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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This sounds very exciting, but I wish it could be applied back to AC. I will be disappointed to have to wait for x months or years for the new engine to be applied to a wider variety of cars and tracks than what we see announced so far. Blancpain is great, but I like a broader range of vehicles to test and race.

If Reiza could figure-out how to apply the UE to AMS, I'd be in heaven earlier :)

I'd rather seem them work on a smaller numbers of cars and tracks and do a good job than to see them spread themselves too thin and mess it up... like Project Cars...

Also, there's no reason why they cannot come up with some DLC content down the line. There are many GT series around the world...
 
  • Deleted member 113561

Rf2 might be great but they just don't sell it the proper way. And even if they do only gt3 it won't be on par with kunos projects
rFactor 2 needs to be finished first. A lot of bug fixes, polishing, finishing features and more official high quality content.
 
I did many seasons in the SRS with Assetto Corsa. Final season we ran full damage. My experience was that "full damage" was more like console sim damage, meaning "not much." I was mostly disappointed by this particular aspect of the game. If I buy it, it will only be for giggles, not serious sim racing.
I agree. I will not buy this game unless it improves its damage physics.
 
even at the young age of 56
At 62, you are young Buster! But age doesn't matter if we're young at heart. Hey how about a senior's league in RD?

I too am really looking forward to this and I hope with SRO licencing they expand to include Pirelli World Challenge and Blancpain Asia for additional skins, championships and tracks.
 
;)

By the way, are we taking bets about the time of Stefano's next public meltdown?

Hm... I for one actually (but I`ll never tell anyone, so schhhhh) find it quite human and fairly ok, that the spokesman of a company - ANY company, does not keep taking rants and raves up the tailpipe - but sometimes let´s enough be enough and responds accordingly. but that´s just MY opinion of course. Feel free to have another. :D
 
Very happy to know that the next real Assetto Corsa (AC2) will use those physics + all the future developments and improvements from ACC it's a very good thing and value. ACC may drain a portion of the original AC fans , i just hope Kunos have something to keep the rest of the AC community that have shown their lack of interest for ACC already ( road cars fans, drift fans, rally etc) hot for the next 2 years which can be long. AC is not just a game or a sim, it's a way of life, a habit, a sentimental link, peoples have found a way to include AC in their daily life like driving the Miata every Friday night, driving a lambourghini after watching the Grand Tour, recreating their own car and driving it on green hell,find friends online and build social habits, create mods etc... You cannot ask the community to change a deeply, good, installed habits...All company have to make "the mistake" during the growth process, i hope that ACC is not this "mistake" for Kunos because they may have some difficulty to recover.
 
Not my intention to start any war, but I find it funny... comparing the hype... will ACC have anything that rF2 don ´t have in terms of physics? People get so excited like all this is new, I mean, I´ll get it and drive it, but no need to get over excited?
 

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