New Assetto Corsa Competizione Physics Blog Post

Paul Jeffrey

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ACC Aris Blog.jpg

Aristotelis Vasilakos of Kunos Simulazioni has started a new blog post series, digging deeper into the physics of the upcoming Assetto Corsa Comeptizione…


As the initial 'Early Access' release of Assetto Corsa Competizione begins in just one week's time, the team over at Kunos Simulazioni continue to be hard at work behind the scenes making adjustments and improvements to this hotly anticipated new simulation.

Already we have learnt much about the content and direction of ACC, however one of the things that are perhaps most anticipated by the community must be the physics of ACC, and how they will compare in a brand new game engine alongside the highly regarded original title.

To help shed some light on the subject, and build up the hype, ACC physics guru @Aristotelis has shared a brilliant new blog posting, the first of a proposed series of posts on the inside workings of the physics for ACC.

You can check out the full blog posting from Aris below:

Hello everybody!

The Assetto Corsa Competizione Early Access is about to begin and once again we’re ready to start a fantastic journey.

First things first, Early Access means that you get the opportunity to get early versions of the final game and have a look on the development and evolution of ACC. Obviously, once you bought the EA version, you get all the following updates of the main game for free. On the other hand we, developers, get the opportunity to collect feedback and impressions while we work, from a much bigger testing team the we could ever organize in private.

Our responsibility will be to try and update the title on the pre-announced dates, offering great new content and as stable features as possible, so that you guys can enjoy the game and keep the feedback coming.

Obviously, that means that the initial versions of the game will have limited content and features, but we are confident that we can offer the same successful evolution experience as we did with AC Early Access period.

I hope that the above is clear for everybody and the community can spread the word and inform other simracers that might not know what Early Access means.

While many of ACC gameplay features won’t be available in the first releases of Early Access, the driving physics simulation is mostly ready. Some fine tuning and some extra features are still needed, but… there’s plenty to talk about so let’s talk… physics!

So what physics ACC runs? The first test Stefano did when we started exploring the Unreal Engine, was create a version of our AC physics and make it run inside UE. I won’t go into details, I won’t even know how to explain it, but after lot’s of cursing, insomnia and head scratching, he made it. So the first initial versions of ACC had the AC physics running.

Next step and part my main job for the time, was to try and do as many parallel runs between AC and ACC:UE to make sure the physics was absolutely identical, trying to eliminate any possible placebo effects, doing laptimes comparisons and handling comparisons. Once we got absolutely sure that everything was identical, the fun part (or the nightmare part, depending on how you see it), began.

The initial idea about ACC physics, was to evolve and improve weak points of AC physics and then move on from there. Not sure if we skipped it completely or gradually moved from one plan to another… too many things have happened and to be honest, considering the end result, it doesn’t matter anymore. What it does matter is that ACC, although it might “feel” similar, it certainly is much more than that. Stefano will probably call it evolutionary, but to be honest there’s so much new stuff that I’m not sure that term makes justice.

So, heavily reworked tyre behaviour model, heavily reworked tyre heating model, heavily reworked tyre wear model all of them not just reworked values but with all new physics features, equations and data. On top of that we got reworked brake heating model… but more about all of this on a dedicated post about tyres and brakes.

Suspensions. We got completely new damper model. As you know dampers are usually simulated in sims with 4 values. Bump, rebound, fast bump and fast rebound. But… in ACC we know have full blown damper graphs. Obviously in the setup screen you guys have the usual clicks to work with, but under the surface, each click points to a different damper graph. Also, we have a completely new bumpstop system. The bumps have variable stiffness and variable ramp (graph) of their stiffness. That was actually a forced evolution of the physics, because otherwise it would be practically impossible to set properly the cars, because of the very advanced aerodynamic model… just as in real cars.

