                           FragColor.a = 1.0;
                        }
                    `,
                    blending: NoBlending,
                    depthTest: false,
                    depthWrite: false
                });
            }
        }

        class DarkPlanet extends Group {
            constructor() {
                super();

                // 25 degree tilt like Mars
                this.rotation.z = MathUtils.degToRad(25);
            }

            async initMesh() {
           