code: def camera(self):
          
          # no camera set for the scene yet
          if not hasattr(self, '_camera') or self._camera is None:
              # will create a camera with everything in view
              return self.set_camera()
  
          return self._camera
docs: Get the single camera for the scene. If not manually
          set one will abe automatically generated.
  
          Returns
          ----------
          camera : trimesh.scene.Camera
            Camera object defined for the scene