Assetto Corsa: what free mods are out there?

little P

Super Mod
http://acmods.net/tracks/ebisu/

+

http://acmods.net/cars/nissan-180sx-type-x/

= :D

I love drifting, and the 180SX here has various different engine options (including a 2JZ option - booyaa) so it's a lot of fun drifting round Ebisu with the G29. A clutch pedal really makes a difference.

Assetto Corsa is definitely my go to driving game for authenticity. For me Project Cars ahs it beat in terms of looks and features (weather etc.) but it still has very arcade style handling whereas Assetto Corsa feels real. I'm going to get shot to peices but for me Assetto Corsa feels much more like driving a real car than iRacing or indeed anything else.
 
E

ElektroVodka

http://acmods.net/tracks/ebisu/

+

http://acmods.net/cars/nissan-180sx-type-x/

= :D

I love drifting, and the 180SX here has various different engine options (including a 2JZ option - booyaa) so it's a lot of fun drifting round Ebisu with the G29. A clutch pedal really makes a difference.

Assetto Corsa is definitely my go to driving game for authenticity. For me Project Cars ahs it beat in terms of looks and features (weather etc.) but it still has very arcade style handling whereas Assetto Corsa feels real. I'm going to get shot to peices but for me Assetto Corsa feels much more like driving a real car than iRacing or indeed anything else.

P's progress.
7c2214ccdb9f5df53106478cd20af931.jpg
 

Daunt

MLG Pro
I'm going to get shot to peices but for me Assetto Corsa feels much more like driving a real car than iRacing or indeed anything else.
I like to take the high road in this argument and say it may or may not have better handling, but iRacing's best features are not how realistic the cars feel (even though most of the time is feels real to me). It is unbeaten in a competitive, realistic racing atmosphere with cars and tracks that are second to none in accuracy and attention to detail.

On no other service can you consistently find open racing with drivers that are as serious and competitive as you, almost true to a real world racing experience.
 

Kenadian

Staff member
Site Admin
I'm going to get shot to peices but for me Assetto Corsa feels much more like driving a real car than iRacing or indeed anything else.
I don't know why anyone would shoot you to pieces for this, in fact I'd agree in some cases such as the Astons baseline. It feels like you're on a carrousel unless you add a ton of Traction Control.

I think after spending a lot of time in iRacing though the cars just feel more weighty to me than in Assetto Corsa. I think what Assetto Corsa has is better immersion from a visual and sound design standpoint but for driving I'd take iRacing over anything else.

...except on Grass then all bets are off.
 

little P

Super Mod
I like to take the high road in this argument and say it may or may not have better handling, but iRacing's best features are not how realistic the cars feel (even though most of the time is feels real to me). It is unbeaten in a competitive, realistic racing atmosphere with cars and tracks that are second to none in accuracy and attention to detail.

On no other service can you consistently find open racing with drivers that are as serious and competitive as you, almost true to a real world racing experience.
Yup, never in doubt iRacing has the crown when it comes to online racing and the way it's run (which you would expect for the amount of money you have to throw at it btw...). But, if you want a pure track day experience then Assetto Corsa has everything beat hands down. Something I like doing at the moment is taking a car (from the standard selection or any car you desire thanks to the free mods which are incredibly realistic) and running at the Nordschleife Touristenfahrten just for the sheer joy of trying to master said car around the green hell. Assetto Corsa's driving model is just awesome, and coupled with the Logitech G29 and H shifter with clutch, and Track IR I really do feel like I'm there. For much less money and much less risk of losing your house due to tapping a barrier...

But, that's the beauty of pc gaming eh, there's always a title out there that will suit your needs. I own Project Cars, Assetto Corsa, Dirt Rally, and spent some time in iRacing too among many others and they are all a master of one thing. There isn't one driving sim out there that covers everything, and nor would I want there to be really. Competition is only a good thing for us enthusiasts and there's enough room in this particular category for multiple titles.
 

Jeeve79

Casual
Funny how discussion changed to what is a good sim or not, and how no one mentioned Rfactor.

Iracing is being used by real professional drivers to prepare for races or learn tracks.
Rfactor2 evolved out of a GMOTOR iteration of Rfactor1 and is used by racing teams to train their drivers and setups like for example F1 Red Bull Racing, but there are many more.

