Support for Backward Driving in Autopilot Mode

[Ezharjan]

Environment

CARLA version: 0.9.13 Platform/OS: Ubuntu 20.04 LTS

Problem

In a scenario in which all the vehicles are being driven in autopilot mode, I've tried to set the vehicle_control.gear = -1 and vehicle_control.reverse = True so as to make all the vehicles (or one of the vehicles) drive backward. But they drive forward. I found in the documentation that the vehicle_control.gear = -1 means vehicle is running on back gear, not backward, nor does it mention how to make the vehicles drive backward in autopilot mode.

Expectation

The vehicle(s) that I set vehicle_control.gear = -1 and vehicle_control.reverse = True drives backward.

Steps to reproduce

1. Spawn vehicle(s);
2. Get vehicle controller(s);
3. For all/one of the vehicles, get their controllers and set_autopilot(True).
4. Set vehicle_control.gear = -1 and vehicle_control.reverse = True
5. Start simulation.