Make camera setting more robust

src/jaxsim/mujoco/loaders.py

@@ -479,7 +479,7 @@ def convert(
         # Add user-defined camera
         cameras = cameras if cameras is not None else {}
         for camera in cameras if isinstance(cameras, list) else [cameras]:
-            _ = ET.SubElement(worldbody_element, "camera", **camera)
+            _ = ET.SubElement(worldbody_element, "camera", **_Camera(**camera))
 
         # ------------------------------------------------
         # Add a light following the  CoM of the first link
@@ -593,3 +593,26 @@ def convert(
             heightmap=heightmap,
             cameras=cameras,
         )
+
+class _Camera:
+    def __init__(self, name: str, mode: str, pos: str, xyaxes: str, fovy: str):
+        self.name = name
+        self.mode = mode
+        self.pos = pos
+        self.xyaxes = xyaxes
+        self.fovy = fovy
+
+    def __iter__(self):
+        if not all(key in camera for key in self.__annotations__.keys()):
+            raise ValueError("Missing keys in camera dictionary")
+
+        if not all(isinstance(self.key, str) for key in self.__annotations__.keys()):
+            raise ValueError("Values must be strings")
+
+        if len(self.pos.split()) != 3:
+            raise ValueError("pos must have three values separated by space")
+
+        if len(self.xyaxes.split()) != 6:
+            raise ValueError("xyaxes must have six values separated by space")
+
+        return tuple(self.key for key in self.__annotations__.keys())