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Tanks - tracked vehicles driving and handling

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To repeat my question again -

On 2.5.2018 at 9:31 PM, x3kj said:

driveOnComponents and the other driveOn thing (i forgot) is also missing

Whats the purpose of those selections for tankX? Is it still important? First time it was introduced way back when, i think it was to help with climbing ability - which now technically is not necessary (propably?) because there is fake acceleration helper force.

What can we expect from these selections in terms of function and behaviour and what do we need to keep in mind when modelling the components? Are there specific things to avoid there?

 

 

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On 9/10/2018 at 4:02 AM, scotg said:

I'm always speaking from a mod perspective, so...
Was the neutral steer rate ever updated? Specifically, is there a setting to determine how fast a vehicle can turn in place, or disable it entirely? I'm thinking this might be the first step to making better half-tracks.

You can now use UVAnimations & carX simulation for some better representation of halftrucks. IFA3 is now using such approach ;)

 

7 hours ago, x3kj said:

Whats the purpose of those selections for tankX? Is it still important? First time it was introduced way back when, i think it was to help with climbing ability - which now technically is not necessary (propably?) because there is fake acceleration helper force.

What can we expect from these selections in terms of function and behaviour and what do we need to keep in mind when modelling the components? Are there specific things to avoid there?

It's still useful for tank bellies since when vehicle is colliding from the bottom with some obstacles (be it for example famous antitank wall which can be found in large quantities across Altis or Stratis), friction can be pretty high and vehicle might not be able climb over some obvious objects. Tracks also got some components in Geo PhysX due to fact that i.e. grenades are not colliding with PhysX wheels - it was disabled last year when we noticed grenades (or in general, any collision) could go quite deep into wheels and then engine would try to push it up in violent way.

 

https://imgur.com/a/G6KOv5f

 

 

For comparison, here are friction values extracted from config (they can be changed if someone wish to do so ;) )


	class PhysXMaterials
	{
		class PhysXMaterialBase
		{
			isDefault = 0;
			isAnisotropic = 0;
			restitution = 0.05;
			staticFriction = 0.75;
			dynamicFriction = 0.55;
		};
		class Default: PhysXMaterialBase
		{
			isDefault = 1;
			restitution = 0.05;
			staticFriction = 0.75;
			dynamicFriction = 0.55;
		};
		class Terrain: PhysXMaterialBase
		{
			restitution = 0.01;
			staticFriction = 0.6;
			dynamicFriction = 0.46;
		};
		class Wheel: PhysXMaterialBase
		{
			restitution = 0.05;
			staticFriction = 0.9;
			dynamicFriction = 0.68;
		};
		class DriveOn: PhysXMaterialBase
		{
			restitution = 0;
			staticFriction = 0.01;
			dynamicFriction = 0.007;
		};

 

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While testing my mod tank's speed, I noticed it was going faster in a turn than it would in a straight line. I don't have a speed boost available on my tank. I thought it might have something to do with one of the tire slip properties, but just a random guess. To see if this is just mine or a common issue, I tested the Bobcat and Sochor the same way. The Bc was doing the same thing as mine - turning about 5kph faster top speed than going straight, as long as I didn't use speed boost/max speed. The Sochor went too fast in a straight line and then rolled over before I could observe its turning speed. I don't know if any of this is supposed to happen or not. If not, what should I start tweaking in order to fix my tank?

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On 10/12/2018 at 5:58 PM, scotg said:

While testing my mod tank's speed, I noticed it was going faster in a turn than it would in a straight line. I don't have a speed boost available on my tank. I thought it might have something to do with one of the tire slip properties, but just a random guess. To see if this is just mine or a common issue, I tested the Bobcat and Sochor the same way. The Bc was doing the same thing as mine - turning about 5kph faster top speed than going straight, as long as I didn't use speed boost/max speed. The Sochor went too fast in a straight line and then rolled over before I could observe its turning speed. I don't know if any of this is supposed to happen or not. If not, what should I start tweaking in order to fix my tank?

You can notice similar behavior on the vanilla tanks too, especially with Nyx. It's a downsides of the tankTurnForce, especially when using higher forces. Try to use lower values or limit the force to lower angular speeds. Tire parameters come into play as well.  You may try lowering the lateral stiffness or having a relatively small friction near zero slip - to let the tank turn well even with lower tankTurnForce configured.

