load(url) {
        return new Promise(resolve => {
            this.require([
                'ColladaLoader',
                'KMZLoader'
            ]).then(() => {
                var loader = new THREE.KMZLoader();

                loader.load(url, collada => {
                    var obj3d = collada.scene;
                    resolve(obj3d);
                }, undefined, () => {
                    resolve(null);
                });
            });
        });
    }
KMZLoader
@author tengge / https://github.com/tengge1