LuaBehaviour

Inherits from: Behaviour

The gameObject property allows you to interact with the GameObject that this LuaBehaviour instance (remember, accessed by self in Lua scripts) is attached to. This equips your Lua script with the ability to manipulate the GameObject in complex ways.

local go = self.gameObject
print("Hi! My name is " .. go.name)

The transform property provides you access to the Transform component of the GameObject attached to this LuaBehaviour instance. With this, the Lua script can modify the GameObject's 3D position, rotation, and scale in the game world.

local t = self.transform
print("Hi! I'm located at " .. tostring(t.position))

This event is triggered when a GameObject, equipped with a Collider (and one of them must have a Class.RigidBody), stops colliding with another GameObject. This could be useful for game logic where an action occurs as soon as a collision ends, like playing a sound effect when a ball leaves a wall. Note that both GameObjects need a collider and the IsTrigger property on both colliders must be set to false. Unity's Documentation here

function self:OnCollisionExit(collision : Collision)
    print("I stopped colliding with and touching a collider named " .. collision.gameObject.name)
end

The OnCollisionStay event triggers when a GameObject continues to collide with another GameObject. This can be handy for scenarios where an action must be continuously performed while collision is ongoing - maybe your character loses health as long as it keeps touching a spiky wall. Similar to OnCollisionExit, both GameObjects require a Class.Collider and one needs a Class.RigidBody attached. Unity's Documentation here

function self:OnCollisionStay(collision : Collision)
    print("I am still colliding with and touching a collider named " .. collision.gameObject.name)
end

The OnCollisionEnter event is triggered when a GameObject, equipped with a Class.Collider, collides with another GameObject. Handy for scenarios when an action should occur as soon as a collision begins - for example, when your character touches a coin, the coin disappears and the score increases. Like the other collision events, both GameObjects need a collider and the IsTrigger property on both colliders must be set to false. Unity's Documentation here

function self:OnCollisionEnter(collision : Collision)
    print("I collided with a collider named " .. collision.gameObject.name)
end

The OnTriggerExit event signals when a GameObject exits a trigger Collider. This implies a GameObject ceases to intersect with the collider's trigger space. Examples of its usage include teleporting a character when it steps out of a magical portal. Note that both GameObjects require a Class.Collider, while at least one GameObject must have a set IsTrigger to true. Unity's Documentation here

function self:OnTriggerEnter(other : Collider)
  print("This triggering collider left: " .. other.gameObject.name)
end

The OnTriggerStay event is invoked continuously for every physics update where a GameObject intersects a trigger collider. It is useful for scenarios where an action must continue while a GameObject is within a certain area, like a player receiving healing effects while inside a healing zone. This event requires both GameObjects to have a Class.Collider with at least one GameObject having its IsTrigger set to true. Unity's Documentation here

function self:OnTriggerStay(other : Collider)
  print("The triggering collider that has not left is named " .. other.gameObject.name)
end

The OnTriggerEnter event is triggered when a GameObject intersects a trigger collider. This can be useful for a variety of scenarios, like a player stepping on a tripwire that witnesses a trap. Again, both GameObjects require a Class.Collider component with at least one GameObject having its IsTrigger property set to true. Unity's Documentation here

function self:OnTriggerEnter(other : Collider)
  print("I was triggered by a collider named " .. other.gameObject.name)
end

The Update event is fired every frame to update non-physics related changes or input. It's commonly used for updating animations, game logic, collecting input, or debugging. Note that the frequency of the Update call might not be consistent as it depends on the frame rate. Unity's Documentation here

function self:Update()
  print("This frame took " .. Time.deltaTime .. "seconds")
end

LateUpdate is called every frame, just like Update but it is always called after all Update functions are called. This is especially useful if you need to order actions to happen in a sequence. For instance, you would want to move your character in the Update function, then adjust the camera position in the LateUpdate to correspond to the character's new position. Unity's Documentation here

Initialize With EventConnection

function self:LateUpdate()
  print("This frame took " .. Time.deltaTime .. "seconds, but I'm happening after all the other normal Updates occured")
end

FixedUpdate is called every fixed frame-rate frame to perform physics-related changes. Use this for applying forces, gravity or tweaking physics-related game settings. Unlike Update, FixedUpdate is consistent, ensuring that physics plays out the same way regardless of the frame rate of the game. Unity's Documentation here

function self:FixedUpdate()
  print("This physics step took " .. Time.fixedDeltaTime .. " seconds and will always take that long, unless manually changed")
end

The Start event is triggered when a LuaBehaviour is enabled just before any Update methods are called for the first time. This can be useful for initializing variables or performing setup operations. Note that unlike Unity, Highrise does not have an Awake function. Code that you would typically place in the Awake function is placed within the Lua script outside of any function, which Highrise will execute immediately when the script loads. Unity's Documentation here

function self:Start()
  print("I started. This is still the first frame I am alive!")
end

print("I executed immediately! Not being in a function is kind of like Awake()")