What problem does it solve? Animating 3D objects in Three.js requires coordinating AnimationClips, AnimationMixers, and AnimationActions, plus handling GLTF skeletal data and morph targets, which is error-prone without a structured reference. ## Core Features & Use Cases - Keyframe Animation: Create NumberKeyframeTrack, VectorKeyframeTrack, QuaternionKeyframeTrack, and ColorKeyframeTrack clips with configurable interpolation modes. - GLTF & Skeletal Animation: Load GLTF animations, control bones programmatically, and attach objects to skeleton bones. - Animation Blending: Crossfade between actions, blend idle/walk/run states by weight, and apply additive blending layers. - Use Case: When building a character controller, use this Skill to load a GLTF model, play its Walk clip through an AnimationMixer, and smoothly crossfade to a Run clip based on movement speed. ## Quick Start Use the threejs-animation skill to load my model.glb file and play its Walk animation with a crossfade to Idle when the character stops moving.