Which brings us to the aero model. Completely rewritten from scratch. This is not even an evolution, it’s a complete rewrite. Instead of creating various “wings” that each one of the generates a specific lift and drag around the car, as in AC and more or less all the simulators out there, ACC uses a new system that takes into account aeromaps from wind tunnels or CFD and applies lift and drag to the whole object as one. Doing so, it takes into account on how the object moves its aerodynamic pressure point forward or backwards depending on pitch and yaw. Before saying that this is something you can achieve with the “wings” model of AC, I can assure you it is different. The system actively moves the pressure point and can influence front or rear lift and drag, depending on what it happens in the car pitch rotation, wing angle and so on.


The end result, is a much more pitch sensitive aero platform with situations that force you to choose specific ride heights, wing angles and suspension settings to counteract the aero influence on the handling. Because of this, as in real life, maintaining the aero platform becomes crucial, ride heights are probably the most important part of the setup and bumpstops become extremely important to control the car.

The GT3 cars do heavy use of ABS and Traction Control systems, permitted by the rules. So for ACC we had to improve furthermore the ABS and TC systems. They have become quite more complex, taking into account much more information and telemetry inputs as well as having different behaviour and output result.

Obviously we also have a completely new weather system and dynamic track. The rain simulation is really a breakthrough and, modesty apart, I’m confident that you guys are going to be impressed by it. All hail Lord Kunos, he really did an astonishing work and of course I'll do my best to explain you all the various situations, simulation and techniques to get the best driving experience out of it.

TL;DR

So, I just wanted to give you a small taste of what I’m going to cover in more detail in the following days. I’ll try to write specific posts about tyres, suspensions, aerodynamics, TC and ABS, setup screen and strategy and weather simulation.

Once again, thank you for all the support you are giving us and we really hope you’re going to enjoy the initial early access releases. Looking forward to your feedback and to the more advanced releases in the next months, when ACC will really start to shine!

Using the undeniable talents of the team at Kunos, building on the lessons already well learnt from the original title, and with a nice and shiny new graphics engine to boot, ACC already looks to have the makings of a classic firmly wrapped up...

Assetto Corsa Competizione will be available to purchase on Steam Early Access from September 12th 2018.

Check out the Assetto Corsa Competizione here at RaceDepartment for the latest news and discussions regarding this exciting upcoming sim. We intend to host some quality League and Club Racing events as well as hosting some great community created mods (we hope!). Join in the discussion today.


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 Did you enjoy the new blog post from Aris? Looking forward to ACC? Do you think the game will improve on the original Assetto Corsa? Let us know in the comments section below!
 
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I agree no need to wait, I have reservations but I still ordering it

What does it matter what myself or anyone else thinks and why should it have any bearing on what you conclude

Remember we all have various driving styles, garage setups, controller settings, strength, preferred vehicles, circuits ....all these and more can have a direct impact on perception for each of us

Just the difference that 60Hz or 144Hz can make to feel and steering in some situations is not things others may readily understand

All these and more can have a varying impact on all of us ... ALL of US

The only thing matters is something feels right to you and you won't find that out waiting for others to tell you

P.S.
When I say rF2 is the best sim I have ever driven I have never thought for one second I was speaking for anyone but myself ;)
 
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My main issue with AC is the way the steering feels, it's not progressive like on a real car or even other sims, you spend most of time in either the 90° position or 0° (the best way i can describe it), th game makes you steer more than you would want, it's really part of AC's DNA and i hope it will be fixed in ACC (i have no idea what's causing it, but most likely it's tyre model related)

What do you mean not progressive? Unless you are using keyboard or gamepad to control your cars with like an on-off switch, all modern sims in the last ten years can be controlled or steered properly and easily with even the cheapest of steering wheels.
 
So wait, wasn't the tires supposed to be "perfect" in terms of behaviour already in AC? What are the changes? What results they produce compared to real life?

And what's with the aero and damper models being so advanced? Basically you are describing the good old rfactor1 models right there...

I got to hand it to you Aris, you are really good in creating hype, while not telling us much at all... why don't you make some Niels style videos instead, showing us the real graphs and data that you are using? You dont even need to show real one, just your approximations.
Nobody said that AC's tyre model was perfect, in fact I don't think you can say that about any simulator. Just because he doesn't get into more detail about the physics, doesn't mean they aren't detailed.
Maybe you could stop acting like a 10 year old. If you think AMS and Rfactor are so much better, you could use the time you wasted on this comment to go and play those.
 
