I noticed when I view the racing line in LFS that some of the trajectory paths are ones that the fastest driver's don't follow and either turn in too soon or too late in relation to the turns. I dissected nearly all the turns to bisect the angles to calculate the real apex positions and mapped out all the geometric apexes. I noticed that some of the racing lines in the game didn't use the largest arc radius allowable for single turns, and a more complex system of arc radii for S-section turns where the largest arc radius is found in the final turn.

My question is how are the racing lines calculated in LFS? Is it by the fastest hotlap set, by mathematical breakdown and calculation of the turn angles, or by some other method?

In the images below, I took a snap of the game to show exactly what I mean. (Click to enlarge)





The green line represents the in-game trajectory path but it's not allowing the car to take the largest arc radius possible. It actually cuts into the turn much sooner forcing the car into a smaller turn radius that apexes the corner before the geometric apex.

The yellow line represents the line I calculated for that corner to be the largest arc radius allowable which if you've raced on KY oval before, you'll notice as well that the turn in point and trajectory path is about the same line where the fastest drivers position their cars as well.

Sorry it's a bit of a complex question to explain which is one I've been wanting to ask for a while. I created images for another project which relates to it and it helps to explain the question.

The racing line in LFS is not supposed to be optimal, just "good enough" for beginners, so they have something to follow and learn from.

How it is calculated... I'm not sure, I think nowadays it's done fully by the AI opponents without any hints? I think it was set by hand in editor before, but it may be fully dynamic now... if you are bored, try to search Scawen's posts about AI improvements, I think several years ago he did mention also racing line in one of them? But I may be wrong. .. Anyway, don't expect the racing line to be optimal, it's not supposed to be, that one I remember well.

The racing line is the same shown for all cars as far as I know.

So it is just a help to get used to the tracks a bit. Greets PVL.

Racing line is different for all cars in some way or another PVL. Braking points change, Entry lines change, its just used as a guidance line for beginners to get a feel for their car and the track.

Also, the ideal racing line isn't necessarily what you'd calculate mathematically - it usually is for simple corners, especially when not laterally grip limited, but more complex corners or close sequences of corners can be very different.

It often also varies depending on the car. For example, the different drive configurations (RWD/4WD/FWD) of the TBO cars mean that one corner have very different fastest lines for the different cars, even though they have similar performance.