Community Question: Should Racing Simulators Prioritise Soft-body Physics?

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BeamNG's class-leading damage model
Soft-body physics has always been a hot topic in the sim racing world, but which simulators could pull it off? What titles would it ruin?

Soft-body physics, or dynamics in the wider reaches of the technology, is a field of simulation that focuses on visually realistic physical simulations of the motion and properties of deformable objects or better known as 'Soft Bodies'.

The most common use of soft body physics within racing simulators is the damage model. Titles such as BeamNG.drive and its predecessor, Rigs of Rods, both show just how detailed and difficult the technology is to master. BeamNG has been in continual development since its release in 2013.

Pothole Damage.jpg

BeamNG's Soft-body damage model.

BeamNG is the obvious choice for a simulator in which soft-body physics works wonders. Without it, the project would have very little to write home about. But what current sim racing titles and projects would positively benefit from adding in a complex damage model that models both the visual and physical implications of damage realistically?

Could iRacing adopt soft-body physics?​

The sim with the best damage model is often considered to be iRacing, however, their damage model is still far from the level of BeamNG. The iRacing damage model is imposing until you start reaching the deeper levels of detail.

There are not too many chassis dents, just bodywork and mechanical damage that you can feel through your wheel - plus a myriad of parts flying off the cars, as well as wheels being visibly crooked or only hanging on by a tether if they take a solid hit. That being said, the iRacing damage model is certainly a class leader in the world of pure racing simulators currently.

iRacing's new catalogue-wide damage model as of June 2024

So would iRacing benefit from a BeamNG style of soft body physics? We do not think so. The newer damage model suits the simulator perfectly well. Despite lacking detail in some of the more intricate levels of damage detail, iRacing does a fantastic job of simulating what a racing crash looks like - something BeamNG often exaggerates and consequently falls down on.

Why Rally Is The Perfect Candidate​

If you have ever played the iconic rally title Richard Burns Rally, you will know jut how punishing a damage model for this discipline can be. However, modern iterations of rally titles have toned it down a bit when it comes to a comprehensive damage model.

Both DIRT Rally 1 and 2 had a satisfactory damage model with impactful mechanical damage and failures, however, some of the crashes that would have ended your rally at best simply require you to reverse and continue with a slight crack in the windscreen and a missing front bumper.

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Porsche 911, Dirt Rally 2.0. Image: Codemasters

EA Sports WRC
has this same problem. In small and medium-speed accidents, you are punished to a fairly high standard. If you clatter a wall, you will mostly likely damage your bodywork and maybe your suspension. However, a high-speed multi-rollover accident will more than likely not damage your car all that much, and certainly will not cost you a lot of time - even with hardcore damage enabled.

So is the world of rally crying out for soft-body physics? Let's take a short look into BeamNG'drive' s rally world to see if it could work.

BeamNG Rally 1.0​

BeamNG Rally has been created and published by Track Broseff on the BeamNG repository, and this mod breathes fresh new life into the title with custom rally stages on dirt and tarmac based on the real-world American Rally Association ruleset.

Rally Notes 1.jpg

BeamNG's rally pace notes

Over 88 miles/141 kilometres of rally stages are available, and all stages can also be run in reverse within the time trial menus. The maps range from Utah to Jungle Rock Island and everything in between. The real draw to this specific rally mod, however, is the inclusion of pace notes. A revolutionary addition that has put BeamNG on the map for rally fans.

Combine these essential rally additions with BeamNG's soft-body physics and you have a rally game that is as punishing and brutal as it can get in sim racing. Overall, it works brilliantly. The pace notes are mostly accurate with a few further additions that you will not see in any other games apart from Richard Burns Rally.

Should 'Realistic' Damage be the aim?​

But how about circuit racing? Often when the subject of damage models in sim racing is brought up, you will hear the take that the most realistic is the best. This is not always the case. Again, let's look at BeamNG. Your PC's required processing power to simulate your car is immense. Imagine trying to do that for twenty-plus cars simultaneously while also producing the driving physics and running an online server.

190E Merc Damage.jpg

Medium-speed wall impact damage in Automobilista 2

Most simulators skip a high-detail damage model in favour of a more immersive and detailed driving experience. This is not uncommon and is a tried and true method of creating an accurate racing simulation - it is the core of the experience, after all. Racing titles, especially pure simulators, should not entirely sacrifice their damage model; there is no question about it.