Nobody said that AC's tyre model was perfect, in fact I don't think you can say that about any simulator. Just because he doesn't get into more detail about the physics, doesn't mean they aren't detailed.
Maybe you could stop acting like a 10 year old. If you think AMS and Rfactor are so much better, you could use the time you wasted on this comment to go and play those.

Are you offended? Did my stating of FACTS annoy you in any way? I don't need to "think" anything. I know the ISI engine inside out, and i KNOW what i am talking about because i mod it everyday. So why don't YOU go play AC instead of making a nonsensical reply to my comment...
 
I did my first track day this summer...no, that does not give me "F1 World Driver Champion" level cred, but I will say this anyways: no other sim comes close to replicating the feel of rubber under you butt the way AC does. After my track day experience, AC went from "one of my favorite sims" to just "my favorite sim".

I didn't head to the track expecting to have any one sim confirmed or rejected. All I can tell you is, about halfway through the session (after the initial rush of excitement/jitters had worn off) I was concentrating on a mid corner and an involuntary thought popped into my head clear as a bell: "holy crap, this feels just like AC!"

And this is no paid endorsement - I will be (gladly) forking over full price on 9/12 just like the rest of you degenerates! :p
 
lol.......no matter what the forum, subject or demographic. it always degenerates into some stupid argument by some elements, and an exercise in one-upmanship.

Whats the obsession with peoples insistence of attempting to "win" an argument on the internet?
Why do people insist on escalating things so quickly?
why do people get seemingly so offended by some typed words by a random stranger over a digital media...?

it must be exhausting trying to keep it all up. its certainly exhausting having to muddle through it everytime you scan a conversation.

EDIT: disagree..? how is this even disagreeable..? weird
 
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What do you mean not progressive? Unless you are using keyboard or gamepad to control your cars with like an on-off switch, all modern sims in the last ten years can be controlled or steered properly and easily with even the cheapest of steering wheels.

Ofcourse i have a steering wheel ... It's hard to explain because it's so obvious, the steering feels "springy" in AC, and that's why i said 0 or 90°.
 
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Are you offended? Did my stating of FACTS annoy you in any way? I don't need to "think" anything. I know the ISI engine inside out, and i KNOW what i am talking about because i mod it everyday. So why don't YOU go play AC instead of making a nonsensical reply to my comment...
Haha. It's funny that when people say "FACTS" in all caps they're always so smart and educated.
Who cares if you know the engine from ISI or from Grand Prix Legends? You're making assumptions about a game that hasn't even come out yet and claiming them as "FACTS" (again, in all caps).
I didn't get offended because you said rFactor's engine is superior to AC, you may be right, I don't give a rat's ass. It's just annoying that whenever I wanna see a thread about a game I'm excited about, someone has to behave like they're 10 years old and make comments like "The physics of the game I play are better than the physics of the games I don't play".
What's next? "My father is stronger than yours"?
 
lol.......no matter what the forum, subject or demographic. it always degenerates into some stupid argument by some elements, and an exercise in one-upmanship.

Whats the obsession with peoples insistence of attempting to "win" an argument on the internet?
Why do people insist on escalating things so quickly?
why do people get seemingly so offended by some typed words by a random stranger over a digital media...?

it must be exhausting trying to keep it all up. its certainly exhausting having to muddle through it everytime you scan a conversation.

Ah yes the science of internet trolls.
They often enter conversation to offer opinions of products or services that have nothing to do with the existing conversation with the target intention of starting a fight.
They look like this...
stock-vector-internet-troll-sitting-at-the-computer-vector-illustration-525954922.jpg


Back on topic, Assetto Corsa Competizione has been on my wishlist for months. This pricing structure is outstanding and I hope the sell 500K on day one. Thank you Kunos/505.
 
I don't know much about this new AC sim at all , but from that video , it looks really good. AC hasn't ever been my favorite sim to drive , but it seems this new one is quite a bit different in the physics , and it looks pretty damn awesome. Definitely be giving this one a shot.
 

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