F86 AI Damage Model

[Boomer20]

Now I know the AI damage model/Flight model is a bit of a mysterious but I felt like mentioning this.

1v1 Dogfighting with an F86 in a Mig15. I shot the tail off as shown in the picture. Still manoeuvres no issue. Maybe slightly less turn rate that's all. Later get behind and pump those 37mms into the back and the result damage is what you can see in the picture. Smoking engine and no ailerons. Having fought a lot of WWII AI I've noticed that the DM improvements meant that normally once the engine starts smoking that bad it won't last long and eventually gives out. The Sabre however kept going, kept manoeuvring, kept doing those gravity defying stall turns and super accelerations even with most of its control surfaces gone. And the engine never died. He just kept going. At least as a positive his turn rate was terrible without the ailerons.

[Eviscerador]

I'm not saying that the current damage model is OK. BUT:

- Destroying the rudder has no effect on turn rate, only on lateral stability.

- What you got ware flaps, not ailerons.

- Considering the white and black smoke, most likely it was leaking fuel or hydraulic fluid and had a damaged engine. Most of the time when you get an AI that way it will shut down the engine in few minutes.

- If you said his roll rate was terrible, then what you got probably was the hydraulic system (hence the white smoke)

 

Can the AI damage models be wonky from time to time? Yeah, the damage model is designed to interact with missiles mainly. We all expect that with the new damage model they are going to introduce in the warbirds, everything will improve.

[Squiffy]

LOL! Maybe I should buy the MiG and enjoy some pounding firepower...to little effect. Haha just kidding. Yes the AI seems wonky and all the points above are on target. It's almost as if the AI was designed to make you mad, and not be a worthy adversary. That's why we always hear about flying online. That's all well and good, but I don't want to "go out in public" and spoil for a fight without practicing. That gets to another psychological point where some involved in the community, coders or online "vultures," get their kicks out of sticking it noobs and rookies. What the heck ever happened to sportsmanship and honor? Ah well, I'm ranting (as usual haha). The AI will eventually punch out with that much damage but the unbelievability of it is obvious. Talk about an immersion kill.

[msalama]

and all the points above are on target

 

At least the one where he claimed to have shot both ailerons out was not, since the AI aircraft in the picture still has them attached.

[Boomer20]

Thanks for the response guys.

 

I'm not saying that the current damage model is OK. BUT:

- Destroying the rudder has no effect on turn rate, only on lateral stability.

- What you got ware flaps, not ailerons.

- Considering the white and black smoke, most likely it was leaking fuel or hydraulic fluid and had a damaged engine. Most of the time when you get an AI that way it will shut down the engine in few minutes.

- If you said his roll rate was terrible, then what you got probably was the hydraulic system (hence the white smoke)

 

- It would be nice if there was some sort of way to show that lateral instability with the lack of rudder in the AI. Particularly in those hard stall turns where I assume you need to kick the rudder to nose over. The effect on turn rate was just something I noticed happens, at least its a positive over the old turn it into swiss cheese and it acts like nothing has hit it.

- :doh: All I've been making mission for and flying lately is the Sabre so you would think I would have noticed that. I've put shame on my 20 odd years of love of flight.

- I was expecting the engine to shut down in a few minutes and it did not, I was surprised. Maybe was just a one off and I was impatient and didn't wait long enough. Shame I was careless with my ammo and forget I was flying an interceptor that doesn't have a huge amount.

- If thats actually how they've modelled it, that's a nice touch and good to see. I wonder if the AI can run out of Hydraulic fluid? When I've lost hydraulics in the Sabre it didn't take long to lose most control, was still flyable to a point but not quick as good as the good old AI buddies.

[Squiffy]

Correct mslama. Gotta be careful with the word "all" although I did mean in the post above, not all the posts ;)

Edited April 25, 2019 by Squiffy

[Squiffy]

Hmm, I'm curious now, just how different is the AI FM from Player? In both jets and props, the torque and roll instability at low airspeed is challenging and realistic AFAIK. But then the AI is not and we see the example here. When scissoring against AI, you struggle with control "reversal" and coordination to execute a nice S while the AI seems air show perfect even while smoking and punched full of holes. Maybe a wobble can be created for the AI so at a certain level of damage a random or programmed wobble happens to simulate damaged systems? It's probably the simplification of the AI FM that causes this but it would be nice to now how.

