<!-- AVATAR-FORGE · part 223 -->
	case InterpolateDiscrete:

				factoryMethod = this.InterpolantFactoryMethodDiscrete;

				break;

			case InterpolateLinear:

				factoryMethod = this.InterpolantFactoryMethodLinear;

				break;

			case InterpolateSmooth:

				factoryMethod = this.InterpolantFactoryMethodSmooth;

				break;

		}

		if ( factoryMethod === undefined ) {

			const message = 'unsupported interpolation for ' +
				this.ValueTypeName + ' keyframe track named ' + this.name;

			if ( this.createInterpolant === undefined ) {

				// fall back to default, unless the default itself is messed up
				if ( interpolation !== this.DefaultInterpolation ) {

					this.setInterpolation( this.DefaultInterpolation );

				} else {

					throw new Error( message ); // fatal, in this case

				}

			}

			console.warn( 'THREE.KeyframeTrack:', message );
			return this;

		}

		this.createInterpolant = factoryMethod;

		return this;

	}

	getInterpolation() {

		switch ( this.createInterpolant ) {

			case this.InterpolantFactoryMethodDiscrete:

				return InterpolateDiscrete;

			case this.InterpolantFactoryMethodLinear:

				return InterpolateLinear;

			case this.InterpolantFactoryMethodSmooth:

				return InterpolateSmooth;

		}

	}

	getValueSize() {

		return this.values.length / this.times.length;

	}

	// move all keyframes either forwards or backwards in time
	shift( timeOffset ) {

		if ( timeOffset !== 0.0 ) {

			const times = this.times;

			for ( let i = 0, n = times.length; i !== n; ++ i ) {

				times[ i ] += timeOffset;

			}

		}

		return this;

	}

	// scale all keyframe times by a factor (useful for frame <-> seconds conversions)
	scale( timeScale ) {

		if ( timeScale !== 1.0 ) {

			const times = this.times;

			for ( let i = 0, n = times.length; i !== n; ++ i ) {

				times[ i ] *= timeScale;

			}

		}

		return this;

	}

	// removes keyframes before and after animation without changing any values within the range [startTime, endTime].
	// IMPORTANT: We do not shift around keys to the start of the track time, because for interpolated keys this will change their values
	trim( startTime, endTime ) {

		const times = this.times,
			nKeys = times.length;

		let from = 0,
			to = nKeys - 1;

		while ( from !== nKeys && times[ from ] < startTime ) {

			++ from;

		}

		while ( to !== - 1 && times[ to ] > endTime ) {

			-- to;

		}

		++ to; // inclusive -> exclusive bound

		if ( from !== 0 || to !== nKeys ) {

			// empty tracks are forbidden, so keep at least one keyframe
			if ( from >= to ) {

				to = Math.max( to, 1 );
				from = to - 1;

			}

			const stride = this.getValueSize();
			this.times = times.slice( from, to );
			this.values = this.values.slice( from * stride, to * stride );

		}

		return this;

	}

	// ensure we do not get a GarbageInGarbageOut situation, make sure tracks are at least minimally viable
	validate() {

		let valid = true;

		const valueSize = this.getValueSize();
		if ( valueSize - Math.floor( valueSize ) !== 0 ) {

			console.error( 'THREE.KeyframeTrack: Invalid value size in track.', this );
			valid = false;

		}

		const times = this.times,
			values = this.values,

			nKeys = times.length;

		if ( nKeys === 0 ) {

			console.error( 'THREE.KeyframeTrack: Track is empty.', this );
			valid = false;

		}

		let prevTime = null;

		for ( let i = 0; i !== nKeys; i ++ ) {

			const currTime = times[ i ];

			if ( typeof currTime === 'number' && isNaN( currTime ) ) {

				console.error( 'THREE.KeyframeTrack: Time is not a valid number.', this, i, currTime );
				valid = false;
				break;

			}

			if ( prevTime !== null && prevTime > currTime ) {

				console.error( 'THREE.KeyframeTrack: Out of order keys.', this, i, currTime, prevTime );
				valid = false;
				break;

			}

			prevTime = currTime;

		}

		if ( values !== undefined ) {

			if ( isTypedArray( values ) ) {

				for ( let i = 0, n = values.length; i !== n; ++ i ) {

					const value = values[ i ];

					if ( isNaN( value ) ) {

						console.error( 'THREE.KeyframeTrack: Value is not a valid number.', this, i, value );
						valid = false;
						break;

					}

				}

			}

		}

		return valid;

	}

	// removes equivalent sequential keys as common in morph target sequences
	// (0,0,0,0,1,1,1,0,0,0,0,0,0,0) --> (0,0,1,1,0,0)
	optimize() {

		// times or values may be shared with other tracks, so overwriting is unsafe
		const times = this.times.slice(),
			values = this.values.slice(),
			stride = this.getValueSize(),

			smoothInterpolation = this.getInterpolation() === InterpolateSmooth,

			lastIndex = times.length - 1;

		let writeIndex = 1;

		for ( let i = 1; i < lastIndex; ++ i ) {

			let keep = false;

			const time = times[ i ];
			const timeNext = times[ i + 1 ];

			// remove adjacent keyframes scheduled at the same time

			if ( time !== timeNext && ( i !== 1 || time !== times[ 0 ] ) ) {

				if ( ! smoothInterpolation ) {

					// remove unnecessary keyframes same as their neighbor