The CAT Motion layer is use to apply procedurally generated motion to a CAT rig. This oftentimes is used to quickly test out the skinning work done on a character as a way of getting up and running quickly with a character's walk or run cycle. We can even use it for final animation once we've edited it using the CAT's Motion editor. Let's take a look at how we apply at how we apply CAT Motion to our rig by selecting a bone and coming up to the Motion tab. Then we can right-click and choose our Layer Manager rollout.
Once there, we will come down and click and hold on our Add layer button, come all the way down to the bottom and release our mouse to add a CAT Motion layer. By default this layer will add a basic procedural walk to our CAT rig. We can view this motion by enabling Animation mode and then pressing play in 3ds Max's animation controls. Here of course, we have applied the motion to a standard bipedal character, but we could just as easily have used a horse, spider, or centipede rig, and our CAT Motion layer could still be applied.
Directing our attention back to the Animation layer stack, you'll notice that with a CAT Motion layer we now get a new button that gives us access to a our CAT Motion editor. This gives us the ability to control and refine the procedural motion we have added to our rig. If I just double-click the two legs option and then double-click a Procedural Motion, we get a new dialog box. This asks if we want to load our motion into a new layer. I'll load it into an existing layer or replace the motion we already have applied.
I'm going to choose Load Into New Layer and then click Load. As you can see, we have another entry in our current layer's list. This stack works in the same layer as CAT's Animation Layer Manager and is calculated from the top down. As you can see, we can even use the Weight tool to blend multiple motions together. Being able to layer up multiple motions gives us the ability to experiment with and create unique motions within a single CAT Motion layer.
We can also, of course, in the Layer Manager rollout, add Adjustment layers on top of our CAT Motion to refine and to change it. We can even stack all the CAT Motion Layers and then weight them according to our needs. Having a powerful Procedural Motion Generator available to us, once again, opens up a number of options and possibilities when working with CAT. Of course, applying a CAT Motion layer is only the start of proceedings. This is why in Chapter 7 we will be focusing exclusively on using the CAT Motion editor.
- What is CAT?
- Using and editing preset rigs
- Repositioning bone pivots
- Using CAT control gizmos
- Working with spines
- Adding limbs to a character
- Working with adjustment and motion layers
- Animating with the foot pivot system
- Building a start-to-finish rig with CAT