Reverse engineering the mechanism to create an explosive weapon can be difficult, especially since many of the EditorIDs simply do not show up in text search.
To add an explosion to a weapon, you need to create at least four types of base object: the Weapon itself, and one or more Ammo, Projectile, and Explosion types. If there are multiple types of ammo, you will also need a FormList.
As an example, here is a slight simplification of the Missile Launcher, as seen in Fallout: New Vegas, demonstrating the two ways to specify the Projectile.
- WeapMissileLauncher - the Weapon item itself, specifying the valid Ammo (or FormList of Ammos), and the default Projectile. In Fallout3, the default is the only Projectile the weapon can have.
- The "Ammunition" is set to AmmoListMissile.
- Under the "Art and Sound" tab, "Projectile" is set to MissileProjectile.
- AmmoListMissile - an optional FormList of valid ammo types for this weapon, needed in this case since there are multiple types of Missile ammo. If there were only one, the Weapon could have pointed directly to that instead of to the list.
- This FormList contains a reference to AmmoMissile.
- This FormList also contains a reference to AmmoMissileHE.
- AmmoMissile - an Ammo type for this weapon (though there are others). Use this for Object Effects that affect the target.
- "Projectile" is set to NONE on this ammo, so it defaults to the weapon's Projectile.
- AmmoMissileHE - In Fallout: New Vegas, Ammo has been significantly empowered, so that it can specify Object Effects to run on the target Actor, and also specify a different Projectile to the weapon's default - which this does.
- This Ammo contains a reference to MissileProjectileHE
- MissileProjectile - Although the ammo has various effects that can trigger when it hits, it's this Projectile that handles the explosion. This also permits Object Effects that run on the explosion, rather than the target, so you can have effects that trigger where the object impacts even if it doesn't hit an Actor.
- MissileProjectileHE - Just like the above, but links to a larger explosion.
- MissileExplosion - the Explosion type.
- MissileExplosionHE - the Explosion type for the HE form of the ammo.
So the Weapon specifies the FormList which specifies the Ammo; and also specifies the Projectile which specifies the Explosion.
In F:NV, alternatively, the Weapon can specify the FormList which specifies the Ammo which specifies the Projectile which specifies the Explosion.
These two methods can be mix-and-matched, as above, where one type of ammo specified a Projectile, while the other went with the Weapon's default Projectile.
- ID: Unique identifier for this form.
- Name: Display name.
- Force: The push of the blast.
- Damage: The amount of damage that can be received if standing within the blast radius.
- Radius: This is the radius of the area of influence of the explosion; any rigid body within this radius is pushed, and any reference within it may be damaged.
- IS Radius: Radius of the area that will see the ImageSpace effect.
- Always Uses World Orientation: Whether the blast will be aligned with the ground.
- Ignore LOS Check: Sets the explosion to ignore a line-of-site check to the target.
- Push Explosion Source Ref Only: Select this to have the explosion's force only affect the object itself. Used in destruction data.
- Ignore Imagespace Swap: Overrides close proximity explosion optimization (which removes the blinding flash from explosions).
- RAD Level: Amount of RADs per second.
- Radius: Size of radiation effect.
- Dissipation Time: Duration of radiation effect.
- Art File: Name of the file that contains the special effect graphic.
- Light: Editor ID of the light used by explosion. Currently unsupported.
- Enchantment: Object Effect that gets applied to explosion.
- Sound 1: Sound effect played during explosion.
- Sound 2: Second sound effect played during explosion.
- IS Mod: The ImageSpace Modifier that plays when explosion occurs.
- Impact Data Set: Sets up the effect the explosion has on its impact with different materials as the blast radiates outward.
- Sound Level: Sets the volume of the explosion for detection purposes.
- Knock Down Living Actors: Three radio button options. "Always" will always knock down living actors. "By Formula" will determine knockdown according to a formula. "Never" will never knock down living actors.
New in 1.5:
- Placed Impact Object: Object placed at the point of the explosion. Example of use seen in Broken Steel DLC for placing the Tesla chain step objects which shoot targets surrounding the point of impact, and also blow up Vertibirds in one shot.
- An explosion's orientation if "Always uses world orientation" is not checked depends on the type of projectile that created it. A beam will create an explosion normal to the surface it hits, a missile will create an explosion at right angles to its angle of incidence.
- RefIDs assigned to explosions will be marked for deletion once the explosion has run its course.
- Explosions with a radius of 0 will cause a CTD if they occur underwater.
- Placed Impact Objects with scripts behave oddly. Their scripts will run but they will not return values for GetSelf.
- Placed Impact Objects will spawn 2 of the selected item if the explosion does not have a mesh. If you want an explosion with no visuals, use meshes\effects\fxnullexplosionart.nif to avoid this issue.