GTA AI cars

[cant remember]

Ok, so after playing the 3D GTA's for so long they all seem to be based on the same AI principles for the cars driving around.

Traffic, when left untouched, don't drive the same way you do. ie. they don't work using the handling.cfg file or anything and aren't under the effects of gravity, braking momentum etc. They follow a invisible track so to speak.

 

Drunk/erratic drivers, drivers who flee, or that you've just crashed into suddenly 'leave' that track and become more realistic in driving. Taking turns are much longer and realistic, braking works appropriatly, they take air when they drive down a steep road etc,...)

 

This is easy to see in the porter tunnel, cars drive through the center median and the concrete on the side constantly, when you touch them they pop up on top bouncing.

Buses can take 45 degree turns into small streets in one second. It's like they spin on a middle axle.

If you lure cars on top of the SSV bridge, wait for it to raise with you and then let them drive on, they will start to fly. If you make them drive on by touching them they will fall down.

In Saint Marks, cars that suddenly go down a steep road seem to litterally stick to the road.

Cars can brake from full speed to standing still in not even 1 second. No tire marks or anything. This can especially be seen in San Andreas' highways. (you have to be on foot, they don't brake if you're in a car).

They can drive faster than you (this can only be seen in San Andreas' highway, but theoritically I think the same could go for the other GTA's if they had fast driving roads)

 

Why did they do it like that? I think that the 'unsticky' AI driving was rather good if they weren't as erratic and sloppy when taking turns.

[Demarest]

Can't tell you why they do that, but like you said, it's a factor we have to deal with in each of the GTA3D's. My biggest complaint is the AI in regards to emergency vehicles. Sometimes they'll swerve into you and when they're not, they quickly change course into you. I think this is one of the many reason GTA3 is harder than VC and SA. In SA, the emergency vehicle AI was tremendous, including cars on the other side of the road steering off even at great distances. Such is life... in GTA3

[stef_92]

Sometimes when I drive into the porter tunnel I se the cars driving on the sidewalk or in the air!! And in the exit of the tunnel for SSV sometimes the cars from the left turn into the right road ! But in and off the streets the drivers are all incompetent! Example: It often happens when I drive in in some part of the right road the cars from the other suddenly go in front me or sometimes they crash in me !

[SteaVor]

Why did they do it like that?

Because it's less strain on the processor - like you said, the cars that aren't involved with the player don't do anything more complex than following the paths, regardless of gravity or objects in their way (it's no problem for them to drive right through the corrugated iron panels that are isolating the sections of the Porter tunnel).

And the simple reason is that there are less objects that the CPU has to compute behaviour for. Simulating the complete physics and interdependencies of more than a few vehicles would've probably made the game run with more frame rate drops.

[Heihachi_73]

One thing I've had against the AI, apart from the crappy driving (e.g. right into your car during certain "perfect condition" missions), is that law enforcement vehicles can eventually go faster than you regardless of which car you have. If you have 4 stars, an Enforcer (SWAT van) can catch up to a Cheetah and make you a flaming wreck with 2 minuscule taps of the rear end. The real Enforcer is a slow POS with a zero out of ten for steering!

 

When you have 6 stars, Barracks OLs spawn as road blocks, with part of them stuck in a building (mostly seen on two-lane side roads). They become a completely solid unmovable addition to the wall, instead of a 10 ton monstrosity.

 

The Porter Tunnel has a few bugs with the AI cars - I'm surprised no-one's said anything about the cars driving partially in the wall near the Francis airport exit. If you hit or shoot them the "real" AI takes over and they get a bit of damage from the wall (haven't had one stuck in the wall though). Most of the time on the Wichita Gardens end a Landstalker spawns near the exit; tap it and it will tip over on the kerb like a runaway shopping trolley!

 

It doesn't just happen in GTA3 though - I had an Oceanic in mid air in Vice City near the petrol station (west island); it even stopped behind another car which was on the ground as normal. I shot a tyre on it and it fell to the ground! What I really don't get in VC is that the CPU crashes straight into the back of the next car if you shoot it (that is, when you can find a car where someone doesn't bail all the time!). In GTA3 the CPU car avoids everything if possible. Wonder if the GTA:LC mod has this problem...

 

The next worst thing (IMO) in GTA3 is off-topic - the time limit for Fire missions on Shoreside Vale. You can not physically get from the bottom of Wichita Gardens to Francis International in 50 seconds. You've only got the tunnel full with cars, the road along the top of Cochrane Dam, and the snake-like grade where the Firetruck slowly drifts around (taking out any unlucky cars in the way, and spinning out 180° on the solid light poles while getting full of bullets from Columbian Cartel members). I don't really use SSV for this reason, the real Pike Creek (the water between the top of SSV and Wichita Gardens/safe house) might also affect the Paramedic and Taxi missions too. Vigilante missions have a half-decent time attached to them, usually from 1 to 3 minutes.

[brucewayne909]

I wish the cars on the street would go faster in GTA. I mean, not like the chaos of the SA freeways, but not slow enough that you can walk at their speed. I've heard their slow speed is normal (with the speedometer) and it's the player who goes so fast that, in comparison, the ped in-car speed seems slow.

 

 

Edited June 17, 2007 by brucewayne909