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On 14.10.2018 at 11:04 PM, oukej said:

You can notice similar behavior on the vanilla tanks too, especially with Nyx. It's a downsides of the tankTurnForce, especially when using higher forces. Try to use lower values or limit the force to lower angular speeds. Tire parameters come into play as well.  You may try lowering the lateral stiffness or having a relatively small friction near zero slip - to let the tank turn well even with lower tankTurnForce configured.

 

Sounds weird to me. Guess it needs a tiny fix, tanks in RL tend to slow down whenever steering actions triggered, 1st because most common method is to use breaks at the track of the side one wanna turn to. 2nd because turning causes higher mechanical resistance everywhere at tracks and wheels. You consider scotg's finding as worth to fix?

 

Quote

tankTurnForce

int>0, (PhysX)

How well a tank can turn, higher = better turning ability.

This is possibly some kind of coefficient that generates turning power for a TankX vehicle. The value apparently needs to be very high, on the order of 20-30 * vehicle weight (in kg) or more<?>.

[(comment in "Samples_F\Test_Tank_01\CfgVehicles.hpp"), A]

 

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20 hours ago, The Man Without Qualities said:

Sounds weird to me. Guess it needs a tiny fix, tanks in RL tend to slow down whenever steering actions triggered, 1st because most common method is to use breaks at the track of the side one wanna turn to. 2nd because turning causes higher mechanical resistance everywhere at tracks and wheels. You consider scotg's finding as worth to fix?

During the "overhaul" we've tried to have the tanks without the artificial turning force but it wasn't possible to achieve reasonable behavior so we had to resort back to this solution. Knowing and accepting the downside that you're mentioning.

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On 10/12/2018 at 5:58 PM, scotg said:

While testing my mod tank's speed, I noticed it was going faster in a turn than it would in a straight line.

An interesting effect, something similar shows up in Kerbal Space Program of all games...

They've got a number of rover wheels that behave like normal steerable wheels on a normal wheeled vehicle, then they have 1 beefy one with "tank type" steering - or rather, differential steering, without steering the wheel (its rotation plane is fixed in relation to the vehicles). It steers to the left by turning the right wheels more than the left and vice versa.

They were meant to be the slowest wheels in the game, but are in fact the fastest because they too accelerate in turns (it seems the outer wheels speed up without the inner ones slowing down), and rapidly giving left-right-left-right... inputs allows vehicles to accelerate to "crazy" speeds in a straight line (>100 m/s, or over 360 kmh... which is only crazy fast for rovers, since that game allows you to build things that reach speeds of several/dozens of km/second)

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It's a problem with any game that does not account for where forces used for steering come from. In particular, a "magic" speed increase on one side without either slowing down on the other or putting extra load on the engine. If this was accomplished by braking a wheel/thread instead, it would be better, but the vehicle would lose a lot of speed in turns (a serious problem with IRL systems that operate in this principle).

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On 17-10-2018 at 9:26 PM, The Man Without Qualities said:

Sounds weird to me. Guess it needs a tiny fix, tanks in RL tend to slow down whenever steering actions triggered, 1st because most common method is to use breaks at the track of the side one wanna turn to. 2nd because turning causes higher mechanical resistance everywhere at tracks and wheels. You consider scotg's finding as worth to fix?

Most common method for eastern bloc tanks, not western tanks.
Western tanks (literally since the centurion) use regenerative steering, where one track goes slower and that force gets applied to the other track making it go faster, basically little speed-loss or even none depending on what speed you're travelling.

This depends in what gear the tank is in too.

As most tanks have speed governors, they can't go above ~72kph, which is good because above those speeds you can't effectively turn.
One of the easiest tanks to drive is the Leopard 2 for instance, it drives much like a car would, generally considered to be the most pleasant and "accurate" tank to drive.
Soviet tanks don't have this, they have the typical one track brakes method.

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On 27.10.2018 at 1:56 AM, dragon01 said:

It's a problem with any game that does not account for where forces used for steering come from. In particular, a "magic" speed increase on one side without either slowing down on the other or putting extra load on the engine. If this was accomplished by braking a wheel/thread instead, it would be better, but the vehicle would lose a lot of speed in turns (a serious problem with IRL systems that operate in this principle).

 

2 hours ago, scavenjer said:

Most common method for eastern bloc tanks, not western tanks.
Western tanks (literally since the centurion) use regenerative steering, where one track goes slower and that force gets applied to the other track making it go faster, basically little speed-loss or even none depending on what speed you're travelling.

This depends in what gear the tank is in too.

As most tanks have speed governors, they can't go above ~72kph, which is good because above those speeds you can't effectively turn.
One of the easiest tanks to drive is the Leopard 2 for instance, it drives much like a car would, generally considered to be the most pleasant and "accurate" tank to drive.
Soviet tanks don't have this, they have the typical one track brakes method.

