N2003 LP Files

Written For Roadcourses


by fortine_oo


(Ed note: You will need to use the reflap tool to make LP files... tool is available at The Pits as part of their Editing Tools package .)

The only speed sensitive lp is the "race lp".

The "raceline lp" is only a visual line used by the player as a driving line reference. It is usually a copy of the race lp, but it may be any line made using the reflap tool. The minrace, maxrace, minpanic, maxpanic, and limp lp's can be driven as fast or slow, it doesn't matter.

The "limp lp" has no keyboard entry to turn it on to see it in the game. If you want to see it on the track you'll need to rename it as one of the other lp's, and then activate the visual by using the proper keystroke. The "limp lp" is needed for ai that have run out of fuel or had some mechanical malfunction. It provides a path out of the race traffic that will get them back to the pits. It should be on the same side of the track that the pits are located. It can run on the edge of the track, but if there is a conflict with the racing line, I don't hesitate to let it run just off the racing surface. The limp lp does not run through the pits, but it does make a complete circuit of the track.

The "maxrace lp" ( the left light green line when viewed from the car ) and the "minrace lp" ( the right light green line when viewed from the car ) are the left and right sides of the ai's driving space. ( All max lp's are on the left, and min lp's on the right. )The farther apart these are, the more side by side racing can occur ( doesn't mean that it will ) and the more racing room the ai will have. Sometimes more room means less competitive racing because the ai may use that space which isn't a good racing line and then just lose momentum. There are instances where you'll want to pinch them closer together, to just concentrate the racing or to encourage the ai to take the most beneficial path, or for reasons that present themselves on specific tracks. Using knowledge of the racing line and racing tactics is the best way to decide where to put the minrace and maxrace lp's in relation to the race lp; decide how you'd race the space if another car was in your way on the preferred line.

The "maxpanic lp" and the "minpanic lp" are further extensions of the racing space. They tell the ai where the maximim racing limits are. They can cover the entire racing surface and even off track surface, they're mostly used for collision avoidance.

There are two sets of pit lp's. Normally, only one set is needed, pit0, maxpit0, and minpit0. The second set is only used if there is a second set of pits, a second pit lane. These would be pit1, maxpit1, and minpit1. The "pit0 lp" is partially used by the pace car when it's on the track. The min/maxpit are only used by the ai when approaching pit road to enter the pits, while driving through the pits, and finally as a route back onto the track. It's good to try and make pit0 come in line with the "race lp" near the entrance to and exit from the pits because it let's the ai make a smooth, fluid transition in and out of the pits. The ai will normally use the pit0 ( or pit1 ) to access the pits unless there are two ai close together, in which case one will possibly use the min/maxpit. It is also not unheard of to have the ai use the min/maxpit lp that's closest to the racing line when entering the pits, although it's less likely to happen when exiting the pits unles two ai are side by side. I have never seen the ai use the lp on pit lane that's the farthest from the pits ( the one closer to the track ). So if you have a narrow pit lane, make the lp closer to the track follow the same line as the pit0 lp, thus giving the ai two, more spacious paths. I try and keep the closest to the pitboxes lp about half car width from the pitbox line. Then make the pit0 lp 2 1/2 car widths from that lp toward the track. the third lp can go in the remaining space. When entering or exiting pit lane, the three lp's should be sufficiently separated to allow for three cars side by side. Remember to find a safe path for the cars returning to the track to stay out of the way of the racing traffic, until they can safely merge.

