cesium矩阵和方位角heading ,pitch, roll的相互转换

        // 假设当前模型的经纬度坐标为{114, 30, 1000} 方位角{heading: 30, pitch: 20, roll: 10} 都是角度来计算 
        // 1. 根据坐标, 方位角计算模型矩阵
        var position = Cesium.Cartesian3.fromDegrees(114, 30, 1000);
        var heading = Cesium.Math.toRadians(30);
        var pitch = Cesium.Math.toRadians(20);
        var roll = Cesium.Math.toRadians(10);
        var headingPitchRoll = new Cesium.HeadingPitchRoll(heading, pitch, roll);

        var m = Cesium.Transforms.headingPitchRollToFixedFrame(position, headingPitchRoll, Cesium.Ellipsoid.WGS84, Cesium.Transforms.eastNorthUpToFixedFrame, new Cesium.Matrix4());
        console.log(m);

        // 2. 根据模型的矩阵求方位角
        // 计算当前模型中心处的变换矩阵
        var m1 = Cesium.Transforms.eastNorthUpToFixedFrame(Cesium.Cartesian3.fromDegrees(114, 30, 1000), Cesium.Ellipsoid.WGS84, new Cesium.Matrix4());
        // 模型的矩阵
        var m2 = m;
        // 矩阵相除
        var m3 = Cesium.Matrix4.multiply(Cesium.Matrix4.inverse(m1, new Cesium.Matrix4()), m2, new Cesium.Matrix4());
        // 得到旋转矩阵
        var mat3 = Cesium.Matrix4.getRotation(m3, new Cesium.Matrix3());
        // 计算四元数
        var q = Cesium.Quaternion.fromRotationMatrix(mat3);
        // 计算旋转角(弧度)
        var hpr = Cesium.HeadingPitchRoll.fromQuaternion(q);
        // 得到角度
        var heading = Cesium.Math.toDegrees(hpr.heading);
        var pitch = Cesium.Math.toDegrees(hpr.pitch);
        var roll = Cesium.Math.toDegrees(hpr.roll);
        console.log('heading : ' + heading, 'pitch : ' + pitch, 'roll : ' + roll);