April
28
2015

Learn more about trigger machines and what you can use them for.

Trigger machines are Unity components that are added to game objects. They’re mostly used for

A trigger machine component can be added through the components menu (Makinom > Machines > Trigger Machine) or the scene wizard (Add Machine > Trigger Machine). A game object with a trigger machine is represented in the Unity scene view by this gizmo icon:

TriggerMachineComponent Icon

You can learn more about machine components in general and their basic settings in this how-to.

Start Types

A trigger machine is started by trigger callback functions. This requires collider and rigidbody components on the game objects and the machine’s collider to have Is Trigger enabled.

By default, trigger machines can only be started when the player’s game object enters the trigger. Optionally, they can also be started by other game objects – this can further limited to game objects with a defined name, tag or component attached.

Trigger Enter

Started when a game object enters the machine’s trigger. It’s implemented in the component’s OnTriggerEnter and OnTriggerEnter2D functions.

Additional Start Conditions

The Trigger Enter start type can optionally be limited by a layer mask. This can be used to only start the machine when game objects of a defined layer enter the trigger.

Example

This start type can be used to display a notification when the player enters an area of the scene. Use a Show Dialogue node using the Auto Close dialogue type to show a notification for a short time.

Trigger Stay

Started while a game object stays in the machine’s trigger. It’s implemented in the component’s OnTriggerStay and OnTriggerStay2D functions.

Additional Start Conditions

The Trigger Stay start type can optionally be limited by a layer mask. This can be used to only start the machine when game objects of a defined layer stays in the trigger.

Example

This start type can be used to reduce the health of the player while he stays within a dangerous area. Use a Change Variables node to change variables (e.g. int variable health).

Trigger Exit

Started when a game object leaves the machine’s trigger. It’s implemented in the component’s OnTriggerExit and OnTriggerExit2D functions.

Additional Start Conditions

The Trigger Exit start type can optionally be limited by a layer mask. This can be used to only start the machine when game objects of a defined layer leaves the trigger.

Example

This start type can be used to disable game objects when the player leaves the area. Use a Activate Object node to enable/disable game objects.