Interaction with the ground

[bkthunder]

Following up on the discussion started in this thread https://forums.eagle.ru/showthread.php?t=248457, I believe this is a more general DCS discussion so here it goes:

 

 

Why do we need "sticky tires" in DCS?

Most airplanes need unrealistically high amounts of thrust to start rolling (and keep rolling) on the ground in DCS, unlike what happens in real life where little thrust is needed to start rolling, and then the airplane will keep going at idle. Many airplanes such as the F-16, F-14 and Harrier IRL start rolling forward on their own at idle, F-14s would even shut down one engine when lightly loaded, in order not to gain too much speed during taxi!

 

 

And then again, the DCS MiG-29 doesn't have these problems, you can start moving with very little thrust and it will just keep rolling at idle for a very long time, as expected. It doesn't slide around with wind, the landing roll is perfectly reasonable. It's realistic!

 

 

So my question is, why don't we see the same (IMO excellent) ground interaction modelled in the MiG-29, on all other modules?

Was some new tech developed for the MiG-29 that is being implemented/tested only there?

Will these improvements become available for other modules?

 

Thanks

[Kid18120]

I'm guessing it all comes down to older FM not being reworked to accomodate new tech (A10C for example has an older FM compared to the MIG29's) and newer FM still not including such tech (i.e. F18 ).

I think ED will standardize all of their FMs to include the same major tech developments but this will indeed take lots of time and work, plus it's probably not high on the list of things to do right now

Edited August 28, 2019 by Kid18120
Fixed typos

[shagrat]

My guess it is depending on carrier ops or not. On the moving carriers the planes tend to slide and crash into each other especially in Multiplayer. The heavier friction seems to be related (Harrier, Tomcat, Hornet, Su-33).

If this is deliberate to fix the deck sliding, they need to find a solution for that, before changing the "stickyness" of the tires.

[Harker]

My F-18 doesn't slide on the carrier at all. I think a lot of people get theirs to slide by turning on NWS HI with a high speed and dragging the front wheel.

Other than that, I think it's a MP issue, since you have different objects (aircraft + carrier) that interact with each other and there might be inconsistencies regarding server sync with that.

AFAIK, Hornets taxi around the carrier deck on idle or almost on idle, to avoid blasting people around in the cramped deck IRL. We certainly can't do that in DCS right now.

[shagrat]

My F-18 doesn't slide on the carrier at all. I think a lot of people get theirs to slide by turning on NWS HI with a high speed and dragging the front wheel.

Other than that, I think it's a MP issue, since you have different objects (aircraft + carrier) that interact with each other and there might be inconsistencies regarding server sync with that.

AFAIK, Hornets taxi around the carrier deck on idle or almost on idle, to avoid blasting people around in the cramped deck IRL. We certainly can't do that in DCS right now.

The point was that due to higher friction/wheel sticking the carrier aircraft, currently do not slide anymore (and I mean sideways slowly creeping into other planes).

[Harker]

The point was that due to higher friction/wheel sticking the carrier aircraft, currently do not slide anymore (and I mean sideways slowly creeping into other planes).

Ok, I thought you meant they were harder to control and sliding while taxiing. Did it happen in SP as well? I don't remember.

Still, making the wheels sticky is not the correct way to address that problem. They're not supposed to slide forwards and backwards, just roll. I guess it comes down to how taxiing actually happens in the game. Does the 3D model simply move forward as a whole and the wheels turning is just an animation effect based on the speed? Or do the wheels actually make contact with the ground, really turn and thus are responsible for the aircraft moving, like IRL? And is the thrust generated by the turbines and the inertia actually the reasons for the movement or is it tied to other stuff in the sim? The fact that it looks real doesn't mean that it's simulated like the real thing (I'm not saying it isn't, I don't know how it's programmed).

Edited August 28, 2019 by Harker

[shagrat]

Ok, I thought you meant they were harder to control and sliding while taxiing. Did it happen in SP as well? I don't remember.

Still, making the wheels sticky is not the correct way to address that problem. They're not supposed to slide forwards and backwards anyway, just roll.

