ros2 launch as2_gazebo_assets launch_simulation.py config_file:=<config-file>

{
    "world": "<world-name>",                // optional: deafult world if empty
    "drones": [                             // optional: no drones if empty
        {
            "model_type": "<model-name>",       // optional: default model if empty
            "model_name": "<namespace>",        // optional: default namespace if empty
            "xyz": [<x>, <y>, <z>],             // optional: [0, 0, 0] if empty
            "rpy": [<roll>, <pitch>, <yaw>],    // optional: [0, 0, 0] if empty
            "flight_time": <min>,               // optional: 0 or empty means not use battery
            "payload": [                        // optional: no sensors if none
                {
                    "model_type": "<sensor-type>",   // REQUIRED if sensor is used
                    "model_name": "<sensor-name>",   // REQUIRED if sensor is used
                    "xyz": [<x>, <y>, <z>],          // optional: [0, 0, 0] if empty
                    "rpy": [<roll>, <pitch>, <yaw>], // optional: [0, 0, 0] if empty
                },
                {
                    // Second sensor...
                }
            ]
        },
        {
            // Second drone...
        }
    ],
    "objects": [                            // optional: no objects if empty
        {    
            "model_name": "<object-name>",      // REQUIRED if object used
            "model_type": "<object-type>",      // REQUIRED if object used
            "xyz": [<x>, <y>, <z>],             // optional: [0, 0, 0] if empty
            "rpy": [<roll>, <pitch>, <yaw>],    // optional: [0, 0, 0] if empty
            "joints": ["<joint>"],              // optional: [] if empty
            "object_bridges": ["<bridge>"],     // optional: [] if empty
            "tf_broadcaster": <true/false>,     // optional: true if empty
            "use_sim_time": <true/false>        // optional: true if empty
        },
        {
            // Second object...
        }
    ]
}

{
    "world_name": "empty_gps",
    "drones": [
        {
            "model_type": "quadrotor_base",
            "model_name": "drone_sim_0",
            "xyz": [ 0.0, 0.0, 0.3 ],
            "payload": [
                {
                    "model_type": "gps",
                    "model_name": "gps"
                },
                {
                    "model_type": "hd_camera",
                    "model_name": "hd_camera"
                }
            ]
        }
    ],
    "objects": [
        {    
            "model_type": "windmill",
            "model_name": "windmill_0",
            "xyz": [ 15.0, 0.0, 0.3 ],
            "rpy": [ 0, 0, -1.57 ],
            "joints": ["motor_link_joint", "blades_link_joint"],
            "object_bridges": ["pose"]
        }
    ]
}