record-simulation

Use the CARLA Python API client.start_recorder(file, additional_data) to begin recording and client.stop_recorder() to end it. The Skill's record.py script wraps this with start, stop, and clip commands, and verifies the log by parsing it back from the server.

The recorder captures world state per frame: actor spawns and destroys, transforms, traffic-light states, vehicle wheel and animation data, and walker bone poses. With additional_data enabled it also records velocities, accelerations, and control inputs.

No, the recorder does not store sensor output such as camera images or lidar point clouds. On replay you re-attach sensors and enable replay_sensors to regenerate that data from the replayed world state.

The .log file is written on the server's filesystem, not the client. A relative filename lands under the server's CarlaUE4/Saved/ directory, so pass an absolute path to control exactly where it goes.

A zero-frame log means nothing simulated between start and stop, or the server-side path was wrong. Ensure actors are actually moving during the recording window and use an absolute writable path on the server machine.