Single player was the same, but usually you rarely hit AI planes. MP was messy, as sliding sideways closer to your wingman and the tiniest lag (warping half a meter) usually happened seconds before alignment was finished, or the moment you wanted to taxi... I hope there is a way to fix the exaggerated friction and still fix the sideways sliding with wind and ship movenent. :)

[NineLine]

Ok, I thought you meant they were harder to control and sliding while taxiing. Did it happen in SP as well? I don't remember.

Still, making the wheels sticky is not the correct way to address that problem. They're not supposed to slide forwards and backwards anyway, just roll.

 

As far as carrier concerns its not a matter of how the tires interact with the carrier deck, or how real it is, its simulating a non-moving aircraft on a moving platform. Sounds easier than it is. Its why when we started seeing the Hornet, you would see all sorts of weird things with the Hornet on the deck of a moving carrier. The current solution is certain RPM holds the aircraft in place, and higher than that frees it up.

 

This is also why we see an issue with helos sliding on the deck, because their RPM is always much higher on startup, so they are loose faster.

 

And again, the MP bouncing is somehow related to carrier starts and airfield landings in many cases.

 

SO I think most of this is still a WIP, and trying to figure out what works and what doesn't.

 

Edit: this is all reported by the way, I should add.

[Harker]

Single player was the same, but usually you rarely hit AI planes. MP was messy, as sliding sideways closer to your wingman and the tiniest lag (warping half a meter) usually happened seconds before alignment was finished, or the moment you wanted to taxi... I hope there is a way to fix the exaggerated friction and still fix the sideways sliding with wind and ship movenent. :)

Yeah, I figured it'd be more of a problem in MP. I don't know how much can ED do here, since it's very dependent on the client's connection to the server, which is out of ED's hands. Sounds like an inherent limitation of the MP scene in general. DCS is certainly not the only game that has issues like this.

[Harker]

As far as carrier concerns its not a matter of how the tires interact with the carrier deck, or how real it is, its simulating a non-moving aircraft on a moving platform. Sounds easier than it is. Its why when we started seeing the Hornet, you would see all sorts of weird things with the Hornet on the deck of a moving carrier. The current solution is certain RPM holds the aircraft in place, and higher than that frees it up.

 

This is also why we see an issue with helos sliding on the deck, because their RPM is always much higher on startup, so they are loose faster.

 

And again, the MP bouncing is somehow related to carrier starts and airfield landings in many cases.

 

SO I think most of this is still a WIP, and trying to figure out what works and what doesn't.

 

Edit: this is all reported by the way, I should add.

 

Thanks for clearing some stuff up. I know it's not easy, since you have to "couple" two different entities in the game world and synchronize their respective movements. Add MP desync or lag, which ED can only do so much about and the issues are understandable. I don't know enough to say what could be done about it, if anything.

I think the RPM limit solution might be OK, but what about using generated thrust, with a limit tied either to the aircraft type or the weight? It might be easier to deal with, for future projects.

[bkthunder]

My guess it is depending on carrier ops or not. On the moving carriers the planes tend to slide and crash into each other especially in Multiplayer. The heavier friction seems to be related (Harrier, Tomcat, Hornet, Su-33).

If this is deliberate to fix the deck sliding, they need to find a solution for that, before changing the "stickyness" of the tires.

 

Understand this is an -albeit non-optimal - solution to carrier sliding, but the problem exists on ground based moduels as well: F-15, Mirage, F-5, F-86 etc.

 

Really, the only one that behaves correctly is the MiG-29.

[bkthunder]

As far as carrier concerns its not a matter of how the tires interact with the carrier deck, or how real it is, its simulating a non-moving aircraft on a moving platform. Sounds easier than it is. Its why when we started seeing the Hornet, you would see all sorts of weird things with the Hornet on the deck of a moving carrier. The current solution is certain RPM holds the aircraft in place, and higher than that frees it up.

 

This is also why we see an issue with helos sliding on the deck, because their RPM is always much higher on startup, so they are loose faster.

 

And again, the MP bouncing is somehow related to carrier starts and airfield landings in many cases.

 

SO I think most of this is still a WIP, and trying to figure out what works and what doesn't.

 

Edit: this is all reported by the way, I should add.

 

Thanks for the insight on the RPM thing, it's interesting / nice to know how things work on a sim level.