[Boomer20]

Well for starters the AI FM is an SFM. For me the issue seems to fall on the instant acceleration and deceleration in near level flight meaning they almost never overshoot you and if they do they go into that endless climb to get away. The other one I've noticed is there super tight turning circles, certain AI aircraft are worse than others (looking at the spitfire, mustang, mig15, f86 and F5 here) and while sometimes you can still outturn them usually your starting to black out, I've even gone to F2 when this has happened to see the AI pulling a tighter turn than me and they are pulling like 4g will I'm around 7.

Now like all Flight Simmers I know all the solutions to how to fix these :P (not including just be a better pilot) but given that I'm no coder or software engineer and I have no idea how the SFM are DM or AI for that matter are coding there's zero point in me stating how to fix that.

[Squiffy]

In Microsoft Combat Flight Sim 3, the FM had two files for players. Not sure about AI. There was a database of parameters kinda like the aircraft.lua and then there was the actual FM file which was a bit more tricky with a dedicated .exe editor to generate the code. But it was built with an interface like a database with fields for the aeronautical figures. It also had model hard point, contact, and damage box info. My deepest dive into this stuff was with the Spitfire MkV add on. MS Silverlight was way cool and we built 3 additional theaters for that game! 4 counting WWI. The tail wheel was so dang weak that you could break it easily taxiing on grass. It was a huge immersion kill. Seriously it was a stupid low break point at like 2 pounds or some nonsense. Once I kicked it up to reasonable force levels given aircraft and pilot, it was better. I also built grass airfield facilities with many files to render it in game. A big one was the airstrip surface data where the hardness was controlled to make concrete different from grass. We used this to allow a softer but not plowed field death level grass aerodromes for the BOB early mod. I also created a Sikorsky R-4 helicopter flight model based on the Storch STOL FM. Using wind, you could hover and land. It was very cool. My dad worked on them in the Air Corps after WWII and earned his GI bill for college. He was an engineering professor for 35 years and is still kicking, reading FlyPast magazine at 91 years! :D

[Boomer20]

I'd love to explore tinkering with the AI for my own private use, maybe with mods (custom AI aircraft etc) but I don't know if you can with official modules though. But again you gotta know what your doing and I don't.

[Eviscerador]

AI planes all have SFM (Simple Flight Model) That means they fly like in space, with little to worry about aerodynamics and engine restrictions.

 

That is the reason most of the time you can't out manouver the same AI plane as yours, except when the AI skill is set to normal levels. He just have much more energy than you.

[Boomer20]

Yes I am quite aware of the UFO that is the AI SFM, I would have thought though that being an SFM and with the scripted occurrences such as stalling which is what you experience when flying an SFM that it would be easier to manipulate the flight model so its a bit more reasonable and less alien. Such as directly tinkering with the turn rate, acceleration etc. on specific aircraft.

[msalama]

All DCS aircraft have a bunch of SFM Lua scripts in their module directories. You can always make copies of them, edit, and reinstall with JSGME or some such to see if it makes a difference. Never tried this myself though so no idea how it'd turn out...

 

Please report back if you decide to give it a go however. :thumbup:

[Boomer20]

I had a quick look and I can see the values and all (I have tinkered with flight models for an older space game before so have a basic understanding of editing in notepad). Where's the best place to find any documentation or is it a wing it and see how it goes kinda thing?

[msalama]

Documentation? No idea. The files contain aerophysical and mechanical quantities that may be hard to find in a finished, off-the-shelf form for the AC types in question. You'll probably have to do some calculus, or just wing it and do some trial and error. I'd do the latter myself.

[Boomer20]

No quick tinkering I'm afraid, I was hoping that maybe there would be a defined stall speed parameter (like with max speed at sea level, altitude etc.) but there is not. And not knowing anything about calculating aerodynamics making trail and erroring a specific part hard. I guess though that's why its trail and error.

