Large maps and vehicles

Hey devs,

As we know, people have created huge maps since BeamNG.drive made its initial debut in 2013 or so, but one thing I always noticed, especially when you are going far away from the center of the map, your vehicle starts to wobble. At first, you can only notice it in the interior. But if you continue driving further you notice that the vehicle also starts to visually do that on the exterior...

Why is this happening? Is this a solvable thing? And is this the primary reason why you do not make official maps larger than the ones in-game? Just a pure question out of curiosity.

Cheers,
Gregory U.

 

I'm not a dev, but I believe the issue you're having is related to floating point inconsistencies at extremely high distances from the origin (0,0).
If you really want to push this, spawn a car underneath smallgrid and let it fall overnight. When you look at it in the morning it will be an absolute shaking mess.

 

It is not really an issue, and yes I have done that before and you are right about the shaking mess.

 

I never have had that happen before. Ever. never even heard of this. you must like exploring huge maps all the way out the the very edges .
That is really interesting, though.

 

(Minor Bump)

 

What Nadeox1 said entirely.

I am the maker of Roane County TN USA. This map was only supposed to be a TEST, with just some AI-enabled roads, a terrain (an ugly one at that, look at the very first post I made of it, it was hideous).
It was only supposed to be a proof-of-concept that it 'could be done' and was. *cries* THEY MADE ME FINISH IT! *cries a whole huge, very wide river slowing down the simulation terribly to 3fps*
You asked for it you got it.

Floating point physics only handles so many digits. When you get so far from the center, the coordinates increase, rounding off the least digits in the number.
It's fine say (random example) if you're at 500.1234, 500.5678, 1.xxxx in XYZ coordinates.
Get to say 10,000.xxxx , 10,000.xxxx , 1.xxxx (assuming same height vertical, you've just traveled north-east for random example), and you start dropping those small digits of .xxxx, which, doesn't really happen when those coordinates are smaller, but does when they're larger (such as near the edges of Roane County). This is FLOATING point math, or ROUNDED, fast math. A FLOAT is a ROUNDED, easy to process number. It's approximate, not perfect. It works normally as within the game's initial design, with stock maps and vehicles.
However, if this was a space simulator, it would be much different, as witnessed on one space map we had many moons back (last fall?).

Sure, we could alleviate SOME of that, but the math would be inherently 10x slower, or be forced to use the ALU (arithmetic logic unit, VS floating point unit (FPU) which Beamng.drive now uses). The ALU is used when you need a perfect number every time (calculator), but for physics, etc, the FPU is used. The FPU is also used in many game's AI routines and for physics in many other games, like water physics simulators and such.
The FPU is a purposed-built DSP essentially right inside of EACH of your CPU's cores, and has been such since the 486 DX-class of processors.
The SUPER NINTENDO (Super Famicom in Japan and similar countries), had an FPU in some of the games, notably, Starfox, Stunt Race FX, Dirt Trax FX, Vortex, and even Doom port on SNES. If you walk up very close to a wall in the first room, of the first level of Doom, on the SNES, you will see the texture 'wiggle' much in the same effect the objects and cars have an inch of wiggle room in Roane County's more outlying areas. It's due to the FLOAT sums created by using a non-precise floating point method of math. When it needs to be done now, and isn't mission critical, the FPU is a great solution, and has been used in gaming since the days of DOOM, in fact, the next evolution of the Doom engine, Quake, also by iD software, required a pentium-class FPU to be present, or it wouldn't run at all!

So yes, this in a nutshell, is why you get the shakes as if you're engine's vacuum lines have popped loose on a 4 cylinder engine (blast you, 1993 Ford Escort!). It does NOTHING detrimental to the physics or results of them, it's only visual. It's come up many times (dozens and dozens!) in my Roane County TN discussion thread, and few know it better than me, as the map project is OVER TWO YEARS OLD now. I am working on it today yet. The shakes are here to stay, unless maybe processors get 10x faster (and there's a sequel to this game in the future, possibly) or idiots like me stop teasing huge maps that dwarf most AAA-class games. Yes, Roane County is bigger than GTA, but it's the physics in this game that make it 'better'. Sure there isn't as many clear-cut goals (I am only one person), there's no guns (yay!), no violence (except car accidents, what an exception), but you can do whatever you want, whenever you want, as you please or see fit.

So, don't worry, it's not you, it's not your PC being "stupid technology", nothing's broken, and nothing will break because of it (unless maybe you don't maintain/clean your PC regularly), it's just the side-effect of the Floating numbers. You're seeing rounding done by modern cpu's, that's all. It's nothing new, it's just only more visible now. The closer you are to map center, the less it will do it (it won't do it all when you're just SE of Rockwood in Roane County, as that's map center).

