5f5238f500225ada1deb09b8bab18c1b52cf2/src/BaseObject.js#L135
                this._initOptions(options);
                const {
                    altitude,
                    radius
                } = options;
                //generate geometry
                const r = layer.distanceToVector3(radius, radius).x;
                const geometry = new THREE.RingBufferGeometry(0.001, r, 20, 5, 0, Math.PI * 2);

                //Initialize internal object3d
                // https://github.com/maptalks/m