createUniqueName( originalName ) {

			const sanitizedName = THREE.PropertyBinding.sanitizeNodeName( originalName || '' );
			let name = sanitizedName;

			for ( let i = 1; this.nodeNamesUsed[ name ]; ++ i ) {

				name = sanitizedName + '_' + i;

			}

			this.nodeNamesUsed[ name ] = true;
			return name;

		}
When THREE.Object3D instances are targeted by animation, they need unique names.