Added SphericalToCartesian method

NewHorizons/Utility/CoordinateUtilities.cs

@@ -1,17 +1,49 @@
-using UnityEngine;
+using UnityEngine;
 namespace NewHorizons.Utility
 {
     public static class CoordinateUtilities
     {
+        // Longitude and latitude are in degrees
+        // Using the phi and theta convention used on https://mathworld.wolfram.com/SphericalCoordinates.html (Mathematics not physics convention)
         public static Vector3 CartesianToSpherical(Vector3 v)
         {
             float dist = Mathf.Sqrt(v.x * v.x + v.y * v.y + v.z * v.z);
-            float latitude = (Mathf.Rad2Deg * Mathf.Acos(v.z / dist));
+
+            // theta
             float longitude = 180f;
             if (v.x > 0) longitude = Mathf.Rad2Deg * Mathf.Atan(v.y / v.x);
             if (v.x < 0) longitude = Mathf.Rad2Deg * (Mathf.Atan(v.y / v.x) + Mathf.PI);
 
+            // phi
+            float latitude = (Mathf.Rad2Deg * Mathf.Acos(v.z / dist));
+
             return new Vector3(longitude, latitude, dist);
         }
+
+        public static Vector3 CartesianToSpherical(float x, float y, float z)
+        {
+            return CartesianToSpherical(new Vector3(x, y, z));
+        }
+
+        public static Vector3 SphericalToCartesian(Vector3 v)
+        {
+            var longitude = v.x;
+            var latitude = v.y;
+            var r = v.z;
+
+            return SphericalToCartesian(longitude, latitude, r);
+        }
+
+        public static Vector3 SphericalToCartesian(float longitude, float latitude, float radius)
+        {
+            var theta = Mathf.Deg2Rad * longitude;
+            var phi = Mathf.Deg2Rad * latitude;
+
+            var x = radius * Mathf.Cos(theta) * Mathf.Sin(phi);
+            var y = radius * Mathf.Sin(theta) * Mathf.Sin(phi);
+            var z = radius * Mathf.Cos(phi);
+
+            return new Vector3(x, y, z);
+        }
     }
 }