Missile Explosions and Hull Damage Detection

Collision groups are the reason that the problem is arising for me. I am creating a massive FX pack that is based on damage-per-section and it all works out great except if their is a problem with the missile/torpedo splash damage carrying over to mutiple collision groups and giving bonus damage. (up to 8 times as much in some places)

This is indeed a very annoying problem that we’ve been struggling with in Flak for quite some time. So far, I’ve simply tried to find a balance in a sufficiently high explosion radius that does not sacrifice fighter balance in the process.

One thing that may be worth looking into, however, is moving the hull_damage and shield_damage entries on your missiles/torpedoes from [Explosion] to [Munition], without changing any other properties of the missile. I haven’t had time to extensively test this, but it seems to allow guided munitions to damage any part of any craft only once - however, it also sacrifices any splash damage, which can be a large balancing part of most ordinance (twin-torpedo Stealth Bombers would be crazy overpowered in Flak if they were able to bomb at close ranges without killing themselves). I’m not sure if it still takes detonation_dist into account (so if the missile is set to detonate16m from the target, I don’t know if it will still damage the target from that range or if it must physically hit the target), and of course at the end of the day it’s still a sloppy workaround.

I think M0tah was originally intending to look at a Hook-side solution for this, but I’m not sure what his progress was - he’s been busy as of late and hasn’t had time for FLHook work. Adoxa, you said ordinance still returned a specific damage type (16) even though it didn’t always damage the craft?

Maybe instead of moving both shield and hull damage just move the hull damage to the [Munition] entries (Since Shield damage still works). Or leave the [damage] entry and balance the damage out between the munition and damage (So you have the splash damage and not an overly damaging weapon).

Decided to investigate the issue; here’s what I found.

0x0C->0x00 in server.dll, 0x960C = fixes explosion damage at full strength
```This should fix the issue (it has in my testing so far).

Explanation
FL hardcodes three different multipliers of damage for explosions - 1, 2/3, 1/3, and 0, depending on how far away from the center of the object the explosion is. As far as I can tell, this is computed using the following mapping:
Distance^2 -> Strength
<= (Explosion radius)^2 * 0.1111… -> 1
<= (Explosion radius)^2 * 0.4444... -> 2/3
<= (Explosion radius)^2 -> 1/3
> (Explosion radius)^2 -> 0
So when the hit is farther than the explosion's radius away from the root of the ship, no damage is dealt. The above hack fixes the multiplier at 1 regardless of the distance.

Absolutely amazing M0tah

Thanks

now i can continue my work in peace.

(and motah, is their a way i can download 88flak’s server.dll with the hack?)

In single player, this hack will generate additional damage. For example, I changed the Javelin to do 10 damage and Flint to a Rheinland battleship (rm_r_battleship). Firing a missile into the center hits two groups (Rh_main_lod1/DpMain & Rh_midfrnt_lod1/DpMidFrnt) for 20 damage. Applying the patch then does 30 damage - the two groups plus presumably the ship as a whole.

The damage is actually found a little further down, in the function at 0x(6ce)9690. In SP, GetRadius returns a valid value, but in MP it is returning 0. I think the real problem is with something used by GetBoundingSphere. That’s as far as I went, back to you, M0tah…

It won’t be a problem for any model without subcomponents.

Nice work M0tah!

adoxa wrote:
In single player, this hack will generate additional damage. For example, I changed the Javelin to do 10 damage and Flint to a Rheinland battleship (rm_r_battleship). Firing a missile into the center hits two groups (Rh_main_lod1/DpMain & Rh_midfrnt_lod1/DpMidFrnt) for 20 damage. Applying the patch then does 30 damage - the two groups plus presumably the ship as a whole.

The damage is actually found a little further down, in the function at 0x(6ce)9690. In SP, GetRadius returns a valid value, but in MP it is returning 0. I think the real problem is with something used by GetBoundingSphere. That’s as far as I went, back to you, M0tah…

Did some more testing, and I couldn’t get CArchGroup::GetRadius to be called at all, in either MP or SP (though 0x9690 is). You are referring to that call in 0x9690, correct?

in a quick test i just did i also couldnt break on getradius within the mentioned function

It seems that part of the function is only called if the object has collision groups (restoring the original Flint still broke; commenting the [CollisionGroup] entries failed to break). Even so, these particular collision groups are different to the battleship ones, generating a radius of 0 (it skips the bounding sphere altogether).