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Damage model

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1 Damage model on Fri Mar 12, 2010 9:11 am


While I've been doing new air-air FX for the Open Falcon, I watched a lot of vids showing missile hits and all stuff like that.
I've thought about a new damage system that time (too bad I didn't wrote it down somewhere), but eventually forgot the whole idea due to other things. Now, after watching your latest vids I've recalled it and perhaps (if it's possible and you don't have currently a better one) you can use the idea.

I'll try to explain it in four examples of an F-18 hit by sidewinder, amraam, gun and a collision.
First let's splitt the Hornet into a few pieces, each being a separate model or element (prefered the first one). I case of F-18 there would be parts: nose, front fuselage, center fuselage, rear fuselage, each for one wing and each for one tail's element plus a few special ones: cockpit, radar, each one for gears and each one for engines.
Here's its dependence chart:

Destroying or damaging those parts will affect the aircraft behaviour:
Part NameDamageDestroyed
Nosedecrease maximum speed and decrease stabilityas before with stronger affect
Front fuselagedisable some avionicsdestroy AC
Left/right wingsdecrease stability, other dmg based on dmg typdestabilize AC (similar to the current 7G hit effect)
Center Fuselagebased on dmg typedestroy AC
Rear fuselagedamage enginesexplosion blast
L/R Stabilizerdecrease stabilityas before with stronger effect (destabilize if both are destroyed)
L/R Elevatordecrease manoeuvrabilitylost control
It will also damage or disable all objects in those parts.
Each part will have a maximum dmg point value (it's a variable important that counts for fire, bullet and collision). If that limit is exceeded the part will destroy/detach. A fire deals constant damage at a certain rate (based on its strength).

Now, let's first talk about a sidewinder case.
In most (if not all) vids I've seen sidewinders didn't explode near the aircraft, but hit them directly. It sometimes went very closely to a target but missed it and didn't explode. So, only direct hit counts. The other thing was that there was no "blast" effect, but that's only a graphical thing.
Now, when our AC is hit, the first thing, that the game checks, is, where it was hit and then completely wipe out that part destroy all its "children", and separate all dependant parts. Also, it will check if that part has fuel. If it has that it will also create fire, dependent on amount of fuel in that part. A large amount of fuel will create an explosion blast (the same thing which will create an Amraam hit; I'll explain that later). The lower amount of fuel will create a fire, which will spread across other parts (speed depending on its strenght), damaging them (again, a large fuel storage encounter will create an explosion) until fire is extinguished, or the part is destroyed.
That means, when the AC is hit for ex. in left wing, which had medium amount of fuel, this wing will be destroyed and fire will be created on central fuselage (which has, for ex, also a medium amount of fuel). After a few seconds the fuel stored in that part will ignite, spreading the fire to front and rear fuselage, and after a few other seconds destroy the central fuselage tearing whole AC apart. That's exactly how it looked on most vids I've seen.
If there's no fuel, then the impact, just as strong mid-air collision, will just destroy that part and detach all dependant to it. It can also damage adjective parts at random value, like for ex. a hit in left elevator will destroy it and damage left engine a bit. All hits can also damage other, non adjective parts at random value (less likely than adjective ones) to simulate splinter hits (damaging by the same way as the bullet, which will also be explained later).

Ok, now for Amraam hit.
The Amraam can explode in close range to its target. And it carries more payload than AIM9.
So, when Amraam explodes it creates an explosion blast, which is (ignoring visual effect) nothing more than an invisible sphere. Now, the game engine checks what parts are within that sphere, and how close to its center. The parts that are close to it will be destroyed, and if they're storing fuel, it will automatically ignite (or explode creating another explosion blast). The further parts, but still within the radius, will be only damaged to simulate splinters hits. The rest will work just like before.

The bullet hits.
If a part is hit by a bullet it's simply damaged, based on bullet damage value. Also, the bullets can't completely destroy parts, but if they deliver enough damage they can detach it from the A, which results in the same effect as destroyed, but the part visually doesn't disappear, but brakes away from aircraft. Also, this alone don't create fire or explosion. But, if a bullet hits part with fuel there's a chance that it will create spark that will ignite the fire (another random value). If it will, fire will be created on that part. If it won't it will only create a hole, and the AC will start to loose fuel.

Collision works similar to the bullet hit but instead of a fixed damage value of a bullet it will also calculate how much damage the collision will inflict. This can be calculated from targets weights and speeds. I just don't know what formula it should use, but I know, that the speed will control the overall damage value created by the collision, while the weight will control how many of that damage will be dealt to colliding objects. In ex. first AC weights 40lbs, and second 20lbs. Based on their speed the collision will create for ex. 10 dmg points. Weights ratio is 2:1, which means the first one will receive about 4 dmg points to the parts that collided and the second will recieve about 6 dmg points.

Hope this helps at least a bit.
Not to mention it would be great, if a system like that will be implemented. Very Happy
Anyway, tell me what you think about it.

2 Re: Damage model on Fri Mar 12, 2010 11:18 am


Thanks, will implement it somehow

3 Re: Damage model on Sun Mar 14, 2010 9:18 am


Nice note there Harpoon. How about extending the same to avionics wiring Cool

4 Re: Damage model on Mon Mar 15, 2010 3:16 pm


It seems like most of the damage to individual subsystems is unpredictable, but you could also consider damage to the ECS system which could result in, for example:
- Loss of cabin pressurization, effectively limiting the aircraft ceiling, possible loss of oxygen to the aircrew
- Inadequate cooling, require certain avionics to be shut off, may need to resort to emergency cooling, limit use of the radar

Here's an Approach (Lessons Learned type) article detailing such an instance of loss of cooling air and associated AV AIR HOT and OBOGS DEGD

It would be nice to implement as many emergency conditions as feasible so that knowing the emergency procedures will pay off. The only major problem is that their occurrence would be completely random because it would probably be too much work to even do a simple simulation for every subsystem. When flying as normal, the pilot is normally given the benefit of the doubt that nothing is going to go wrong. When the pilot overtaxes the aircraft or his aircraft receives battle damage, most of the time it will be a catastrophic failure. However, there is a lot of middle ground. You could go beyond just impairing the flight capabilities of the aircraft and requiring no more than a few simple precautions of the pilot knowing his aircraft is damaged. If the pilot acts quickly enough, a series of potentially catastrophic, but recoverable emergencies should give him the chance to get back in the fight or at least make it back to base in one piece.

5 Emergencies on Mon Mar 15, 2010 4:53 pm


I recommend the following emergencies: Engine fire in flight/on ground, APU fire, Double generator failure, Single Generator Fail, Dual Bleed Air Caution, Directional Control on takeoff or landing, and out of control. These are the fairly time critical emergencies. There are simple pilot actions that should remedy the biggest danger and allow the pilot to get home.

6 Re: Damage model on Mon Mar 15, 2010 7:14 pm


Just out of curiosity, do they happen often "on duty"?

7 Emergencies on Mon Mar 15, 2010 8:15 pm


Not often, the guys take pretty good care of the aircraft. Fires are few and far between (maybe 1 every 2 years or so), engine failures aren't that uncommon. Normally something happens (oil pressure) that will make you want to secure the engine, and come back single engine. You tend to get some of transitory flight control cautions (FCS), but a reset usually clears it. Likely due to some controls not scheduling fast enough during maneuvers. The jet is fairly easy to maintain.

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