const canvas1 = document.createElement('canvas');
            const context1 = canvas1.getContext('2d');
            canvas1.width = 256;
            canvas1.height = 256;
            const gradient = context1.createLinearGradient(0, 0, 0, canvas1.height / 4);
            gradient.addColorStop(0, '#777777'); // 顶部颜色
            gradient.addColorStop(1, '#000000'); // 底部颜色
            context1.fillStyle = gradient;
            context1.fillRect(0, 0, canvas1.width, canvas1.height);
            const texture1 = new THREE.CanvasTexture(canvas1);
            scene.background = texture1;