With that being said, accurately realistic damage should not be a priority for a lot of simulators. The relatively forgiving damage model of RaceRoom, for instance, could be considered a part of why the title can be run by lower-end PCs as well as forgiving small mistakes online, a key addition for teaching new players what is good and what is not without ending their race.

Which simulators do you think should include soft-body physics? Should it be kept to titles similar to BeamNG? Let us know in the comments below!
About author
Connor Minniss
Website Content Editor & Motorsport Photographer aiming to bring you the best of the best within the world of sim racing.

Comments

The object of the exercise, is not to wreck the car.
Any damage that does not influence performance with regard to the actual racing, is a waste of resources.
Body damage or deformation would require additional effort for physics mapping, just to be of any benefit.
Things like mechanical powertrain or transmission damage, flat tires, etc... are okay in simulation. You can pit for tires or manage short-shifting, gear-skipping etc..
All of that occurs in actual racing (with a performance deficit) wherein the driver is allowed to continue.
Severe body damage on the other hand...more often than not, would see the driver ushered off circuit once it was viewed by race officials.
The only place a driver would be allowed to keep a severely wrecked car on track is demolition derby.
 
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The iRacing movie is made at a typical rookie events around T1? ;)

It's great if cars get wrecked like in real life.
Many modern race cars are made from carbon parts that just need to detach or brake apart at some places.
That would work for me, don't think you need a full softbody physics model for that.
The crashes you encounter mostly last just a few seconds, you're part of the crash or you zip by and never look back. If it takes down the framerate with a full field down while it happens, rather not.
 
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The difference between Steel, Aluminium, Glass Fiber, Carbon fiber, they all react differently in an accident... are you gonna do them all, will the Marcos and Morgan still have Wooden chassis? to what point do you take the sim?
Will the next big thing be all moving parts take on their own physics, will the proshaft rip through the floor if the bolts sheer, the 10 kg flywheel smash through the soft cast ally bellhousing and make a bid for freedon across the fields at 6000RPM, it's great to be able to do stuff like that, but, I don't think it's really that important.

And as has been mentioned the object is to not damage the car in sim racing, I can understand that certain sections of the community (VR) might find it interesting to get out of the car and walk round...yeah, ok but that's like the grass and leaves on the trees... I don't care about that too much as I drive past at 90mph, I simply don't see it on my pancake screen... unless I'm upside down in a roadster!
 
Premium
Having raced in a couple of Sims in Online Multiplayer with other humans having some visual damage along with the usual tires / mechanical etc problems during a race may add to the realism, eg scrape a barrier wall which crumples the fender and bonnet along with the other problems....but would it make the online Sim a 'crashfest' having had this experience myself, ruining my Race:(

However, it would just slow down the Race if yellow flags keep coming out (eg. looking at IRL Nascar)...and of, course there is the new up and coming 'Wreckfest 2':thumbsup:.epic online wrecking, which is it's sole purpose:inlove:

From my own experience driving / racing around in BeamNG, I try not to crash knowing of the consequences
:confused:...well, for the most part:redface::roflmao:

0 BeamNG Gavril Cabstar ROLLBACK with WINCH copy.jpg
2 BeamNG Ibishu Signia RACE Fire copy.jpg
2 BeamNG Meo DRAG CRASHES Gavril BLUEBUCK and BARSTOW copy.jpg
3 BeamNG FAIRHAVEN Bluebuck & Burnside RAT RODS copy.jpg
5 BeamNG Gavril DYNAMO Barn Find at UTAH copy.jpg
5 BeamNG GRAND SCAVENGER at JOHNSON VALLEY copy.jpg


As to which other Sims should / maybe include 'Soft Body Damage' physics....the new 'ACEvo' would be the ground breaker as implementing 'SB' physics would require a ground up development with this in mind...only a personal opinion;)
 
There are lots of good reasons, and lots of bad reasons. For all the best reasons it doesn't have to be necessesarily super visually detailed. Just get things right how car object reacts to impacts, and how impacts deforms chassis (geometry) and body panels (aerodynamics). But nobody would appreciate that, extra negative thing to complain about, like 80% of other realistic things that will never be a priority. And if they will get there, it will be just for bragging rights: "it is there, yes we can, we simulate that", and the severity of unpleasant side of features will get nerfed till everybody has fun again. Everybody will live nice and happy lives and gradually get older happily with a lot of "woohoo, yes ! hihi. so fun !", the end.
 
