Aircraft Toughness

[ShrikeHawk 384]

Can anyone explain what determines an aircraft's toughness? I've got a Bf-110C that I've been fiddling with. Presently, it takes roughly 350 hits (NOT just shots fired - 350 Hits) with .303 rounds to bring it down. That means flying in close and pounding away accurately for a long time. That seems outrageous to me. I've reduced the "MassFraction" and  "StructuralFactor" on a number of systems and it's still very tough to bring this bird down.

 

I've done things like this:

 

[LeftWing]

//MassFraction=0.15
MassFraction=0.09
//StructuralFactor=1.5
StructuralFactor=1.1

 

I've only had very moderate success fiddling with them.

 

Is there something else I should look at?

[+baffmeister 1,205]

One of the big problems I had with the BoB FM's I've worked on was getting the Browning machine guns to work against the Luftwaffe aircraft. I ended up harmonizing the guns a bit to concentrate the hitting power. It wasn't done in a scientific fashion, I just angled in the Spit and Hurri wing guns one half degree. It helped quite a bit. I also increased the aim accuracy for the AI and increased the burst length a bit, as well as reducing the firing distance. It's enough that the AI can occaisionally "flame" a Luftwaffe bomber and the bombers have some armor protection. The other area to look at is min/max extents, fuel tank positions and things like that. Lot's of the old models are really messed up in that regard. Every BoB FM I've done has had the Min/Max extents modified using Fastcargos' ruler tool. It worked quite well but now I get to do them all again using Mues' Lod viewer which is a big help and something you should look into.

[Gatling20 753]

Structural factor is the number you are looking for. Jack it up to 2 or 3 and you will have a very tough target, especially for small-calibre bullets like the .303.

I find I can easily get a couple of Bf-110C's in a mission, in a Spitfire MkI or Hurricane. It is much easier with cannon, though.

[Wrench 9,847]

do NOT mess with mass fraction -- that deals with the aircraft's weight and the energy needed to move it. Put it back where it was, as a good number of the FM parameters are based off that weight.

[+RAVEN 414]

Just thought I'd throw this in. On ALL the aircraft I've made the Min/Max for the Engines, Guns and Fuel tanks is taken from Max output data from meshes I added to the model, then removed before export.. So they are correct for size and volume, too include location in the airframe.

[Stratos 3,191]

Structural factor is the number you are looking for. Jack it up to 2 or 3 and you will have a very tough target, especially for small-calibre bullets like the .303.

I find I can easily get a couple of Bf-110C's in a mission, in a Spitfire MkI or Hurricane. It is much easier with cannon, though.

 

Will that work with modern (cold war) aircrafts against 20 and 30 mm guns?

[Do335 382]

My ingame findings + what I remember TK has said in the TW foras:

 

First you have the size of the hitbox. The larger the hitbox the tougher the airframe is. It's further multiplied by structuralfactor. Since the destruction of one component generally means a disabled/destroyed aircraft, the component with the smallest hitbox becomes the weakpoint, such as a [tail]. Whereas a single [fuselage] without [nose] or [tail] along the entire airframe becomes very hard to destroy since the hitbox is so huge.

 

Secondly you have the damagerating. Some data ins like to set DamageRating=HEAVY instead of DISABLED or DESTROYED, like those usually from A-Team. Add that to a simplied FM you can have some aircraft losing a wing and still flying for an eternity.

 

Thirdly you have armor. What I find is that armor is very effective against kinetic energy, but it does not fend off chemical energy of the cannon shell warheads. For example an aluminum armor of 24 (mm) basically nullifies the 50cal shots (there're still random pens happening, per TK), while even 40mm of the same does little to stop 20mm cannon shells. Steel armor has more than twice the effectiveness of aluminum armor.

 

Fourth there're the (sub) systems, engines, fuel tanks, pilots. With their own hitbox and armor, they generally act like components, but with differences. Engines and fuel tanks catch fire. Pure kinetic bullets like machinegun shots have a much less chance of setting fire compared to HE bullets. These datas are defined in [ObjectFire] section in AIRCRAFTOBJECT.INI. Engines and fuel tanks have a FireSuppression=TRUE setting, which improves chance of putting out the fire over time. Fuel tanks also have a SelfHealing=TRUE setting, which stops fuel leak over time. Pilot kill results in an immediate aircraft kill and triggers canopy eject anim.

