Friction

Okay, it's about that time. I believe that the tops of cars, or anything that is not the tires, is too frictionless. It's as if the ground is ice when I'm sliding on the roof. I was wondering, is there a way to change the amount of friction something has?
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Also, would it be possible to change the friction of surfaces (different amounts of friction per texture) ?

 

Roofs are cars don't have that much friction watch this video.

 

There's a reason why we don't use aluminium or steel as tires.

 

I agree but also think there's a lack of friction in tires as well. For example, in almost any real life scenario, drifting off the side of the road into the dirt should result in tires digging into the surface and flipping the car. Never happens in beamng. The vehicle will just glide along the terrain. And like you said, a car sliding on its roof will do so for an impossibly long time.

 

The physics engine will struggle to simulate that, as this game is already at it's FPS limits.
It'll cause lag and all that stuff.
The tire friction in this game is pretty much as good as it'll get with modern technology at the moment.
And solid grooveless Aluminium or steel is not a grippy surface, it will slide along the ground for some time.

 

Each map can have a "depth map" which can make dirt deep, and which can in fact, make the car flip / rapidly slow down.

rFactor 2

 

I meant the detailed ingame way of flipping the car over.
I've tried the mud trick and it almost never works.
It's only ever worked with sand for me.

 

Which are both simulated using the same system, just different settings.

 

and that requires terrain deformation.

 

I dont know if this is for all cars but the tire pressure on the ones i can recall is 28 psi (about 1.9 bar, around here we usually run at 2.2-2.4 bar on road tires), whereas the table below shows the actual numbers for track day-applications (Track/R-tires, road tires should be even higher?).

Now, most cars in Beamng should be Heavy or Very heavy class so that makes me think that all the tires run abit too low pressure in Beamng, making tire friction off?

 

Low pressure will increase grip at the cost of decreased tire response if anything.
What you mentioned with dirt happens because dirt in BeamNG is treated as merely a surface with a different (lower) friction coefficient, rather than a bunch of loose organic and mineral particles as it is in reality. So cars just slide more on dirt, rather than digging in.

IIRC, before the update that gave tires different grip coefficients for dirt and asphalt, dirt was more grippy than regular tarmac, which was highly unreallistic so it was changed.

 

What about make dirt and other non-solid surfaces a random pattern of grip value. Or maybe some kind of mesh holes that would grab the tire enough that it eventually flip the car while sliding but didn't slow us down that much driving over it.

Is it possible to code in what direction tire is moving on the dirt so there would apply more and more grip until it lost connection to the surface or change direction?

 

Most times when a car slides off the road it will not flip. I am not really sure where this idea is coming from... granted I also don't know how fast you are driving when you think this should be happening.

Usually (unless you slide sideways into a sand or gravel pit with a LOT of speed, narrow tires, and a medium to high center of gravity) when a vehicle leaves the road (I am going to make the assumption that you are sliding sideways to get this flip started... like you were drifting and just took a corner a little to fast) the only time a tire will "dig in" to the ground and catapult it up into the air is if the ground is rather rough... Ironically, the higher the speed, the rougher the ground has to be to catch a wheel to start the tumble rather then just popping it into the air and nothing happening. If you add grass into the mix, then you need an even rougher surface, because grass can act as a bit of a lubricant under tires.



On rolling greens covered in grass... there is practically 0 chance that car will ever flip no way no how.

Usually when cars flip when they slide off the road is if the tire gets caught by something that imposes a large amount of force to the tire in question. That can happen by sliding into a small ditch, an uneven embankment, or... just something to impose enough force to either pop the tire, or deform it enough so that the rim hits the ground... once the rim hits the ground... well... that's just an entirely different ball game altogether.

If the rim hits the ground and digs in, still assuming you are sliding, then it will act like a shovel. That rim will dig under the ground and hold fast. That sudden stop is what will, in turn, punt the car over onto its side... not the tire itself.



In this video, right away, we get an almost perfect example of this. The ground drops away from the edge of the road a bit, so when the car goes off of it, the force of the falling car slams the rear tire and rim into the ground. This causes the tire to blow and the rim to dig in... the rest is history.

On that topic though... this topic originally started with the friction of cars sliding along on their roofs. The car in the video provided by someone else earlier shows a car sliding down the road with almost no friction at all, while the car in the video I just posted shows a car tumbling and tumbling and tumbling... so... what gives?

Well... the answer there is how the two cars are constructed mostly (where, how, and onto what, they flipped are also big factors, but I just want to point this out first). The first car in that video posted before looked to be a bog standard everyday automobile... Its designed to deform just like any other car. The car in the video I posted was a beefed up rally car. It is equipped with a roll cage. Normal cars, when flopped down onto their roofs, will just collapse... the more modern the car, the less likely it is to collapse usually, but even still... it will collapse. This then, in turn lowers the center of gravity and gives the car a much wider footprint to keep itself stable, so if the car didn't have too much rotational energy going into the roll, it will just sit on its roof and slide. A car with a roll cage on the other hand does not collapse (well... it's not supposed too... if it does then they did a bad job making it). This means that the car can hold a much rounder shape, keeps its center of gravity much higher, and in turn, burns off the kinetic energy by rolling over and over and over again.

Yes, in gentle enough rolls, both cars can stay on their roofs, and with enough energy, both cars can tumble... it highly depends on a lot of other variables then that... but, as you can see... different situations will have different results.

BeamNG simulates all of this already. There are no adjustments that need to be made to the cars of the physics engine... mostly, you just need to mess up in the right way, just like real life, to get these results to happen... the most unrealistic thing about BeamNG in this scenario to get these things to happen isn't so much the physics engine... but the fact that almost every road in the game is just a sticker on the flat ground. That means that when you do slide off the road, you have a nice, smooth transition... no sudden forces, just a slide onto a different ground type. As you can see in that RR video I posted above, literally nothing will happen in situations like that. It practically doesn't even matter how fast your going.

If the roads had a little bit if height to them (most roads around here are 4 to 6 inches higher than the ground around them... some even more than that) then I would be willing to bet you would see exactly what you would expect to see when a car slides off the road. The car drops, the rims dig in, and the car goes over.

 

Devs, please fix the friction. It feels like tires in beamng are made out of ice cubes and in situations where the car should obviously roll over it doesn't. I would blame the suspension, the cars don't lean how they should in sharp turns, leaving the car's center of gravity unchanged and unable to roll over.

 

I realize all of that, I had to adjust my cockpit fov to get better sense of the speed but I am sure cars just slide all over the place at 60km/h.

 

I would like to add... The tires side walls need a higher friction/bounce than the treads for a role over crash to work. Since a tire can not rotate sideways, it bites/grips surfaces when impacting at any reasonable speed. Every blue moon I see a roll over flip happen but it had nothing to do with the tires catching the surface. Like other poster said, its like they are ice cubes gliding along. I would like the Crashtest Dummies and Stiggy to have less friction so they can be ejected or thrown out of a car. They seem to stick to interior rather than slip out like a limp body should.