quarta-feira, 30 de abril de 2014

Events Overview in Blueprints

Events are a way of communication between the Unreal Engine and Actors, which are objects that can be added to the level. The scripts that we created in Blueprints are Actions that are executed in response to events that are generated during the game.

To see the events available, right click on the "EventGraph" and expand the "Add Event" category. In this category there are subcategories that group other related events as shown in the image below:

Below is a brief description of the main events:
  • Collision Events: They are triggered when two Actors collide or overlap. 
  • Damage Events: They inform Damage suffered by the Actor.
  • Mouse Events: They are triggered by clicking and releasing the mouse button or when the mouse cursor is over the Actor.
  • Touch Events: They are triggered by Touch Screens.
  • Custom Events: They are new events that we can create in the blueprints.
  • Event Begin Play: It is triggered when the game starts for the Actor.
  • Event Destroyed: It is triggered when the Actor is about to be removed from the game.
  • Event Tick: It is called every frame of the game. For example, if a game runs at 60 frames per second, this event will be called 60 times in a second.

There are more events in the "Input" category.

  • Action Events: Actions are mapped to keys or buttons. The event is triggered when those keys or buttons are pressed.
  • Axis Events: Axes are also mapped to keys or buttons and allows you to read intermediate values​​. It is useful to map analog sticks.
  • Gamepad Events: They are triggered by the players gamepads.
  • Key Events: There are events for all keys on a keyboard.
  • Mouse Events: This category contains a few more mouse-related events.

You can add many different events in a "EventGraph" but each event can only be added once in the "EventGraph".

The image below shows some examples of Events that have been added to the "EventGraph" but without any Action associated with them.

Next: Actions Overview in Blueprints
Prev: Class vs Objects in Blueprints
Table of Contents