IMO : Rfactor2 and Iracing are the only real sims. I believe Game Stockcar Extreme is also but it is another GMotor so falls under Rfactor category for me. There is a niche sim called LFS (Live for Speed) developped by 3 guys but it has fictional cars and tracks, no brands, no mods. These are the sims and these feel like real cars on real tracks. I like Rfactor because of its direct and visceral forces.
(i do agree that these sims are not looking that great, RF does not even have DX11, its DX9 !) But sims are about physics and forces.

Assetta Corsa on the other hand is NOT a true hardcore SIM. It has major setup issues. (Toe in out, brake pedal force, realtime tire info...)
The forces feel a bit more lame and less direct.
This does not mean it is a bad game, some cars feel very good.
Where AC lacks in racing pedigree, it makes up for in street cars. Sounds and visuals are stunning.
If u are a modder, u want your cars to shine in AC. They just look 10 times better then Rfactor. So if u feel like Iracing and RF lack in visual fidelity and u just want to have a fun drive in all sort of cars and mods and tracks, u go AC.
U want hardcore racing? U drive RF and Iracing. So u can have the best of both worlds. I dont drive Iracing, personally it is too expensive and no mods. Dont drive Pcars cause it just feels wrong and i hate it, got my money back and some piece of the annual profits.
Conclusion: If u are on tight budget and want open mod community, u go RF and AC. These have terrible pickup races and no ingame league system, u need to engage in leagues yourself by going on internet and forums. If u dont feel like doing that and want to have good quality ingame league system, and more money, u drive Iracing. Any way u look at it AC is cheap, looks and sounds great, and u can have loads of fun with it, and host races yourself with port forwarding.
This might be a bit complicated for some but it is not a "mission impossible". The host server thingy in AC could have been better but it defo works and it is a lot of fun. I keep going back to it to try new cars and tracks with friends so AC gets the job done. Some cars have never looked better on a pc then in AC.
Dont take my word for it but i have been simracing more then 15 years so i guess that couonts for something.
It went like this: GPL, Papy Nascar 2003, GT Legends, RF1, LFS, RF2, AC.
 

Daunt

MLG Pro
Here's a great, interesting write up ( I love reading more into computer science) about why iRacing is a bit limited graphics wise, and also an indepth at what goes on in first-person sims.

[HR][/HR]

Michael Kopack wrote:
Ok, let's see if I can educate the non-technical/non-computer science folks here a bit...

First my credentials - Undergrad in Computer Science from Georgia Tech, specializing in Networking, graphics, and computer hardware. Masters in Computer Science from Drexel University, specializing in AI and graphics. I currently work in a research lab doing Robotics systems research and engineering. So, I have a LITTLE background in this stuff...

Now, first off, I've seen some people try to compare iRacing (or any first person simulator, as this would apply to Flight Sims, driving sims, etc) to other games and claim it looks and feels "old". NOTHING could be farther from the truth!!! The graphics might not be quite as flashy as other driving games that came along later, or as amazing as stuff like Call of Duty or other FPS games, but that is VERY much an apples to oranges comparison as there is so much under the hood that is different about how each game works.

Let's try to explain what I mean by that... Let's do a quick inventory (and I'm sure this isn't exhaustive) of everything that goes into iRacing (and this is only covering what goes on while actually racing):

* read inputs from controls (wheel/keyboard)
* read data from network from other players
* calculate all physics (note, for iRacing this is a REALLY big one - it's what sets them apart from most others)
* based on physics and inputs, calculate where your car now is
* send out network data to tell everyone else where you are
* draw all the graphics - note that it has to do multiple renderings to deal with the mirrors...
* play sounds (either continuing the sound that was playing in the last cycle, or change it to a new sound, and in reality it's mixing multiple sounds together on the fly...)
* whatever else they do...

Now, we've been told that iRacing does all this on a 60Hz cycle (60 times a second), or 16ms. Ok, let's think about that - they do all that work in less time than it takes to blink your eyes. And they try to do that consistently not on a console gaming system where they know exactly what hardware they have to work with, where the first one off the assembly line performs exactly the same as the last one, but rather on a mish-mash of CPUs, GPUs, drivers, Operating systems, and 3rd party software running in the background. Why does that matter? Think about it - They have to make the system scale such that things like the physics and the network still happens to the same level of fidelity even if the CPU you have is quite a bit slower than the high end ones some folks have. 16ms is 16ms - if your CPU is super fast, maybe it can do more operations in that 16ms, but they can't rely upon that.