[msalama]

But couldn't you just make it simple and put something in there, test and rinse & repeat as necessary? And if nothing sensible comes of it, no harm done.

[Squiffy]

Aha, so SFM means Simple Flight Model. I was wondering about that. Is that the file mentioned above? I would love to look at that. I can look at the .lua files tonight. Gotta do laundry and wasted a couple hours this weekend experimenting with the P-51 50 cal sounds. No benefit in my mind so I switched them back. I just wanted a little my bang and boom at arms length rather than the pepper shaker sound we have now. But hey there are the sound settings in game too, "hear like helmet" and so on. I can play with that too.

Edited April 29, 2019 by Squiffy

[Boomer20]

Yes the SFM values can be found in the .lua files. There's hard values for AI max speed, altitude, + and - Gs etc. and then there's the SFM aero data and SFM engine data. Interpreting isn't easy. Particularly when you only want to tinker with certain aspects of the flight profile.

[Squiffy]

Thanks Boomer. I've started into it. You can see in my g suit thread. The takeoff velocities are the same. Wing loadings will be different which is great and should be that way. That's part of the MiGs advantage there. But the AI Hornet > 1:1 thrust ratio climb tactic is one of the nuts we want to crack. Or, we could tweak the Sabre like with the guns. I will try and do some testing but eyestrain is creeping in. I will be home on medical leave after a procedure next week so maybe I can try more then. ;)

[Boomer20]

As far as my understanding of the Mig-15 goes it was a bit of a rocket ship when it came to climbing. It was designed to intercept how altitude bombers after all. My personal gripe is the basic lack of a stall speed. However I have been getting good results by reducing the AI skill level to good. While they still maintain there gravity-defying qualities they are at least a bit more reasonable to dogfight with. Even making the odd mistake (decision) leaving them vulnerable for the kill.

[Squiffy]

Right. I feel the same. Just a couple nights ago I made the mistake of leaving an aircraft set to good and not average! Haha, Shows you where I'm at. I may increase the stall speed just to see how AI handles it. It could climb yes, but the maneuvering near the limit is what we'd like to tweak. I need to be careful because eye strain is cramping me up this week. I need new glasses but I have to wait until after my surgery next week. ;)

[Squiffy]

I have played with the SFMs. They are nice matrices with various data points set according to mach number. Roll rate and pitch rate were the first I tried at low speed entries for the scissor maneuver I was talking about. It can be done and can be blended across the matrix. Max g in turns, max angle of bank appear elsewhere but can be used to limit performance. It's working I am tweaking my beta install after the update. the damage effects are pretty cool with the smoke and shrapnel from good hits. Also, the Sabre must have higher M2 (M3) 50 cal shell velocity closer to 899 m/s. Extend life of round out to 10 units and maximum range to about 2000 m. Looks much more realistic and you can get hits on migs in higher speed distance shots with more g as it should be. And then when you close in like in a stall turn maneuver, you can shred them with accurate fire in less than 300 ft. Like you should with a 50 cal. The barrel heat dynamics are an exact copy of the Mig 15 cannon barrel. How is that possible? I have edited that down but they are different guns with different shells and the iron and tin probably came from different mines ;)

Edited June 17, 2019 by Squiffy

[Squiffy]

Check this thread for MiG-15 SFM edits

 

https://forums.eagle.ru/showpost.php?p=3954635&postcount=22

[Squiffy]

Just an update. I spoke to my brother who is an aerospace engineer for NASA and Lockheed Martin (not that it's a difficult question)...

 

When Mach = 0.0, Lift or Stall/Departure angle = 0.0

 

So the last number in the SFM for the MiG-15, top row, should be 0.0 and not 1.1 or some number less than that. At Mach 0.0 you are completely ballistic and not generating lift. You are stationary even. Yes this is the coefficient of lift and not the lift itself, but below stall speed, it is essentially 0. This is a problem. The matrix should shrink as you approach stall speed. In the stock SFM it does not. I tweaked mine and can check on that. Thought of this over the weekend on my visit home and sharing DCS videos with my dad.

Edited October 16, 2019 by Squiffy