been trying some different mods and different tracks. is ai quality or performance a factor of the car mod, the track they are running on, or a combination of both? nothing in particular, just a general question. thanks.much.
It is a combination of Track + AI data + car physics.
Tracks need proper terrain data; racing lines must provide the best trajectories for the AI to follow; finally, track side objects must be properly configured, otherwise strange things happen (example: a certain Nurburgring version has the collision mesh for the pit separator extend INTO the track (last corner before the finish straight) - obviously, the AI racing line takes them closer to the separator and odd crashes happen then).
AI must be properly calibrated. Not all modders have the time nor the inclination to do this flawlessly.
Finally, car physics. The AI must be calibrated in order to behave adequately with a each mod physics. Change the physics, change the AI data. Otherwise, performance suffers.
The AI of GSC with default content (rcd, plr, physics files, terrain and AIW's) is the closest I have ever seen to Barry's rework of AI & track data for GTR2. Anyone mildly familiar with Reborn should know this is a true compliment: I like GSC's AI a lot.
On the other hand, with different, non-default tracks comes different terrain and AIW files and things inevitably change - unless the modders that created those tracks are "AI-aware" and were careful about it.
On top of it, with different car mods come different physics calibrations and rcd files. Very few modders are at a proficiency level comparable to the guys from the days of RSC (I'm thinking Bristow et al) , and even less are able to produce good AI for their own physics.
So: outside of the original content from Reiza, the work done on the AI could be better (for all the reasons hinted at and related to physics, rcd files, plr, terrain and aiw files).
One thing though: on the side of graphics and sounds, both Reiza and several modders have pushed the envelope of IM2. And that, to me, matters a lot.
default content is what i had in mind. thx chronus appreciated.
ps: i think graphics and sounds have still a substantial margin of improvement. well ok, sounds more than visuals.. LOD's, materials, some better spec maps for vehicles, better sun shader, some better tree shadows from texture etc. details basically. sounds, with no intention to insult Domagoj Lovric, i think wolferl or the raceroom sound engineer are the raw model to follow