mandarin.no

Having fiddled around with modo 401 and all its new features, I soon came to experiment with the animation features, including the new IK system. It works like a charm and when you’re used to working with modo, it just feels natural. It was very easy to rig a mechanical object that didn’t need to rely on deformations of the mesh to look convincing. But when working with organic shapes, the IK system got a bit trickier, that was until I figured out how to skin the IK.

My example doesn’t give you a perfect character rig, but it shows the basic principle. To make the mesh deform properly, you should look into using morph maps. I haven’t done so yet, but will most likely do it sometime soon.

I stumbled across a discussion on the Luxology forum (Bone deformations in Modo 302) that gave me a clue of how to do it. At first, I tried different ways of parenting the locators, deformers, channel linking and so on. But nothing seemed to do the trick. That was until I read a comment by Michael Blackbourn.

You dynamic parent the weightmap locators to a control structure.

After bending my mind around that rather minimalistic and somewhat cryptic comment, I suddenly realized what Michael was talking about. And it’s bloody simple!

Here’s how I did it:

1. Setup a chain of 3 locators, and apply IK to them.
2. Build a mesh with enough polygons to deform properly.
3. Setup 3 weight maps: one for each of the joints of the IK chain.
4. Add weight map deformers for each of the weight maps.
   And now comes the trick:
5. Hit the Compensation button (found under the Animation tab) to prevent the mesh from relocating.
6. Dynamically parent each of the weight map deformers to each of the locators of the IK chain.

That’s it!

Remember When dynamically linking an object to another you need to first select the child, and then the soon to be parent item.

I have made a short screen recording just to show how easy it is. Skinning IK in modo (About 20 Mb QuickTime) The example I show in the screen recording is not beautiful, but it shows the basic principle.

Happy animating!