The fragmentation system in ACE3 is a significant improvement over the fragmentation system in ACE2. Previously the system relied on fuzzy math from the values of `indirectHit` and `indirectHitRange` in `CfgAmmo` to calculate roughly the velocity and range of fragmentation. This had some serious drawbacks, especially in the case of smaller explosives such as hand grenades and 40mm grenades where lethality was lower than desired.
In ACE3 the system has moved away from what "feels" right to actual explosive engineering equations, primarily the [Gurney equations](http://en.wikipedia.org/wiki/Gurney_equations). This allows us to get close to the actual fragmentation velocities that would be produced by an explosive configuration similar to type of ammo we are simulating.
The system for the end-developer is easy to use, and only requires minimal research into the type of ammo being represented.
The maximum number of fragments that the real munition would create. Frag count affects the chance of being hit by a fragment and the maximum range in which a fragment may hit a unit. Frag count may be found online, inferred from similar munitions, or derived based on desired hit distance. For a desired distance, the frag count ($$N_{frag}$$) is given by,
where $$P_{hit,min}$$ is 0.5%, the minimum chance to hit that is considered when generating fragments. Therefore, calculating the frag count for a frag grenade with a wounding radius of 15 meters, calculating for a distance of 80 meters may be desired instead.
The amount of metal being fragmented. Generally taken as the entire weight of the warhead, though in some cases you might want to only include the fragmentation jacket or body.
The Gurney constant for explosive force. You can find a list of common explosive types below. If you can not find it here, or want more accurate numbers, just google the type of explosive and Gurney constant and you can find substantial information. This is **not** the detonation velocity of the explosive, do not confuse them†!
The shape factor for the explosive configuration. You should choose it based on the general configuration of explosives/metal in the warhead. Most grenades for example are a sphere. Artillery and aircraft bombs are a cylinder. Mines generally a flat plate. Below is a list of the three common shapes and their factors.
There are other configurations but these are the most common. If you are interested in others check out the wikipedia link given above. Most of these will not correctly function in ACE3 though due to additional variables for the equation.
Tinier fragments do less damage, and generally correlate to lower mass fragments. The `_HD` variants are all higher drag versions. Higher drag version are useful for fragments that are irregular or would not fly very far. Experimentation here is important.
When `1`, the ammunition type will not produce fragments. `ace_frag_skip` does not stop submunitions of the ammo type from producing fragments. `ace_frag_skip` may be helpful for ammunition types that might cause high network load or for explosives that do not produce fragments. Experimentation under network conditions may be required. `ace_frag_skip` takes a higher priority than `ace_frag_force`.
When `1`, the ammunition type will fragment, ignoring internal hit value-based qualifications. `ace_frag_force` takes a lower priority than `ace_frag_skip`.
