unity GPS坐标为(X,Y,Z)，向北旋转

Question

我正在用 Unity3D 制作一个应用程序，它使用 GPS 坐标在 3D 世界中放置一个 "thing"，当你在现实世界中走近它时，你会发现它越来越近。有点像 PokemonGO

所以问题是：我设法使用函数 dist(lat1,lon1,lat2,lon2) 将对象放置在正确的位置和距离，该函数给出了 2 个坐标之间的距离（以米为单位）（见下文）。

我接下来要做的是让场景绕着Y轴转向北（Z轴+应该指向北）。我该怎么做？

我做的是这样的：

float xx = dist (0, Tlon, 0, lon), zz = dist (Tlat, 0, lat, 0);
Vector3 position = new Vector3 (xx, 0, zz);
position.Normalize ();
float beta = Mathf.Acos(position.z) * Mathf.Rad2Deg;
position = Quaternion.Euler (0,beta-Input.compass.trueHeading,0)*position;
transform.position = position;

但它确实很奇怪，"right" 位置既在我的右边又在我的左边（为什么？idk）

{dist函数，用于计算2个坐标之间的距离：}

float dist(float lat1, float lon1, float lat2, float lon2){  // generally used geo measurement function
    var R = 6378.137; // Radius of earth in KM
    var dLat = (lat2 - lat1) * Mathf.PI / 180;
    var dLon = (lon2 - lon1) * Mathf.PI / 180;
    var a = Mathf.Sin(dLat/2) * Mathf.Sin(dLat/2) +
        Mathf.Cos(lat1 * Mathf.PI / 180) * Mathf.Cos(lat2 * Mathf.PI / 180) *
        Mathf.Sin(dLon/2) * Mathf.Sin(dLon/2);
    var c = 2 * Mathf.Atan2(Mathf.Sqrt(a), Mathf.Sqrt(1-a));
    var d = R * c;
    return (float)(d * 1000); // meters
}

Answer 1

最简单的方法是将每个地图对象指定为空作为父对象，然后旋转。这样你只需要设置 transform.rotation = Quaternion.Euler (0,Input.compass.trueHeading,0) on empty as

Input.compass.trueHeading - The heading in degrees relative to the geographic North Pole

查看您的代码应该如下所示：

float xx = dist (0, Tlon, 0, lon), zz = dist (Tlat, 0, lat, 0);
Vector3 position = new Vector3 (xx, 0, zz);
position.Normalize ();
position = Quaternion.AngleAxis(Input.compass.trueHeading, Vector3.up) * position;
transform.position = position;

编辑。我不知道为什么在示例中是减号，也许它也应该在我的代码中。

transform.rotation = Quaternion.Euler(0, -Input.compass.trueHeading, 0);

Answer 2

我实际上找到了解决我自己问题的方法，那就是：

我取增量（单位北（z=轴）和实际地理北之间的差异）

if (delta == 0 && (gcb.activeSelf||head.transform.eulerAngles.y!=0)) {
    Vector3 fwd = new Vector3 (0, 0, 1);
    Vector3 north = Quaternion.Euler (0, Input.compass.trueHeading, 0) * fwd;
    delta = SignedAngle(fwd,north) + (360-head.transform.eulerAngles.y);
}

然后我计算unityNorth和应该放置元素的地方之间的角度：

float xx = dist (0, Tlon, 0, lon), zz = dist (Tlat, 0, lat, 0);
Vector3 position = new Vector3 (xx, 0, zz); //the position of the target if unityNorth and actual geoNorth were the same
position.Normalize ();
Vector3 unityN = new Vector3 (0,0,1); // unity north
angoloTrgt = Vector3.Angle (unityN, position);
position *= MIN_CUBE_DIST;
target.transform.position = new Vector3 (0,0,MIN_CUBE_DIST);

然后将物体以正确的角度放置

bollettino.transform.RotateAround (Vector3.zero, Vector3.up,  angoloTrgt - old_compass-delta);

其中old_compass是场景加载时Input.compass.trueHeading的值

unity GPS坐标为(X,Y,Z)，向北旋转

unity GPS coordinates to (X,Y,Z), rotating north

gps

unity3d

compass-geolocation