The "race lp", the king of the lp's. When you make one in reflap, every movement is recorded. If you can drive it as fast as a real race lap, tweaking the ai will be significantly easier, you'll not have to "make up" information. This allows for greater flexibility when assigning values in the track ini because you will be fine tuning instead of building a competitor. But, you cannot usually drive a reflap lap like a race lap. When racing you can freely use all the mechanical features of the car, steering, throttle, brakes, and drift. As I said, everything is recorded, and the ai will amplify every recording. When you adjust the direction, they'll TURN THE WHEEL. When you lift the throttle, they'll BACK OFF THE GAS. Etc., etc. You just have to drive the fastest laptime you've ever driven at the track, and do it with ultra smooth steering and throttle control, while keeping the car as glued to a single line ( no drifting and definitely no opposite wheel lock ) as you never have. I have run lp laps with increased grip to limit drift and help braking, but I've found that somehow the physics engine knows this and you need to have a laptime that's 1 1/2 to 2 seconds faster just to end up with an lp that's equivalent to a non-enhanced grip laptime. (Ed. note: Italics inserted by me... because this exactly what I needed to know my for my first LP's; I used some misinformation, increased the grip, and ended up with a pretty raceline but worthless race lp) It's easiest to get the smoothest, fastest lap driving a gtp car, and the lp translates to the other series just fine. That is, as long as the track doesn't have very fast no lift corners for gtp cars. Cup cars need to at least lift at most corners, and if you don't tell them where and how much, they'll make up there own mind and they play it very safe ( i.e. slow ). So in that case it's best to use a series that can use less throttle. Because pta has some downforce, that's my first choice. But if you don't drive those cars normally, you may not get a good enough lap. Cts might work just as well because they're fairly balanced, the power to weight ratio is balanced enough to easily keep it in control, and with the right setup they're pretty easy to drive smoothly. Cup would not be my choice. They're heavy, got way too much power, and they don't like to turn. But if cup is your forte, give it a shot.

Two things that give the ai fits, fast corners and esses. Ai want to brake, or at the very least slow down, for corners. They also want to turn the wheel. As far as turning, make the turning happen on an early or late apex. This allows for a little steering movement without actually turning the wheel ( remember, the ai will exaggerate everthing ). Just sort of apply pressure to the wheel like pushing on the handlebars of a bike when going around a corner. When approaching the corner from a long straight, ease gently off the gas but not completely. Hold a constant throttle, and then when going through the corner slowly keep applying throttle to continue to gain speed until the next shift point. If you have to back off the gas mid corner to "make it", the ai will read that and magnify it. They'll drop 5+mph in a nano second, and that'll kill the acceleration and their laptime will rise significantly, not to mention that if you're following them you'll just run 'em over. Sometimes you'll have to "gear" your setup to to deal with this situation. The other ai bugger is esses. Like I said, ai like to turn when the track does, especially the second turn. You can fool 'em on the first by making a late apex entrance, but they're gonna turn the second time. Three aids to combat this, 1) the acceleration through the bend ( just like the fast corner ), 2) leaning on the wheel ( just like the bike ), and 3) run the lp off track through the apex. The ai are still going to turn the wheel, but hopefully it will be less than they would usually do. They're also going to resist leaving the racing surface, but the further you went off when making the lp, the harder it is for them to stay completely on, so they may get two wheels off which means they'll turn less. When they're allowed to do it their way, it usually results in a tail swinging slide that really slows them down. Make sure the min/maxrace lp goes even further, they're often less resistant if they don't feel the proximity of that next line.

As far as the race lp in general, the ai pick and choose when to follow it exactly. Much of the time the speed and momentum of the car is allowed to take the path of least resistance. And at some places on some laps they'll actually take a slightly straighter line to the next apex than you gave them. So if you have a section(s) of the track that are wider or have some runoff pavement, run that lp through it. Mostly they'll follow it, but occasionally they'll shorten it, especially if they're considering a pass. If you don't get the lp in there ( the extra space ), they'll likely never use that space. On long sweepers, hold the line a little tighter to the inside, the ai almost always drift out on these trying keep up maximum speed.

Another problem area for getting a smooth lap are when the track drops abruptly and the car tries to launch itself. For some reason, this always seems to occur at a braking or acceleration zone. This imperfection has no affect on the ai, but it sure makes it hard to get a clean, controlled lap. I don't have an answer for that except softer shock rebound on the rear and stiffer fronts for drop offs, and softer rebound at both ends for up jumps.

That's about it. You can't screw it up so try anything, you can always make more.

fortine_oo
10-4-06