 

 

There's another factor which is gun convergence. As said wing mounted guns are very ineffective without setting a convergence. It becomes more complicated when factoring in the AI. While aiming, the AI does not take the position of guns mounted on the airframe into account. It will always assume the guns are at position 0,0,0, only modified by "gunboresightangle" (for example Phantoms with gunpods pointed 1 deg downwards). It doesn't account for guns with different ballistics either, but only uses the ballistics of the first entry in the internal guns section. These make gun convergence settings very tricky for some WW2 planes like say the Bf-109E.

 

 

In execution there's also something weird with the damage engine. Tail aspect shots are generally much less effective compared to flanking shots. Possible explanation being usually a kill is by destroying systems like fuel tanks and engine since those have much smaller hitboxes, and the damage of rear shots are mostly soaked by bigger components like the tail and fuselage. What it ends up encouraging though is energy fighting and deflection shooting, which I think is good.

 

 

So what can be improved? Firstly the hitbox, as many aircraft have them pretty off, or over simplied. Secondly damagerating. Destruction of a component should result in DESTROYED, except left/right Stabs which should be set as DISABLED, this is especially true for 3rd party aircrafts of which might have generic FMs. Thirdly armor settings, see if it can be tuned to more reasonable values. Fourthly gun convergence is a must. Fifth, aircraft machineguns rarely use ball ammo, many have a small warhead containing incendiaries or even explosives. Giving the MG warhead a little weight, with the in-game effect of setting fire easier, can't hurt. And of course while shooting, ensure the target is struck by a steady continuous burst, as machineguns are more like a drill then a hammer. And use deflection shots for even better effects.

 

 

My uhmm.. 20 cents

Edited March 17, 2015 by Do335

[+baffmeister 1,205]

Just thought I'd throw this in. On ALL the aircraft I've made the Min/Max for the Engines, Guns and Fuel tanks is taken from Max output data from meshes I added to the model, then removed before export.. So they are correct for size and volume, too include location in the airframe.

 

If I remember correctly, your Hurricane model had very good damage modeling. I think I experimented with a few things to reduce the flammability of the fuel tanks.

 

Good stuff Do335, thanks.

Edited March 17, 2015 by baffmeister

[ShrikeHawk 384]

Thanks for all the replies everyone.

 

I've been a big fan of gun convergence for a while. It really does make a difference. In the Spit Mk I, the AI were missing everything. Averaging 0.8% hits and no kills. Tweek the guns and now they're actually getting kills and being helpful.

 

Do335 - Thanks for an outstanding and informative post. I really appreciate it. I have much to look over.

 

Baff - I will definitely look into Mues' Lod viewer. Could be really handy. Thanks for that.

 

Wrench - I'll put the settings back. Changes didn't help what I wanted anyway. It's good know about the balancing.

 

Gatling20 - Thanks for the confirmation. Much appreciated.

 

Alrighty, I'm off to have a look at the hitboxes

 

Cheers!

[ShrikeHawk 384]

LOD viewer works great, but hang on. Do need to be able to edit the LOD to change the hitboxes? Could I just change the collision points or the min/max extents?

[Wrench 9,847]

min/max extents are set only in max (but are possibly 'adjustable' in the data ini). More ot less, if I under stand them correctly, they describe the physical space the object takes up.

 

I do recall GregoryP making adjustments to them on some of the AvHistory FMs.

 

this is from TKs Mirage3C, from the fuselage section:

 

 

MinExtentPosition=-0.89,-6.57,-0.70
MaxExtentPosition= 0.89, 3.15, 0.70
CollisionPoint[001]=-1.40, 5.66,-0.91
CollisionPoint[002]= 1.40, 5.66,-0.91
CollisionPoint[003]= 1.23,-3.74,-1.17
CollisionPoint[004]=-1.23,-3.74,-1.17
CollisionPoint[005]= 0.00,-7.54, 0.50
CollisionPoint[006]= 1.21, 5.66, 0.53
CollisionPoint[007]=-1.21, 5.66, 0.53

 

you can see they don't exactly match each other, which is what one would assume (oh! that word!!) if they describe the exact "space" taken up the 'world'.

 

As I under stand collision points -- and I'm probably quite wrong -- they are the spots that the model "touches" other things, like mid-air collisions, missile and gun hits, the ground and so forth.

 

In truth, I think a 3d guy might have to answer that one, cause I might be waaaaaaaaaaaaay off the beam!

[Do335 382]

ShrikeHawk sorry for the text wall eheh. Just happened to spend a lotta time on this stuff..

