance, just using a curve deform and moving the worm on a path is often enough. But if the worm is a central character, it may need to act: this means a more elaborate rig to give the animator better control over the mesh, while keeping to the toony ‘worminess’ of our hero.

The first reaction most people have to the word ‘rigging’ is to slap an armature on to the character and start painting weights. While this works for many situations, it’s far better to start by considering the problem at hand before deciding on the tools needed to solve it. Since our worm is essentially one long tube, it seems ideal to use a curve rather than bones to deform it. In this tutorial, we’ll start from there, then build on top of the curve, finally adding discrete controls for each aspect of the worm’s motion. We’ll use an armature as an elegant way to tie all the controls together. Users of other software might use discrete objects as controllers. In Blender, bones are better: they let you have multiple channels in one action, provide a rest position to go back to, and can be given customised shapes to look like any arbitrary modelled object. The downside is that you cannot simultaneously pose a bone within an armature and another object or armature, but this is a relatively small price to pay. Further advantages only become apparent in large projects, when armatures in referenced files can be proxied to animate the same linked character in multiple scenes.

In this tutorial, we’ll attempt to show you some novel ways to use a combination of object parenting, constraints and modifiers for rigging, as we encourage you to think about character set-up in new ways.

This isn’t a modelling tutorial, so we’ll begin with the worm_initial. blend file that’s included in the support files: The file has some meshes in it: the worm mesh and some pre-made meshes that will later act as shapes for the controller. However, you can model your own worm and use that instead, if you prefer.

Click here to download the support files (21MB)