With Forza Motorsport, our goal was to make the AI more competitive with our fastest players. We run the simulation through thousands of laps on a per track layout, per car type basis. This builds a custom racing line, enabling the AI to drive really fast on any given track. To dial in the AI system, we also gathered feedback from the community, including sim-racers and professional racing drivers, to help us achieve the desired pace and proficiency. This process even included input from some of our own designers here at Turn 10, who compete in autocross and racing events in their free time.
When driving in traffic, the system frequently moves to a dynamic racing line as the Drivatars try to find their own ideal line on the track. This can result in sub-optimal driving performance, such as collisions, AI driving off track, or things that a professional driver would not do. Here is what we would like to see in our Drivatar AI to ensure you can enjoy fun and engaging single-player racing:
- Faster, even when they are not on the optimal racing line.
- Skilled and defensive, providing exciting competition.
- Capable of overtaking the player and passing other AI opponents without veering off track.
- Able to better limit collisions and off-track behaviors, including awkward mergers when they attempt to return to the ideal racing line.
To get us closer to the outcomes listed above, we've developed and will be releasing a multi-line AI system that is trained on multiple lines of traffic, giving Drivatars more options for the optimized racing lines they can follow. This update should improve side-by-side racing in heavy traffic scenarios, allowing AI to skillfully and consistently race without erratic driving behavior when it's not forced to stay on the optimal line.
