CAT's animation layering system has been a fundamental part of the software since day one. All layer management is performed using a simple rollout called the Layer Manager (CAT).
The Layer Manager rollout is available for every bone in a CATRig. To access it, select any bone in the rig and go to the Motion panel.
Layers are Applied to an Entire CATRig
With CAT's layering system, whenever you add a new layer is added, that new layer applies to every bone in the CATRig. There’s no such thing as an arm layer or hand layer. When you add a new layer, every bone gets that new layer, and you can choose the parts of the CATRig that should not use the new layer. This process is called Feathered Weighting.
All Basic Layers Contain Standard Max Controllers
The layer system in CAT is simply a mechanism for holding and managing animation controllers. It supports all 3ds Max animation controllers, including all the various keyframe controllers such as Bezier, TCB, Linear, Quaternion, and Euler, as well as the procedural controllers such as script and expression controllers and constraints.
The Layer manager is the interface to the CATLayer system. As you animate with CAT, you this rollout serves as the center of your layering workflow. Here you can add, remove, move layers up and down , adjust and animate global or local layer weightings, and more.
The versatility of CAT's layering system is based on its support for a variety of different layer types. Each layer type has different features and serves different purposes.
CAT provides two basic modes of operation: Setup and Animation:
Blending between layers is often as simple as animating the Global Weight value for the top layer. Sometimes, however, you might want to blend between individual limbs or turn off some elements (for example, the legs) to use the animation from another layer, below the current layer on the stack. This is called Feathered Weighting. One example of this would be where you are using keyframe animation for the upper body and CATMotion for the legs.
When you add a new layer, every bone gets that new layer, and you can choose the parts of the CATRig that you do not wish to use the new layer. This process is called feathered weighting. Feathered weighting is achieved by editing the local weights of individual rig elements.
You use a layer transform gizmo to transform an animation in space. You can move and rotate the transform gizmo to change the position and direction of an animation clip. It appears as if the character is linked to the transform gizmo, but it is not. In fact, each layer has its own transform gizmo. The transform gizmo’s main purpose is to allow you to reuse animations by moving and rotating them in space.
Ranges View is CAT's nonlinear animation (NLA) view; it lets you move and retime all keyframes in a layer simultaneously. Benefits include the ability to change the animation timing and speed and trim off the end of the animation.
Time Warp curves enable you to control the velocity of an animation layer with a single spline curve. This lets you, for example, achieve Matrix-style bullet-time effects easily. The Time Warp curve can be found if you open the CATParent in the Curve Editor. You can also open it by clicking Layer Manager Curve Editor: Time Warps.
You can copy and paste animation layers, including between rigs. It is also possible to instance layers which means that different rigs can reference the same animation layer.
Use the Collapse Layers button to convert all the current animation in your layer stack to one layer. CAT will plot all your animation down to one layer using consistent sampling.