[FastCargo 412]

Min and MaxExtentPosition represent  the 'corners' of a box that encompass the part of the aircraft you are defining.  It primarily serves as a 'hitbox' with a secondary function of a radar size definition...the bigger the box, the bigger the radar signature of that part.

 

CollisionPoints on the other hand definite a line or 'plane' of a part that is used to determine collisions with the ground or objects.  So vertical stab may only need two points to make a 'line', where as a wing might require several points to make a 'plane'.

 

Neither one really have anything to do with the actual LOD shape, but there is a MAX addon that can make a list of Min/MaxExtents.  In addition, LODviewer now provides that same functionality.

 

FC 

[ShrikeHawk 384]

ShrikeHawk sorry for the text wall eheh. Just happened to spend a lotta time on this stuff..

 

Don't be! That was great information and I thought every bit was useful. Thanks very much!

 

Thanks Kevin and FastCargo. I think I've got what I need now. Much appreciated!

[+Geezer 3,569]

 

Fourth there're the (sub) systems, engines, fuel tanks, pilots. With their own hitbox and armor, they generally act like components, but with differences. Engines and fuel tanks catch fire. Pure kinetic bullets like machinegun shots have a much less chance of setting fire compared to HE bullets. These datas are defined in [ObjectFire] section in AIRCRAFTOBJECT.INI. Engines and fuel tanks have a FireSuppression=TRUE setting, which improves chance of putting out the fire over time. Fuel tanks also have a SelfHealing=TRUE setting, which stops fuel leak over time. Pilot kill results in an immediate aircraft kill and triggers canopy eject anim.

 

 

 

This is a very interesting thread.  Does the software also recognize subsystems such as oil coolers or radiators?

[Wrench 9,847]

radiators, yes. oil coolers, don' t know, but as it's a radiator??

[+RAVEN 414]

The aircraft, cockpit or any object in game is just eye candy. Everything else is defined by a data file, be it a FM or just a simple .ini. With the right _Data.ini you can make a brick model fly like a F-35 or a Camo-net launch like a SAM. With that said, I'd like to say Thank you to the people that spend long hours working on the FM's.

 

Raven

[Do335 382]

This is a very interesting thread.  Does the software also recognize subsystems such as oil coolers or radiators?

Geezer I've never seen a radiator systemtype. But one can set it up as a component and set Damagerating=DISABLED to simulate a crippled engine. Apparently TK never went to such trouble for the SF stock planes, it'd be interesting if he did something extra for FE tho.

Edited March 19, 2015 by Do335

[+Geezer 3,569]

Geezer I've never seen a radiator systemtype. But one can set it up as a component and set Damagerating=DISABLED to simulate a crippled engine. Apparently TK never went to such trouble for the SF stock planes, it'd be interesting if he did something extra for FE tho.

 

Thanks for the useful information.

[+Geezer 3,569]

Shot below illustrates why I am curious about oil cooler and radiator damage.

 

[+logan4 847]

The game system in theory differentiates the following type of sub systems:

Pneumatic_system

Hydraulic_system

Electrical_system

Fuel_system

Cooling_system

Oil_system

 

So my guess (oh that word) if you set the oil radiator in the _data.ini similarly like any of the fuel tank entries (node name, min/max extents) only with the SystemType=Oil_system (or your pick) entry. You could be able to simulate damages done to that item which might result in later an engine overheat/failure.

[Stratos 3,191]

Ok in case I will like to make a plane more resistant to gun shells and missiles what I need to do?

[+logan4 847]

You can add armor materials if none present or change the material type and thickness.

 

Materials:

WOOD

FIBERGLASS

GLASS

TITANIUM

STEEL

ALLUMINIUM

 

Application on each major part or direction you wish to strengthen.

 

HasArmor=TRUE

ArmorMaterial=ALUMINUM

Armor[FRONT].Thickness=4

Armor

.Thickness=4

Armor

.Thickness=4

Armor[REAR].Thickness=4

Armor[TOP].Thickness=4

Armor[bOTTOM].Thickness=4

 

Edit: also you can decrease the hitbox size, so harder to hit it.

Edited April 12, 2015 by logan4

[Fubar512 1,350]

Ok in case I will like to make a plane more resistant to gun shells and missiles what I need to do?

What do you need to do?  Stop presenting yourself as a target, maybe? 

[Stratos 3,191]

What do you need to do?  Stop presenting yourself as a target, maybe? 

 

Enhance the toughness of some aircrafts a bit.