I think it's worth splitting the two things up which make a sim. The engine, and the models.
I think ISI's engine is very good. It has to be. That's what makes it so good for modders, why so many other developers license it, and what enables rFPro. It's also apparent in their stuff like RealRoad that they can track a lot of things to make a dynamic track that a customer (modder or otherwise) doesn't need to put a lot of effort into. On the engine side, iRacing certainly lags behind, their dynamic lighting, track, and other projects are still in development.
But the engine is just half of the picture. Without plugging in solid models and populating those models with good data, the engine isn't worth much. Your 'sim' will run well, but it won't correlate to reality. This is not to say iRacing necessarily does a great job, but if the question is whether ISI does well on this side I'm not sure that would be the common opinion. Why do we think Reiza gets so many more accolades on car handling? More to the point, my understanding is many (or most) rFPro customers are plugging in their own tire and car models, among whatever other physics code they need.
tl;dr, rFPro shows how well developed the ISI engine is, but not necessarily their modeling which teams like Reiza seem much more proficient at.
Interesting post.
1- That's a battle I have been "fighting" for years. One thing is the core physics (of any sim), another is the data (the calibration) you have to feed it. It's like this with flight sims, it's like this with racing sims or even space flight sims. Same thing.
A lot of uninformed gamers, now siding with this or that next-gen sim, qualify ISIMotor2 as deficient or even bad (there's a known poster who even called ISIMotor2 and sims based on it as "arcade" games, go figure) because rFactor/GTR2/RACE07 have collected more than enough deficient, or outright bad mods. This only happened (both the bad modding, and the bad rap) because ISIMotor2 is open to modding and exploration of its physics.
The problem with ISIMotor2 is not the core physics, not the physics engine or even the game engine itself (though it's not imperfection free). The problem is the calibration models that modders and developers (from ISI, to SIMBIN and Blimey/SMS) have designed for it.
And the same could be said about NetKar Pro (exception made of the Gallardo mod), LFS or iRacing, with
one major difference:
none of these are open to scrutiny, to exploration and modding. Whatever is wrong with them can only be discerned through:
- (a) handling (and this requires either simracing hardcore experience or actual racing experience) or
- (b) telemetry (and only a fraction of simracers are knowledgeable; I doubt casual gamers even care enough to look at data sheets summations, let alone full telemetry) and a sheet of paper for some basic physics calculations.
So, on one hand, we have a very good physics engine (and game engine) , providing enormous flexibility and ample solutions to model cars.
On the other hand we have solid sims (NKP, LFS, iR) which are not open to modding.
None are flawless - which doesn't mean we can't discern degrees of precision and accuracy, because we can. We can't, however, know for sure if it's the physics engine or the physics calibration at fault in the case of NKP, LFS or iRacing.
That's the problem with iRacing: which is at fault? Dave Kaemmer's physics engine (as a whole, and the TM in particular) or the physics calibration people? No way of knowing yet - judging from the curriculum of current vehicle dynamicist Chris Lerch, after he has reviewed all models (past his Z4 GT3), if there are still faults these will be traced back to the physics engine.
2- That, however, is only part of the picture in regards to physics. There's also things related to the modelling programming itself (tick rates, solvers, error propagation, etc, etc). If ground collisions/detection are faulty, if the solvers used give rise to instabilities, they will have serious problems to contend with.
3- Reiza and their proficiency, which parallels the work done by a handful of modding groups. Some groups not only devise proper ways of dealing with physics engine, but also (oddly enough) have access to better, more extensive data than some developers do. They're also free of constraints - modding has one focus, which is authenticity mixed with uniqueness, both of which are certainly NOT the focus of most developers (which tend to mass produce or recycle, and worse still, target a much wider and less demanding audience).
As I said, one interesting post with a few inevitable followup thoughts.
PS: Chris DiBen. and I participated in those super-heated discussions spawned by Dave's initial thread about the newly release NTM. To the observant eye, those discussions explained much of what is still happening now.
And yes, in spite of the price, for some iRacing is worth it - hopefully, the physics issues will (someday...) get sorted out.