So rest assured, and just try not to notice it. It's not noticeable if you're in motion at any decent speed.

--Cheers!

P.s. This FPU-requirement is also why AMD FX and older APU's (non-Ryzen) processors stink at Beamng.drive and multiple cars!

 

Hey all,

Well, uh, okay...

I did know it wasn't just me or my AMD FX-9590 PC being stupid technology, I just wanted to know as to why that was happening. Now I know why, so thanks for that explanation! So that is one two questions answered, now the other one.

Is this the primary reason why you do not make official maps larger than the ones in-game?

Thanks @bob.blunderton.

Cheers,
Gregory U.

 

Sorry for the 10 day late reply here.
I make decent effort in making maps from 6km x 6km to 22km x 22km (smallest being Nevada Interstate or Tail of The Dragon, largest being Roane County TN USA, with So-Cal Interstate somewhere in-between in size).
The physics get rough any larger than say a 15 x 15km map-size. They get downright shaky above 20~25km map-width (so basically, more than 12~15km from the center of the world coordinates 0,0,0, and you will see it quite clearly when stopped, anything over 6km and you will see minor vibrations when stopped). It's due to the current computer technology, only rounded approximations of math will be fast enough to be used (floating point, floating means rounded) for a real-time simulation.
I don't make 'official maps' because the developers haven't hired me on. I'd love to, but that's their game and I don't have professional tools beyond a few low-priced ones (like my terrain generator L3DT program), that I have bought, and whatever is Open-Source. That and I can't figure out Blender 3d to save my hide (sorry, I text-edit my models as needed).

Thanks for the compliments though - cheers!
Let me know if you have any other questions.

 

Oh, that's interesting. That gets me wondering as to why the vehicles in games like American Truck Simulator and Euro Truck Simulator 2 do not shake like in BeamNG. Do they use a different algorithm like APU?

 

Other games either move the 0,0,0 with the player (this is hard to explain, but it hasn't been done since games of old DOS days), or they don't use floating point physics to the degree that BeamNG does.
APU is a term for CPU (main processing chip in PC) & GPU (graphics processing chip) all combined into one chip, sometimes even (albeit wrongly) called a SOC (system on a chip) especially if it has sound capabilities, and network capabilities built-in (then it's right).

ALU is Arithmetic Logic Unit. This does precise mission-critical math.
FPU is Floating Point Unit. This is used for super-fast bulk math during physics simulations. It doesn't have to be mission critical - accurate yes - but there's an amount of 'float' or 'approximation' built into it.

ATS (American Truck Stimulator), doesn't use Floating Point Math for the physics, that I know of. IT does however support tiled terrain, something that BeamNG is yet to support - hopefully one day (it is on the road-map) they will support it too. That is how they easily added in 'filler' sections to make the routes longer, as the game was far too compact to be realistic before. If you look closely enough, you can sometimes see where the terrains meet in it.

Physics computations per-second per game:
GTAV: A few dozen physics points on a car 20 times a second.
BeamNG: Hundreds of data nodes and beams, 2000 times a second.

I hope I've answered your questions, but if you have more, I will do my best to make sense of it all for you.

--Cheers!

 

Wait, so tiled terrain is on the roadmap for BeamNG.drive? Could you please tell me more about this?

Sorry, I meant ALU, not APU.

 

Tiled terrain, the ability to have more than one 4k x 4k (at the largest) terrain in the game at the same time, and have collision on all the terrains (currently, you can have more than one terrain but only the first one will have collision, game limitation).
So yeah, that'd be nice for larger, or at-least more detailed maps. It is on the road-map and dev plans for the game, or at-least it was when i last checked. I don't know how it will affect FPS though. Will sure be useful for Roane County. Currently Roane county uses ONE large terrain, when I scale it to tiled terrain, it will use 16 terrains for four times the ground resolution for X and Y independently (it may end up being more, actually).

 

So essentially, if what you are saying is actually going to happen, we could see maps like West Coast, USA, and Utah become larger? That means that the tunnel loop in Utah could be removed and lead to a new tile. And the island that's West of Belasco City could then potentially have its own tile and the island will be filled with suburban housing or a national park. And the interstate just east of Belasco City will extend out to maybe even some other city or even cities. Then I think the chance that Belasco City will expand southwards also exists. These are just my theories. @Nadeox1 is tiled terrain actually on the roadmap for BeamNG.drive?