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Posted: 09 Mar 2012, 09:38
Citywalker
I was looking at what the stock cars are doing on Supermarket 2 ice, and some of them are definitely bad there. The new AI has also difficulties there with the same cars, except Pest Control and Toyeca. The rest are better, but still swing a lot before they get off the ice.
So I tried to improve their AI a bit, according to my own AI tutorial. As the Oversteer part is broken in old AI and I’m not sure about it in the new AI, I tried to make it do at least _something_ simple for both cases.

The results:

For old AI:
1) If a car runs well on ice, then using TrackAI alone doesn't make it any better.
2) If a car gets stuck on ice, then using TrackAI alone doesn't make it any better, either.
So, TrackAI alone (UnderThresh 50000 and OverThresh 50000) is good and simple for customs, but doesn’t help stocks.
3) If a car gets stuck on ice, then the next step in the tutorial can help (culling the tail-slide to 50 units, then the AI counter-turns sharply, leaving the acceleration as-is):
UnderThresh 50000
...
OverThresh 50
OverRange 1
OverMax 1
OverAccThresh 50000

For new AI:
1) Original AI is somewhat better on ice: it’s not completely stuck, but takes a lot of time swinging like mad and inching generally towards the exit.
2) If a car is unstable on ice like that, then using TrackAI alone makes it a little better, but not good.
3) If a car is unstable on ice, then the OverCulledAI above can help.

Below are comparisons for the problematic stock cars, with old AI (original) / with old AI (TrackAI) / old AI (OverCulled AI) / new AI (original) / new AI (TrackAI) / new AI (OverCulledAI):

New AI:
Sprinter: stuck on ice / same / 37:735 / unstable on ice 41:599 / 39:221 / 28:938
San: stuck on ice / same / 29:039 / unstable on ice 33:540 / 31:285 / 35:015 (misses a turn)
NY54: stuck on ice / same / 45:829 / unstable on ice 36:445 / 36:164 / 31:384
Pest: stuck on ice / same / 36:364 / stable on ice 28:125 / 37:707 / 29:826
Zipper: stuck on ice / same / 32:109 / unstable on ice 54:987 / 33:005 / 28:021
Toyeca: stuck on ice / same / 32:328 / stable on ice 25:154 / 41:962 / 32:625 (misses turns)
AMW: stuck on ice / same / 31:103 (if lucky) / unstable on ice 52:830 / 59:429 / 59:502 (not helping)
UFO: stuck on ice / same / 42:581 or 34:304 / unstable on ice 48:850 / 23:470 / 36:168
Mystery: stuck on ice / same / 43:817 or 34:043 / unstable on ice 38:252 / 42:850 / 31:038

Anyway, OverCulledAI is a double-edged sword for the AI, both old and new: it copes better on ice, and reduces some tail-swings on other surfaces, but the cars may miss a turn in some situations (the new AI has less problems with that).

Bottom line:
The new AI is better, but still not omnipotent.
Some stocks still need help on ice.
For both old and new AI: all easier vehicles (custom and stock) will go well with TrackAI alone, and difficult ones usually benefit from OverCulledAI (sometimes from TrackAI).

Posted: 23 May 2012, 10:47
Citywalker
This is how Sprinter XL should run on ice with old AI (up to rv1.2 11.0825). This makes consistent 29 second laps at Supermarket 2, and doesn’t get into stuck cycles at the ice-exit boxes if you manually crash it there.
Compare it to the newest AI (which is now hard-coded for the cars, i.e. not reading the AI values from params anymore, i.e. I can’t help you with any of the difficult cars with that version of V1.2).

;====================
; Car AI details
; Run by RewiredAI
;====================

AI { ;Start AI
UnderThresh 703.125000
UnderRange 703.125000
UnderFront 000 ; no point
UnderRear 000 ; no point
UnderMax -2 ; rerouted
OverThresh 703.125000
OverRange 703.125000
OverMax 2 ; proper for Re-Volt AI code
OverAccThresh 50000 ; switched off
OverAccRange 000 ; no point now
PickupBias 6553
BlockBias 6553
OvertakeBias 22936
Suspension 0
Aggression 0
} ; End AI


Btw, if someone has that old Caterpillar car (e.g. in Challenge Pack at RVZT), then you can try the same AI with the value of 468.750000. See it at Neighbourhood 1 (I didn’t have time to optimise it for ice.)
(Don’t bother comparing that one to the newest AI, Huki hasn’t had time to hard-code the game for this type of cars. Same happens with Skarma’s upcoming Skull Buster.)

;====================
; Car AI details
; Run by RewiredAI
;====================

AI { ;Start AI
UnderThresh 468.750000
UnderRange 468.750000
UnderFront 000 ; no point
UnderRear 000 ; no point
UnderMax -2 ; rerouted
OverThresh 468.750000
OverRange 468.750000
OverMax 2 ; proper for Re-Volt AI code
OverAccThresh 50000 ; switched off
OverAccRange 000 ; no point now
PickupBias 3276
BlockBias 3276
OvertakeBias 16383
Suspension 0
Aggression 0
} ; End AI


If you want to get the same type of results for your own cars, then use the half-step method detailed in my AI tutorial (http://z3.invisionfree.com/Our_ReVolt_P ... p=10639164) to find a suitable value for the four equal parameters, from range 0 to 2500 (“adjustment range” in the tutorial). Too low values take curves too widely, too high values swing left and right too much. For tail-happy cars on ice, use the track TC5 Ice Speed (http://rvzt.zackattackgames.com/main/co ... +Ice+Speed). For crazy cars on tarmac, use Neighbourhood 1.