For myself, the perfect sim should simulate all aspects of reality with 100% accuracy, but I can enable or disable any element within it as it's a sim, dependent on my desires / needs / mood at any given time.

My typical setup though is to keep damage visual only and no failures because I don't find fun in driving damaged vehicles or not being able to drive them at all. I get that damage systems encourage being more sensible and cautious, but that's not my style. Performing legendary sends and ascending driving beyond science into art is where the magic happens, and no damage model will trump that (for me). Besides, if you've done anything bad enough to warrant significant vehicle damage then you've likely already stuffed your race up anyway, hence why a restart button is always mapped to my wheel.

Maybe one day when we have one-to-one recreations of reality I might change my tune, but currently and ultimately, simracing is my happy place so anything that interferes with that is removed (because I can).
 
We have amazing driving physics, we don't need to innovate much further on that from where we are. We need to innovate in other areas now.
I couldn't agree less. You still can't hustle a car and be in control of it like you can in real life anywhere close in any sim like you can in Live For Speed and Netkar Pro (with the exception of some cars in AC but AC seems more vehicle/mod/content dependent relative to other sims, whereas every other sim is more core physics engine & core tyre model dependent). There's way too much odd, unnatural, "digital" behavior in most sims (but each in their own way/s) especially when near/at/over the limit.

Complexity of sims' core physics engines (including core tyre model) may have increased but that means nothing if the result of all those numbers - the final output - is no better (or at worse, worse).

Also, I could be wrong, but I don't think soft body physics necessarily only affects damage physics. You can probably implement it so it only affects damage but you can probably implement it in a deeper way. I bet if BeamNG suddenly removed all soft-body physics, it wouldn't simply be damage that changes but entire aspects of vehicle dynamics & kinematics (and therefore affecting all sorts of aspects of vehicle behavior).

If the question is talking purely about soft-body damage-only physics as opposed to overall soft-body physics, then I'd say, It'd be nice but there are other areas I'd look into improving way more (especially physics, audio, and FFB).

P.S. Just watched the first 45 secs of that iRacing video and most of the damage doesn't even look like soft-body physics, it's full of entire whole pieces of the car flying off like in non-soft-body physics games and barely any vehicle deformation. Looks more like standard physics with a bunch of fake particles flying everywhere for added effect. I've seen much better in iRacing videos (let alone other games).
 
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I like super realistic looking crashes, although they are not super necessary.

But I think sims should at least detach the broken parts and make them disappear. And simulate the outcome. I mean, you lose a rear wing, you lose the downforce on the rear. You lose the front wing, you lose downforce in the front. Geoff Crammond had it 30 yrs ago... It was said here that the objective of sim is not to crash. Sure, but crashes happen, it's part of racing and should be part of simracing.

iRacing made some progress in this area, but I hate how sometimes carbon fiber wings still get bent. Nonsense.

I find it even worse when sims have no visual damage at all. Recent DLC for RF2, for instance. Some old RF2 mods, like the URD LMP1, had very decent damage simulation. But then official content came out in which the cars have ridiculous small deformations all around the bodywork, even when you crash at 200mph and roll over for a mile and a half.
 
I think there's huge - ongoing - misundetstanding about what soft body physics is about @Connor Minniss :
Realistic damage is sort of a side-effect, what soft-body does is that id doesn't treat the whole car body as a solid obiect that lies on some indeformable structs with a spring+damper only allowing for vertical motion.
With soft body physics you are actually simulating a set of nodes, each with its weight, linked together by flexible links, each with its spring/damping depending on the simulated material.
Supercars go great lenghts to maximize body rigidity, and if you test an old muscle car against a new one in BeamNG you can really feel what body rigidity is all about.
Also suspensions end up being a lot more compliant since all of the structs and bushings are actually deforming, for offroading it makes a huge difference.
Also aero devices can and often do deform, that's again something that can naturally fall out from soft body.
Damage is the wrong reason to want soft body physics in a sim, you want it just because it is increasing realism in a lot of areas by that last "1%" that does a lot for the driving feel.

