//axis 坐标辅助
var lineXYZ = scene.addChild(new Laya.PixelLineSprite3D(3));
lineXYZ.addLine(new Laya.Vector3(0, 0, 0), new Laya.Vector3(50, 0, 0), Laya.Color.RED, Laya.Color.RED);
lineXYZ.addLine(new Laya.Vector3(0, 0, 0), new Laya.Vector3(0, 50, 0), Laya.Color.GREEN, Laya.Color.GREEN);
lineXYZ.addLine(new Laya.Vector3(0, 0, 0), new Laya.Vector3(0, 0, 50), Laya.Color.BLUE, Laya.Color.BLUE);