Now, that would be all well and good if your computer was ONLY running iRacing so that all that CPU power was only thrown at iRacing. But it's not. Instead your computer is often doing a ton of different things, and so it's swapping tasks giving each of them a little time on the CPU and then pausing them and moving them off and something else on. Again, that wouldn't be that bad if it was done in a deterministic reliable way (like on a Real Time Operating System like VxWorks... Windows typically is NOT). In a real time OS, you set up a schedule for all the tasks and you are guaranteed to get service on that schedule - so you can say "this thread requires 50ms every 1second" and you will get it no matter what. In something like Windows, that doesn't happen - you get a slice but it's not guaranteed how long it's going to be, and it can be preempted (kicked off the CPU) if the CPU needs to service something with higher priority, like a DMA request. So again, you get little bits of time on the CPU, yet you still have to do all this work. For simplicity sake, let's say windows has a bog simple round robin process scheduler - Where every task is set up on a big circle and each task gets say 2ms time and then the CPU moves on to the next task... the more tasks you have the longer it takes before your task gets onto the CPU again. (In reality this is NOT how it works, the scheduler instead does things like take priority into account, and task priority escalation so low priority tasks don't get completely starved of the CPU). So every time you run another thing in the background, that's less time iRacing is getting the CPU - again, if you have a multi-core CPU, that might not be as big a deal because those other tasks might get put onto other cores, but if they don't, they're stealing time iRacing needs. As a result, iRacing needs to build in some "buffer" time into their loop - They try to keep all their work to around 14ms vs use the full 16ms, otherwise if they get bumped by some other process, they can usually still complete all their work within the 16 ms window. (For example, say iRacing uses 14ms of the 16ms window, they might get 3 ms of the CPU, then get swapped out for some other processes for 1ms, then get back on the CPU for 5ms, then swapped out for another process for .5ms, then back on for the last 6ms... iRacing's 14ms is completed, other processes used up 1.5ms, and so the combined completed in 15.5ms which is < 16ms, so they achieved the goal, hurrah! No stuttering! If, however, that other process that ate .5ms had eaten 1.5ms, boom, they overran their schedule by .5ms and you get some stuttering.

"What about splitting it up into threads though? We have all these cores now, let's use them!" you ask... Sure, BUT, not all problems are easy to split up to run at the same time... For instance, can you brush your teeth, while eating, while cooking the food, while loading the dishwasher? No, you have to sequence things because the output of one step (cooking the food) is needed before you can do the next (eat the food)... Maybe you can do some other tasks (that aren't interrelated) like talking on the phone while eating or cooking, but you can't do everything that way. This is VERY much the problem for a realtime simulation like iRacing - you need the data from the network update before you do the physics calculations. You need the Physics calculations before you can determine your car's new position. You need the car's position before you can report the position, you need all of those before you can render the graphics. Some things like the sound can be largely managed in their own thread with inputs from other threads (like the physics and position data so it knows what engine sound to play). When you look at those things that must be done in sequence because of data dependencies, that becomes your critical path in the code - the software can't go any faster than that path runs. So if you're trying to optimize, you need to do it in that path to make things go faster.

Why can some games make more use of more cores? Because what they do in their main loop has less dependencies. Maybe they don't have to wait on network data (ie, single player games), or maybe the physics doesn't have to do multi-body interactions 3 levels deep, and instead of of single depth (player to environment, but not environment to environment) and so they can do more things across multiple threads because the interactions don't require the threads to wait on each other for data. Or consider a game like Civilization - turn based strategy. The ONLY hard dependency on time they have in something like that is on the animation of units moving on the map - they have a TON of AI for each of the computer players, but those operate independently of each other, so those can be done in different threads, and they can say "Come up with the best answer you can in 5 seconds" or they could say "run until you come up with an optimum answer, no matter how long it takes" - again, they don't have a time constraint like iRacing has on how fast the application must update. Realtime Strategy games like Starcraft have SOME timing constraints and so they use the "AI thread - calculate the best answer you can in x ms time" approach, or they use AI algorithms where they can start operating on a partial solution while continuing to calculate the best solution piecemeal on each cycle through the loop. (I had to write a derivative of the A* path planner algorithm to work like this for the game engine I built in grad school).

For example - Let's say we have a situation where the player throws a ball at a stack of boxes. In a complex simulation like iRacing, not only does the physics have to calculate the interactions between the ball and the boxes, but also interactions between the boxes and the boxes and the ground. The more boxes you have the more interactions you have to calculate. Since you are doing box to box interactions, you need to determine the effect of one box as it is falling with that of another box so they "tumble off each other" realistically, which means you need to know where the first box went before determining where the 2nd or 3rd or 4th, etc. The more boxes, the more complex the calculations, the longer it takes to perform, and you can't split it up because even if you did, you'd have one thread blocking waiting on the output of another thread, which effectively turns your threaded attempt at parallelism into a single threaded linear process.

