FORZA MOTORSPORT’S NEW AI AND PHYSICS MAKE EVERY RACE COMPETITIVE
17 July 2023- Chris Esaki
MASTER THE CURBS WITH IMPROVED TIRE PHYSICS
We’ve already told you that the physics leap in Forza Motorsport is bigger than Forza Motorsport 5, 6 and 7 combined. This 48x improvement in tire fidelity results in a more fun and rewarding driving experience with how the car accelerates, corners, and brakes.
Previous Forza Motorsport games had only a single point of tire contact on the surface that moved at 60 cycles per second. This was problematic for curbs and rumble strips which could cause inconsistencies and unrealistic changes in suspension forces. This could also lead to tires briefly losing contact with the ground as they rolled over bumps resulting in unrealistic loss of traction.
Our new tire physics has 8 points of contact with the track surface running at 360 cycles per second. This allows tires to find grip on any type of uneven surface. The result is better drivability everywhere and realistic behavior on uneven surfaces like curbs.
CHOOSE YOUR TIRE COMPOUND
Forza Motorsport features a variety of tire compounds to support great racing and different types of competition across several decades of production cars and race cars.
Production cars will have the option to use Street, Performance, Race, or Drag tires along with the Wet tire. The Race tire is further broken into three separate compounds – Soft, Medium, and Hard. Each compound has different grip and wear characteristics. The Soft compound has the most grip, but wear out the fastest making it ideal for a Qualifying tire. The Hard compound has the least grip, but lasts the longest making it ideal for longer stints without having to pit for new tires.
There is also a Vintage tire that is used for classic cars, but it is not a selectable tire for other cars.
We’ve also dialed in the tire heat model. The biggest change is in the grip fall off at extreme tire temperatures. There is a much smoother fall off as tires reach higher temperatures, which allows for better drivability and predictability even when you are overdriving your tires.
See the July Forza Monthly replay here, where we compared a dev build view of the FM7 system vs the Forza Motorsport:
Unsatisfactory incomplete demo. Suspension physics and Tire physics are not same. In the demo only suspension behavior based on surface detected by the contact points were demod. But where is the tire physics, it’s a totally misleading demo. There’s no demo of -
Tire flexing
Tire degradation over time (visual and physics)
Tire types were not shown in action
Rubbering of tracks not shown
Dirt on tires from going off track?
Punctures?
Tire Temperature changes while driving
Don’t tell me textually or orally about these, I am asking why these were not in demo?
Because they haven’t given us a deep dive on anything so far and doesn’t seem like they will either.
There’s a great big slice of “trust us” here, which leaves a lot of open ground for speculation and hypothesis and with the amount of time this has taken, lots of scepticism.
Still 70+ days to go but I guess all will be answered soon enough.
We’ve been hearing nothing but that since FM4. How much work have they actually put into aero, braking, drag, and suspension physics? Those are elements that affect the car just as much.
No, because tire physics is something you can market and throw at everyone’s faces. it’s easy to swallow.
Tyres are the most complex piece of the simulation puzzle. aerodynamics is much simpler, braking also relies on the tyre physics along with suspension. that is why you hear tyres tyres tyres, because they will make a monumental difference to the simulation
In the announcements we are told that previously each tire has only 1 contact point and now it will be 8 points for computing the tire behavior. Meanwhile other games/sims are going to move to Finite element modeling, here’s an image from announcement from another game that is coming soon.
We really shouldn’t use the incomparable excuse anymore. These days consoles are essentially PCs. Not saying they are as powerful as the best PCs, but they are a lot closer to a PC than consoles of the past.
Assetto Corsa are 2 different builds of the title. Apples versus Apple Jacks.
No iRacing on console to compare. How does that aid your argument?
We can compare Assetto Corsa Competizione between the two. The differences are resolution, frame rates and VR Compatibility. The experience between PC and the current consoles are quite similar. Fair to say the consoles are performing like lower spec PCs, right?
The other issue with the iRacing tire model is, this is from the developers blog, right? I am absolutely sure the end product will not have finite tire points running in the background of the sim. They’ll dumb it down for final release.
Re: iracing, if consoles were so close to pc, then big sims like iracing would be running on them.
It isn’t.
They don’t compare when it comes to sim racing. The tech used in dedicated sim racers would have to be nerfed to work on consoles, like the tyre contact patch here
The iRacing pay model wouldn’t do well on consoles.
Hard core simulations don’t sell well enough for publishers to put in the effort to bring them to the consoles. If the games brought in the money, then they’d be on consoles.
FEA is the next logical step in tire behavior simulation, because, if you use a large enough number of nodes and a good mesh, there’s really nothing better. However, the computational cost can be pretty high and I wouldn’t expect anything but the highest performing PCs to run it well at this point.
Consoles are literally PCs in a compact form factor. Just because iRacing isn’t on console doesn’t mean it’s not capable of running it. In fact iRacing is so old I’m pretty sure even a ps3 could run it. It only requires 4 cpu cores and 2gb of VRAM.
The “not comparable” argument does not apply here, there or anywhere for any game anymore, because consoles became literal PCs. They both use AMD CPU/GPU architecture, and PS5 XSX/S already outperform or are on par with the vast majority of gaming PCs out there.