 

So I concur that in any case the vehicle would loose some speed, most old Russky-Tanks a lot, Leo-2 less.

Why is this working for wheeled simulation? When I turn there I loose speed.

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On 29-10-2018 at 2:24 PM, The Man Without Qualities said:

So I concur that in any case the vehicle would loose some speed, most old Russky-Tanks a lot, Leo-2 less.

Why is this working for wheeled simulation? When I turn there I loose speed.

Different properties/config most likely, from what I can tell, turning does reduce speed on MBTs, it just "bottoms" out at a certain speed.

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I'm a totally disgusted with tank driving .... what the hell are you guys actually doing about it ?  I've tried vanilla, I've tried modded and it is SHOCKING.  Here's some of the crap we have to deal with ....

 

Tanks veering off bloody straight roads for NO reason (makes no difference what combat status I set!),

 

Inability for tanks to turn on corner without crashing into anything

 

Tanks ACTUALLY SWERVE INTO civilians and their owns troops (W T absolute F !!)

 

Convoys?  Don't make me laugh !

 

Seriously devs .... I've lost all confidence in your ability to sort this stuff out.  As a long term supporter (right from the bloody start!) I'm disgusted in what we have to put up with.  Ignore your supporters at your business peril.

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I don't think this is limited to tracked vehicles. Wheeled vehicles do pretty much what you describe.

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I don't know how accurate this is, but I heard somewhere that the problem stems from AI-controlled tanks pathfinding as if they are infantry.

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On 4/3/2019 at 7:31 PM, target_practice said:

I don't know how accurate this is, but I heard somewhere that the problem stems from AI-controlled tanks pathfinding as if they are infantry.

 

Could be very possible. I've read they're afraid to touch it because it's a house of cards at this stage aka they're using 2001 OFP-era AI in 2013-2019 while they added tweaks systems, and other tech/complexity on top of it.

That's why 18 years later we're still talking about convoys, fighter jets that still dives or tracked&wheeled driving in general plus the new A3 issues because of said systems/complexity on the top of a relic AI. That's why A3 is more borked than A2 at the end of it's life.

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Playing IFA3 alot since im a huge fan and big supporter of IF, in their recent update, all the tanks are acting weird, now i posted some feedback on the release thread asking if anyone else

is getting weird behavior with the tank driving, and others are, but its not just IFA3 its vanilla game too!

 

What i been finding at least in IFA3 is I put down a Russian tank, give him a waypoint, and that waypoint is connected to a guard

waypoint, so the tank takes off but not at a normal speed but full speed!

 

Proceeds to the guard waypoint and once arrives, drives in a circle forever until some contact is made, Kju was saying it may

be something from the few previous updates to the game that has caused this but whats funny is the tanks were not doing this in the previous version of IFA3 so that

was February 14th, so a possibility that something with their configs, CUP terrains update, and the game itself did something to the AI.

 

I find it rather annoying that this is happening it sorta ruins that aspect of the game for me because anything remotely realistic

or at least trying to be realistic or immersive is thrown out the window.

 

Anyone else finding the tanks in the game doing this, and with other mods? i've only tested IFA3 so far.

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7 hours ago, krycek said:

 

Could be very possible. I've read they're afraid to touch it because it's a house of cards at this stage aka they're using 2001 OFP-era AI in 2013-2019 while they added tweaks systems, and other tech/complexity on top of it.

That's why 18 years later we're still talking about convoys, fighter jets that still dives or tracked&wheeled driving in general plus the new A3 issues because of said systems/complexity on the top of a relic AI. That's why A3 is more borked than A2 at the end of it's life.

Yeah that sounds about right. From what I've gathered, the original AI programmers left the (very complex) AI code in a poorly documented, rather spaghettified state which made it largely incomprehensible to later programmers.

This leads to current BIS members having to contrive half-working SQF-based solutions for most problems, as every time they try to venture into the dark and foreboding depths of the engine they risk triggering a proverbial cave in at the higher levels.

 

I have to assume that a major motivator for BIS developing a new engine is the fact that RV is at this point, as you describe, an overburdened, lopsided house of cards whose inner workings are held together by half-forgotten arcane magic.

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On 4/4/2019 at 2:01 AM, kremator said:

I'm a totally disgusted with tank driving .... what the hell are you guys actually doing about it ?

 

nothing, as has been the case for many years 🙂

 

not even allowed to disable or overwrite with our own systems, only layer on top.

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