As somebody else said, addition of the particle effects in this season's code introduced hundred or thousands of additional calculations that need to be factored into the physics.


Many games choose the fantasy path, they cannot do the math. Thats why they are not able to do a good or bad driving racecar, they all drive the same if you like. They do feelings .


Bingo - other "games" focus their available CPU cycles on less calculations and thus have more free cycles to devote to flashier graphics or AI (which somewhat can be offloaded to other threads, but not always) etc.


Some have claimed that iRacing should throw everything out and start over - I can understand why people say that, but the fact is, when you design a game engine you make certain decisions based on certain design factors - how much physics, what kind of physics do we want to support, do we want online or offline play, AI or real players, how many cars should we support, how big/detailed do we want the map/tracks to be, etc. If they go in with the same answers to these questions, they're going to probably end up with very similar design decisions as the current engine was based on. That's going to yield very similar results. But with a new code base, you also get all new potentials for bugs - bugs that they probably already have long since killed in the current code base, but since you wanted them to throw everything out, they can come back. Worse, you could end up with a whole new set of bugs you haven't seen before because of interactions in the code you didn't have currently that can be an utter headache to track down and kill.

So what they are doing (refactoring and optimizing specific sections at a time) is the RIGHT approach. The ONLY time you go back and start over is if you want to change the decisions upon which the system was designed to factor in some new idea or maybe go from single player to multiplayer, or change how the physics work, etc. iRacing has largely made the right decisions in their design, and they've adapted over time as new features are desired or new concepts are realized.

Is it certainly easier at times to just start fresh - you can maybe find new ways to organize and architect things to break dependencies and rearrange stuff, but on something the size of the iRacing code base, doing that is NOT feasible. Not unless you all want iRacing to stop doing ANY development on this current engine (no bug fixes, enhancements, etc) and instead want to wait 3+ years for the team to build a whole new engine and simulation. I don't think any of us wants that.

I've had to do this sort of thing before - take an existing system that, while it worked and we thought it was well architected for the problem at hand, it had some limitations in it, and rebuild it from the ground up... And it was a nightmare - while I was able to factor in new ideas that allowed for a much more flexible and higher performing system and fix a lot of the limitations of the original system design, it introduced a whole NEW set of headaches and limitations and bugs that had to be dealt with.

Starting over from scratch is NOT a magic bullet solution, it takes a LOT of time to do, and introduces a whole new set of issues to deal with.

Do I think there eventually will be an iRacing 2.0? Sure, but not without a LOT more $$$ flowing in for them to make the investment to redesign and rebuild. It would end up being a very different animal than what we have today. And honestly, while there have been some issues, particularly with this season's code because of their attempt to fix some of the limitations of the original back end architecture, it is far from a "non-working, bug ridden system"

I personally am looking forward to what the DX11 update brings us in terms of performance and the opportunity for the iRacing staff to get back some CPU cycles in the main thread (that 16ms critical path loop) so they can use them for new and exciting things. DX12 (eventually) could be an even bigger improvement, but to achieve it will require another major investment by iRacing to support things like Vulkan.

Anyhow, I hope this helps clear up some stuff to those who are less computer/software savvy so they have a bit more of a clue when complaining about iRacing...
 

little P

Super Mod
blah blah blah We're off to Barbados with yo moneyz and you can carry on playing iPotato.

Nah seriously it's an interesting read, but smacks a little of "we don't want to rock the boat". It's an interesting situation for sure for them. It's obvious though that the service is what comes first, the graphics/sounds are a distant second for them eh. The fact remains though it looks very old now, and it's such a shame we can't have a combination of iRacing's service and Assetto Corsa's visuals/sounds, with Project Cars weather and day/night cycle. Now that would be some game. Oh and Rockets of course.
 

Jeeve79

Casual
Quote: I personally am looking forward to what the DX11 update brings us in terms of performance


I hope they do this for RF2 (praying to the simgods)
 

little P

Super Mod
I'm impressed with the update. This I can race with. I haven't found a way to eliminate aliasing yet though. The "shimmering" lines are distracting. I've tried bumping the resolution right up to 4k AAx8 but they are still there.
 
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