PX4 SITL MAVROS - Creating Setpoints in Body Frame

I have recently started trying to build a vision based controller for a drone. To test this I have been using the PX4 SITL setup in combination with MAVROS in a Gazebo simulation environment.

Using a depth camera, I first detect the relative position of an object that I would like to fly towards in the body frame of the drone (the frame that moves and rotates with the drone). I would like to pass this as a setpoint to the flight controller, but when I try to do this using the topic /mavros/setpoint_position/local I have noticed that the frame used is actually the ENU fixed frame.

I have tried to convert the setpoint from the body frame to this fixed frame using a tf transform but was unsuccesful. Even if I had succeeded in my case it would make much more sense to be able to define position (or even better velocity) setpoints in a body frame that moved with the drone.

I have spent quite a while browsing through different forums but have as of yet not been able to find anything that was able to tell me how to do this. I think it should be possible to change the MAV_FRAME parameter to a body frame in the configurations somewhere, but I was also unable to find out how to do this.

I am quite new to the PX4 autopilot and MAVLink/MAVROS so I would not be surprised at all if I am missing something obvious. Thanks for the help!