Zones

A zone is a charged area that grows around the user, holds for a while, and applies its effects to what is inside. Two classes share one parent:

Class	For
ZoneAbility	a sphere that applies effects to entities inside it
SpreadingBlockAbility	a zone that also converts the ground, and restores it at the end
DomainAbility	their shared parent: the zone sounds and the "entity left the zone" tracking

ZoneAbility

Lifecycle

1. First press: the user must be on the ground (unless onGroundOnly is false). A sphere is created, the charge starts, and the user is rooted for chargeTime ticks.
2. During the charge: the sphere grows. Pressing again releases the zone early, at the size it has reached, but only once minChargeTime ticks have passed.
3. Charge end: the zone holds for zoneTime ticks, applying its effects every effect interval.
4. Pressing during the zone closes it.
5. Close: effects listed for clearing are removed, the closing sound plays, and the cooldown starts in proportion to the size reached: maxCooldown x (size / maxZoneSize), clamped between minCooldown and maxCooldown.

A minimal zone

public class MyZoneAbility extends ZoneAbility {

    public MyZoneAbility(AbilityCore<MyZoneAbility> core) {
        super(core);
        this.maxZoneSize = 20;
        this.chargeTime = 100;
        this.zoneTime = 400.0F;
        this.zoneColor = new Color(80, 160, 255, 75);
        this.setEffectsTickInterval(20);
    }

    @Override
    protected void applyEffectToLivingEntityInZone(LivingEntity owner, LivingEntity target) {
        this.applyOrRefresh(target, MobEffects.MOVEMENT_SLOWDOWN, 40, 1, false, true);
    }

    @Override
    protected List<MobEffect> getZoneEffectsToClearOnEnd() {
        return List.of(MobEffects.MOVEMENT_SLOWDOWN);
    }
}

Settings

Set these from your constructor.

Field	Default	Meaning
maxZoneSize	128	radius at a full charge
minZoneSize	0	smallest radius
chargeTime	240	ticks to reach maxZoneSize
minChargeTime	60	ticks before an early release is accepted
zoneTime	1200	ticks the zone holds after the charge
minCooldown, maxCooldown	2400	bounds of the proportional cooldown
cancelCooldown	10	length of the closing animation when the user closes the zone
zoneColor	white, alpha 50	the sphere's colour
onGroundOnly	true	refuse the first press in mid-air
applyEffectOnUser	false	include the user in the zone's targets
allowAnimation	true	play the charging pose
enableBlockOverlay	false	highlight the blocks inside the zone on clients
overlayArgb	0x50FFFFFF	the overlay colour
targetsCheck	enemies	which living entities are affected

Change the effect rate with setEffectsTickInterval(ticks): it is safe to call from the constructor.

Always give zoneColor an alpha

The colour goes to the sphere as is. new Color(r, g, b) has an alpha of 255, which paints an opaque dome nobody can see out of. Use the four-argument constructor: around 50 for a saturated colour, 75 for a mid tone, 110 to 120 for a dark one.

Hooks

Override	Called
applyEffectToLivingEntityInZone(owner, target)	for each targeted living entity inside, every effect interval
onEntityLeavesZone(owner, target)	once, when an entity that was affected is no longer inside
getZoneEffectsToClearOnEnd()	at close, the effects to strip from everything that was affected
endChargeBlocks, continuityTickBlocks, continuityEndBlocks	block work at charge end, per tick, and at close
applyEffectToNonLivingEntityInZone(owner, target)	for items, arrows, orbs... only if affectsNonLivingEntities() returns true

The non-living hook needs its switch: overriding applyEffectToNonLivingEntityInZone alone does nothing, because the scan never hands it a target. Override affectsNonLivingEntities() to return true as well. It widens every scan to every entity in the zone's box, so only do it when the zone really acts on them.

Useful helpers: applyOrRefresh(target, effect, duration, amplifier, ambient, particles), isEntityInZone(entity), isPositionInZone(pos), getZoneSize(), getCenterBlock().

Zone damage is an unguarded pulse

applyEffectToLivingEntityInZone runs on every effect interval, for every target. Deal damage there with hurtTarget, not hurtBurst, unless the interval is longer than 10 ticks. See Damage.

Interrupting a charge from outside

DomainAbility.interruptCharge(entity) cancels a zone's charge as if it had never started, for an ability that breaks the caster's concentration. It returns whether a charge was running; nothing is put on cooldown.

AkumaLib calls it itself for every AbilityHelper.emergencyStopAbility - kairoseki, water, handcuffs, any disableAbilities caller - through AkumaCharges.interrupt, which is also the call to make for an interruption of your own when the ability may not be a domain. See Charges.

Class	What it takes back
ZoneAbility	the sphere spawned at charge start, the charge's MOVEMENT_BLOCKED and pose. A closing zone (the owner shutting it) is left alone
SpreadingBlockAbility	every block the charge had already spread, through the same restore queue as a normal close (over restoreTicks), the lock and the pose
any other DomainAbility	nothing: the default returns false

Neither charge-component call is safe on a domain

ChargeComponent.stopCharging runs the charge-end event, and a domain opens its zone there, at the size reached. forceStopCharging skips the event but leaves what the charge put in the world: a sphere that is never discarded, or blocks with no continuity left to restore them. Call AkumaCharges.interrupt, which picks interruptCharge for a domain.

Why the spreading restore is queued

It used to be restoreImmediately, which at a large radius is tens of thousands of setBlock calls in one tick. The zone stays in ACTIVE_ZONES until the queue is drained, so a disconnect in between still restores everything, and a recast flushes whatever is left first.

Zone sounds: ZoneSoundSet

DomainAbility plays four sounds over a zone's life. Declare them as data from your constructor. Leaving setZoneSounds unset plays the Ope Ope no Mi's Room sounds: a deliberate fallback, not a default to ship with.

this.setZoneSounds(ZoneSoundSet.of(MySounds.ZONE_CREATE, MySounds.ZONE_CHARGE,
                MySounds.ZONE_EXPAND, MySounds.ZONE_END)
        .pitches(0.9F, 0.85F, 1.0F, 0.9F)
        .jitters(0.0F, 0.2F, 0.0F, 0.0F));

Slot	When	Default volume
create	the charge starts	3.0
interval	repeatedly while the zone charges	1.5
charge end	the zone reaches full size	3.0
end	the zone closes	2.0

Pass the RegistryObjects directly, without .get(). .volumes(...), .pitches(...) and .jitters(...) take one value per slot, in that order. Give the interval slot a pitch jitter of about 0.2: a charge sound repeated for hundreds of ticks turns robotic, and the jitter keeps it natural.

Declare the interval clip's length

The interval slot is replayed every 18 ticks by default - the pace of the base mod's short Room sound. A longer clip restarted that often plays two or three copies of itself over each other for the whole charge. Give the set the clip's length and it replays it only once a play has finished:

this.setZoneSounds(ZoneSoundSet.of(MySounds.ZONE_CREATE, MySounds.ZONE_CHARGE,
                MySounds.ZONE_EXPAND, MySounds.ZONE_END)
        .pitches(1.0F, 0.8F, 1.0F, 1.0F)
        .intervalClip(3.0F));   // seconds, at pitch 1

The cadence is worked out at the slot's base pitch, its slowest, since jitter only raises the pitch and a lower pitch plays a clip for longer: a 3 s clip at pitch 0.8 lasts 3.75 s, so it is replayed every 75 ticks. setZoneSounds sets playSoundInterval from it; assign that field yourself only before the call, or not at all.

A clip replayed back to back also wants a short fade at both ends, or each restart clicks.

The zone that also converts the ground has its own page: Spreading blocks.