The difference between Steel, Aluminium, Glass Fiber, Carbon fiber, they all react differently in an accident... are you gonna do them all, will the Marcos and Morgan still have Wooden chassis? to what point do you take the sim?
Will the next big thing be all moving parts take on their own physics, will the proshaft rip through the floor if the bolts sheer, the 10 kg flywheel smash through the soft cast ally bellhousing and make a bid for freedon across the fields at 6000RPM, it's great to be able to do stuff like that, but, I don't think it's really that important.

And as has been mentioned the object is to not damage the car in sim racing, I can understand that certain sections of the community (VR) might find it interesting to get out of the car and walk round...yeah, ok but that's like the grass and leaves on the trees... I don't care about that too much as I drive past at 90mph, I simply don't see it on my pancake screen... unless I'm upside down in a roadster!
you don't need a huge quantity of parameters to simulate different materials properties, and BeamNG can already do all you say in the first half of the post. It's just a different approach to physics, you have to explicitly set a material for each moving or static part of the 3d model, then you find out how good that car is, while in standard sims you have a file containing a lot of guesstimated numbers that should reflect the 3d model but may not do at all.
It's the difference between simulating an object's measured properties (accuracy depends on data and only simulates what you tell it to) or modelling it with the right materials and then measure the resulting properties (accuracy depends on material simulation and model's geometrical accuracy, may have emerging properties like planes and boats working in beamNG, no other sim can do that).
 
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BTW, if you want I'd be happy to write down a tedious article trying to make a better explanation of both soft body and rigid body physics, and simulations in general, because I feel this is a topic where there's a lot of confusion in the sim racing community about how their favourite sims work under the hood.
 
Why is this even a question?

Yes they should prioritize physics at every opportunity...

But we aren't there technologically to really do everything well and have a race offline with AI... So I'm prepared to wait the decade or so for that to come in...

I can see both sides of the casual coin loving and hating this becoming a regular part of sim racing... Those who love to crash and those who don't like how that changes how the car handles will have 2 very different views...

Luckily to them it's just a game and they can turn those options off... I do hope developers start catering to the hardcore sim racer more with those same style of options in the driver aids so we can enjoy more pure simulated physics than we do currently...
 
BTW, if you want I'd be happy to write down a tedious article trying to make a better explanation of both soft body and rigid body physics, and simulations in general, because I feel this is a topic where there's a lot of confusion in the sim racing community about how their favourite sims work under the hood.
I'm all for it!
 
Depends what you want to simulate... I only have my toe somewhat in the water of how sims work "under the hood" but to use my usual framing, there's physics simulation, and there's story simulation. The goal of physics simulation is to match the real world behaviours of the physical system that is a car. The goal of story simulation is that when you describe what you did in the game, it matches the real world events. Features can be both - a common complaint in AC CSP chat is "I only want it to look like rain, I don't want the ground to be slippery". They want the story of driving in rain, but not the physics.

Soft body crash damage is in the story category - realistic values are unfortunately not really possible with current hardware. Even once they are, it is way too many unknowns to expect a realistic outcome. But that's not a problem if what you want is the story - "I crashed on the last lap and limped it across the line in 5th place" doesn't require the damage to be accurate, just that it follows causality (first you hit the wall, then you drive with a car that's worse)

Personally I think it'd be healthier for people to recognize that both of these are under the heading 'racing simulator' in the same way that Farm Simulator is a simulator, but as it is, if you put unrealistic physics in the simulator in order to produce stories, or to add features make the game worse if they were realistic (for example: realistic race starts, where you get in the car 45 minutes ahead and then sit in the pits and on the grid and so forth), people are gonna get mad that it's "not a simulator".
 
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I would love to have better soft body physics in racing games. I probably spent as much time in the 90's racing as I did going the wrong way, destroying my opponents.

That being said, It strikes me as a problem that hasn't been addressed because of resource allocation. It's 2024, and we're still debating the realistic behavior of a single component, tires, which is fundamental to the sim racing experience. If this problem hasn't been solved despite its higher salience and lesser complexity, I don't believe we'll see soft body physics addressed until there's a paradigm shift in game development. Even then, I think mechanical damage will be addressed in depth before physical damage.

Furthermore, if anything, in instances where games are licensed by manufacturers, there is probably a disincentive for damage to be realistically rendered.

In short, the return on investment is probably not worth it for game developers, much to my chagrin. The task is too big, and the reward is too small.
 

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