UnitClass

A script class that is instanced for every Unit in the game.

A unit represents an AI controlling a Character.

The unit script only runs on the server side.

Can receive events sent with sm.event.sendToUnit.

Fields

Name	Type	Description
`unit`	Unit	The Unit game object belonging to this class instance.
`storage`	Storage	A Storage object that can be used to store data for the next time loading this object after being unloaded.
`data`	any	Data from the "data" json element.
`params`	any	Parameter sent to sm.unit.createUnit.

Constants

Name	Type	Description
`isSaveObject`	boolean	Enables or disables saving of this unit. (Defaults to true)

isSaveObject

Value type: boolean

Enables or disables saving of this unit. (Defaults to true)

If enabled, the Unit will be recreated when loading a game. Otherwise, the Unit is considered a temporary object.

Note: If disabled, self.storage can not be used.

Server + Client

onCreate

UnitClass:server_onCreate(  )
UnitClass:client_onCreate(  )

Called when the scripted object is created. This occurs when a new object is built, spawned, or loaded from the save file.

Parameters:

Name	Type	Description
`self`	table	The class instance.

onDestroy

UnitClass:server_onDestroy(  )
UnitClass:client_onDestroy(  )

Called when the scripted object is destroyed.

Parameters:

Name	Type	Description
`self`	table	The class instance.

onRefresh

UnitClass:server_onRefresh(  )
UnitClass:client_onRefresh(  )

Called if the Lua script attached to the object is modified while the game is running.

Note: This event requires Scrap Mechanic to be running with the '-dev' flag. This will allow scripts to automatically refresh upon changes.

Parameters:

Name	Type	Description
`self`	table	The class instance.

onFixedUpdate

UnitClass:server_onFixedUpdate( timeStep )
UnitClass:client_onFixedUpdate( timeStep )

Called every game tick – 40 ticks a second. If the frame rate is lower than 40 fps, this event may be called twice.

During a fixed update, physics and logic between interactables are updated.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`timeStep`	number	The time period of a tick. (Is always 0.025, a 1/40th of a second.)

Server-only

onReceiveUpdate

UnitClass:server_onReceiveUpdate(  )

Called occasionally to indicate that some time has passed.

For performance reasons; it recommended to use this instead of server_onFixedUpdate for updates that do not need to happen frequently.

Use sm.game.getCurrentTick to calculate the time.

Parameters:

Name	Type	Description
`self`	table	The class instance.

onProjectile

UnitClass:server_onProjectile(
    position,
    airTime,
    velocity,
    projectileName,
    shooter,
    damage,
    customData,
    normal,
    uuid,
    mass
)

Called when the Unit's Character is hit by a projectile.

Note: If the shooter is destroyed before the projectile hits, the shooter value will be nil.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`position`	Vec3	The position in world space where the projectile hit the Unit's Character.
`airTime`	number	The time, in seconds, that the projectile spent flying before the hit.
`velocity`	Vec3	The velocity of the projectile at impact.
`projectileName`	string	The name of the projectile. (Legacy, use uuid instead)
`shooter`	Player/Unit/Shape/Harvestable/nil	The shooter. Can be a Player, Unit, Shape, Harvestable or nil if unknown.
`damage`	integer	The damage value of the projectile.
`customData`	any	A Lua object that can be defined at shoot time using sm.projectile.customProjectileAttack or an other custom version.
`normal`	Vec3	The normal at the point of impact.
`uuid`	Uuid	The uuid of the projectile.
`mass`	number	The mass of the projectile.

onExplosion

UnitClass:server_onExplosion( center, destructionLevel, damage )

Called when the Unit's Character is hit by an explosion.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`center`	Vec3	The center of the explosion.
`destructionLevel`	integer	The level of destruction done by this explosion. Corresponds to the 'durability' rating of a Shape.
`damage`	integer	The damage value of the explosion.

onMelee

UnitClass:server_onMelee( position, attacker, damage, power, direction, normal )

Called when the Unit's Character is hit by a melee hit.

Note: If the attacker is destroyed before the hit lands, the attacker value will be nil.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`position`	Vec3	The position in world space where the Unit's Character was hit.
`attacker`	Player/Unit/nil	The attacker. Can be a Player, Unit or nil if unknown.
`damage`	integer	The damage value of the melee hit.
`power`	number	The physical impact impact of the hit.
`direction`	Vec3	The direction that the melee attack was made.
`normal`	Vec3	The normal at the point of impact.

onCollision

UnitClass:server_onCollision(
    other,
    position,
    selfPointVelocity,
    otherPointVelocity,
    normal
)

Called when the Unit's Character collides with another object.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`other`	Shape/Character/Harvestable/Lift/nil	The other object. Nil if terrain.
`position`	Vec3	The position in world space where the collision occurred.
`selfPointVelocity`	Vec3	The velocity that that the Unit's Character had at the point of collision.
`otherPointVelocity`	Vec3	The velocity that that the other object had at the point of collision.
`normal`	Vec3	The collision normal between the Unit's Character and the other other object.

onCollisionCrush

UnitClass:server_onCollisionCrush(  )

Called when the Unit's Character is crushed.

Parameters:

Name	Type	Description
`self`	table	The class instance.

onUnitUpdate

UnitClass:server_onUnitUpdate( deltaTime )

Called occasionally for units based on how many units are active.

It is recommended to do heavier AI decisions here instead of in server_onFixedUpdate.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`deltaTime`	number	The time, in seconds, since server_onUnitUpdate was last called for this Unit.

onCharacterChangedColor

UnitClass:server_onCharacterChangedColor( color )

Called when the Unit's Character color is set. Either by painting or set using Character.setColor or Character.color.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`color`	Color	The new Color of the Unit's Character.

Client-only

onUpdate

UnitClass:client_onUpdate( deltaTime )

Called every frame.

During a frame update, graphics, animations and effects are updated.

Warning: Because of how frequent this event is called, the game's frame rate is greatly affected by the amount of code executed here. For any non-graphics related code, consider using client_onFixedUpdate instead. If the event is not in use, consider removing it from the script. (Event callbacks that are not implemented will not be called.)

Parameters:

Name	Type	Description
`self`	table	The class instance.
`deltaTime`	number	Delta time since the last frame.

onClientDataUpdate

UnitClass:client_onClientDataUpdate( data, channel )

Called when the client receives new client data updates from the server set with Network.setClientData.

Data set in this way is persistent and the latest data will automatically be sent to new clients.

The data will arrive after client_onCreate during the same tick.

Channel 1 will be received before channel 2 if both are updated.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`data`	any	Any lua object set with Network.setClientData
`channel`	integer	Client data channel, 1 or 2. (default: 1)

onLocalPlayerChangedWorld

UnitClass:client_onLocalPlayerChangedWorld( world )

Called when the client player changes world.

Parameters:

Name	Type	Description
`self`	table	The class instance.
`world`	World	The entered world.