Incorrect AWD behavior

[Unster 371]

As mentioned in the news sub-forum, the current AWD behavior is incorrect (when diff lock is off).  All the wheels act like they are connected to one open differential.  For example on a 6x6 if one rear wheel is in the air, that's the only wheel that will spin.  In reality, at least one of the front wheels would also be spinning.

Edited December 17, 2020 by Unster

[Eversman 63]

I guess this really depends on the truck an it´s differential setup. should be reviewed for every truck.

[Unster 371]

5 hours ago, Eversman said:

I guess this really depends on the truck an it´s differential setup. should be reviewed for every truck.

I doubt this kind of setup exists in real life.  I don't think it's even possible, and even if it was, it would be quite useless, since you'd end up with all the torque going to one wheel in some situations, completely defeating the purpose of AWD.

[Unster 371]

This is still incorrect in 1.7.0.  I still see just 1 wheel spinning with AWD on after traction is lost.  There should be at least one wheel in the front and one wheel in the back spinning.

[rarum 32]

I checked 1.7 - no changes in physics. Only new items not related to truck and physics was added. Simulation model was not changed. I think the only one guy working on physics was fired.

[XenoRad 13]

This has been brought up on the Discord channel as well. Yes, AWD is not exactly functioning as it should. The short of it is that there was not enough time to further change this before the new DLC and patch.

Whether or how much this will change in the future is still anyone's guess but I see two main solutions:

1. Simple solution, when in AWD and diff-lock off the game makes sure that each differential gets at minimum 10-15% power at all times, regardless of how many wheels are in the air. With AWD and diff-lock engaged the power percentage gets equally distributed among all differentials. Such a setting could be used for all trucks with multiple driven axles and will prevent all power going to a spinning wheel in AWD.

2. More complicated, truck accurate solution. In AWD each differential will received somewhere between 0-50% power depending on the actual setup. Differentials which take power one through another (think the two rear diffs on the B-131) should always be locked together, whereas differentials powered separately from a central transfer case (think C-255) can have this vary.

Not knowing the internal code this could be easier said than done. I would prefer option 2 however and I'm thinking that if a template can be configured for one truck then it should be relatively easy to adapt to the others.

[Unster 371]

Well, AWD used to work correctly in the older versions of ST, so there's really no reason to overthink it.  I do like the more open differentials in the current version, but AWD was broken in the process (when diff lock is off).

[XenoRad 13]

1 hour ago, Unster said:

Well, AWD used to work correctly in the older versions of ST, so there's really no reason to overthink it.  I do like the more open differentials in the current version, but AWD was broken in the process (when diff lock is off).

I used to think so too, but recently I fired up the legacy Build 2015-01-02 and while it did take more effort eventually I did manage to spin only one rear wheel while all of the others staid put in the rear 4x4 configuration. I can't remember how it behaved with 6x6 but it wasn't fully realistic before either.

In any case, now we have a good basis to build upon. For me the mud is behaving properly so if the power transfer with AWD and diff-lock is improved then we're set.

[Unster 371]

OK, I don't think I ever tried that legacy.  I meant versions 1.5 and earlier, though it may have been the same as the legacy.  I never noticed just one wheel spinning with AWD, but I wasn't trying to get it either.  With the current system it's very easy to get one wheel spinning.

The mud is good, but with the stock settings too easy to be realistic considering the depth of the mud.  IMO, it's a lot closer to reality with these settings in media.xml:

            PushResistance="0.25"
            SubstanceFriction="0.4"

[oldman777 122]

I fixed media.xml suitable for all types of transport, incl SHERP and completely suits me:

	<Mud>
        <Substance
            FullPushDepth="1.2"
            LinResistance="0.75"
            PushResistance="1.0"
            SubstanceFriction="4.0"
        />
    </Mud>

 

Edited December 18, 2020 by oldman777

[Unster 371]

The game probably should have different mud traction for casual & hardcore.  Hardcore should be 100% realistic, otherwise you might as well not even have different game modes.  I prefer to have 100% realistic mud and then adjust the maps to where they are playable but still challenging.  I don't like this insane mud that you can drive through easily as if you have a magical super truck.

[oldman777 122]

Everything in the game should be magical, unlike real life.

[Unster 371]

3 hours ago, oldman777 said:

Everything in the game should be magical, unlike real life.

Sure, if you're playing a fantasy game or some arcade racer.  This is supposed to be simulation.

[oldman777 122]

17 hours ago, Unster said:

Sure, if you're playing a fantasy game or some arcade racer.  This is supposed to be simulation.

The game will always remain a game, in any mode.

[Unster 371]

@oldman777Of course it's a game.  But it is also a simulation (to some extent), which is a type of games.  I don't have a problem with player assists, as long as they're optional, for people wanting an easier experience.  But there should also be a full realism option for things that matter, like mud traction.