{number} [duration=-1] - The clip's duration in seconds. If a negative value is passed, * the duration will be calculated from the passed keyframes. * @param {Array} tracks - An array of keyframe tracks. * @param {(NormalAnimationBlendMode|AdditiveAnimationBlendMode)} [blendMode=NormalAnimationBlendMode] - Defines how the animation * is blended/combined when two or more animations are simultaneously played. */ constructor( name = '', duration = -1, tracks = [], blendMode = NormalAnimationBlendMode ) { /** * The clip's name. * * @type {string} */ this.name = name; /** * An array of keyframe tracks. * * @type {Array} */ this.tracks = tracks; /** * The clip's duration in seconds. * * @type {number} */ this.duration = duration; /** * Defines how the animation is blended/combined when two or more animations * are simultaneously played. * * @type {(NormalAnimationBlendMode|AdditiveAnimationBlendMode)} */ this.blendMode = blendMode; /** * The UUID of the animation clip. * * @type {string} * @readonly */ this.uuid = generateUUID(); /** * An object that can be used to store custom data about the animation clip. * It should not hold references to functions as these will not be cloned. * * @type {Object} */ this.userData = {}; // this means it should figure out its duration by scanning the tracks if ( this.duration < 0 ) { this.resetDuration(); } } /** * Factory method for creating an animation clip from the given JSON. * * @static * @param {Object} json - The serialized animation clip. * @return {AnimationClip} The new animation clip. */ static parse( json ) { const tracks = [], jsonTracks = json.tracks, frameTime = 1.0 / ( json.fps || 1.0 ); for ( let i = 0, n = jsonTracks.length; i !== n; ++ i ) { tracks.push( parseKeyframeTrack( jsonTracks[ i ] ).scale( frameTime ) ); } const clip = new this( json.name, json.duration, tracks, json.blendMode ); clip.uuid = json.uuid; clip.userData = JSON.parse( json.userData || '{}' ); return clip; } /** * Serializes the given animation clip into JSON. * * @static * @param {AnimationClip} clip - The animation clip to serialize. * @return {Object} The JSON object. */ static toJSON( clip ) { const tracks = [], clipTracks = clip.tracks; const json = { 'name': clip.name, 'duration': clip.duration, 'tracks': tracks, 'uuid': clip.uuid, 'blendMode': clip.blendMode, 'userData': JSON.stringify( clip.userData ), }; for ( let i = 0, n = clipTracks.length; i !== n; ++ i ) { tracks.push( KeyframeTrack.toJSON( clipTracks[ i ] ) ); } return json; } /** * Returns a new animation clip from the passed morph targets array of a * geometry, taking a name and the number of frames per second. * * Note: The fps parameter is required, but the animation speed can be * overridden via {@link AnimationAction#setDuration}. * * @static * @param {string} name - The name of the animation clip. * @param {Array