In my xml model ,I have 12 joints, which all use motor as actuators. In the end of the model, I have actuator portion, <actuator> <motor name="hipRoll0Transmission" joint="hipRoll0" gear="186" /> <motor name="hipPitch0Transmission" joint="hipPitch0" gear="30" /> <motor name="knee0Transmission" joint="knee0" gear="30" /> <motor name="hipRoll1Transmission" joint="hipRoll1" gear="186" /> <motor name="hipPitch1Transmission" joint="hipPitch1" gear="30" /> <motor name="knee1Transmission" joint="knee1" gear="30" /> <motor name="hipRoll2Transmission" joint="hipRoll2" gear="186" /> <motor name="hipPitch2Transmission" joint="hipPitch2" gear="30" /> <motor name="knee2Transmission" joint="knee2" gear="30" /> <motor name="hipRoll3Transmission" joint="hipRoll3" gear="186" /> <motor name="hipPitch3Transmission" joint="hipPitch3" gear="30" /> <motor name="knee3Transmission" joint="knee3" gear="30" /> </actuator> Note the sequence of motors shown up is not same as that of joints. When coding a torque input for it, I'm not very sure how ctrl maps to the actuators I put on the joints. Does the sequence of ctrl follow the sequence of the joints shown up in the model? Or does it follow the sequence of motor shown up in the model? Or it has some other relationship? Thank you!