Casts

Cast Ability

The Cast Ability can be configured in many ways to support different design goals. Below is a property summary, followed by details on supported triggers, targeting options, and commit timings.

Cast Requests

Similar to the Combat Ability, that uses Melee Scans and Projectile Requests as data transfer objects, the Cast Ability uses Cast Requests for the same purpose.

Cast Requests are usually sent by the Cast Notify and are received by the ability as the payload in the Gameplay Event identified by Combat.Event.Cast.

Executing a Targeting Preset to Apply Damage

Let's begin exploring usage scenarios for the Cast Ability, starting with the most straightforward one: collecting targets using a preset and applying damage. This is usually enough for abilities such as buffs and debuffs.

Configure the Targeting Preset

1. Create a new Data Asset based on TargetingPreset.

2. Add a Targeting Task to select actors in an area, using a capsule shape with a radius of 500. Use the CombatObject collision channel.

3. Add a Filter Task to exclude actors that do not match your base actor class or type.

4. Add another Filter Task to remove actors that are already dead.

Create the Damage Effect

1. Create a Gameplay Effect extending from GameplayEffect.

2. Add a Modifier that increases the Pending Damage attribute.

3. Add CombatExecution_Damage to the list of Executions.

4. In the Execution section, add a Modifier that multiplies the Base Damage by 2.0, or any value you prefer.

Create the Cast Ability

1. Create a Gameplay Ability extending from CombatAbility_Cast.

2. Set the Cast Trigger to Gameplay Event.

3. Assign the Gameplay Effect you created as the Cast Effect Class.

4. Set Targeting to Targeting System, and assign the Targeting Preset created earlier.

5. Assign the Animation Montage that includes the Cast Notify as the Default Animation.

If you execute this ability in-game, it should apply the configured Gameplay Effect to all valid targets around the player, based on the criteria defined in your Targeting Preset.

Spawning a Cast Actor to Apply Damage

The next usage scenario covers spawning a Cast Actor that uses its physical presence in the world to collect targets and apply a Gameplay Effect. This is useful for abilities where damage is applied by a spawned actor, such as a "Black Hole", "Tornado", or similar effect.

Actors used by the Cast Ability must implement the CombatCastInterface. Ninja Combat provides a base implementation, NinjaCombatCastActor, which you can extend to create your own Cast Actors.

Create the Cast Actor

1. Create an Actor extending from NinjaCombatCastActor.

2. Add any visuals you like, such as a Static Mesh, Niagara Effects, or Audio Components.

3. Adjust the size of the built-in Sphere Collision and configure it to act as a Combat Collider.

Create the Cast Ability

1. Open the Cast Ability previously created (or a duplicate of it), and set Targeting to Spawn Actor.

2. Assign your Cast Actor to the Cast Actor Class.

If you execute this ability in-game, it should spawn your Cast Actor and apply the configured Gameplay Effect to all valid targets detected by the actor’s collision settings.

Selecting the Spawn Location for the Cast Actor

Now let’s take the Cast setup one step further by introducing a Gameplay Ability Target Actor.
The Gameplay Ability System uses actors based on GameplayAbilityTargetActor to handle targeting logic.

The result of this targeting process can be either a group of actors or a location, depending on the Targeting Mode set on the Cast Ability.

• When set to Wait for Confirmation, the Target Actor provides a list of targets.

• When set to Wait for Confirmation and Spawn Actor, the Target Actor provides a location, which is used to spawn the Cast Actor.

Create the Cast Ability

1. Open the Cast Ability previously created (or a duplicate of it), and set Targeting to Wait for Confirmation and Spawn Actor.

2. In the Targeting Actor Class, select the Ability System Targeting Actor you want to use.

3. Configure your input system to call LocalInputConfirm on the owner's Ability System Component when confirming the target.

If you execute this ability in-game, it will spawn your Targeting Actor according to your configuration.

Once the target location is confirmed, the ability will spawn your Cast Actor and apply the configured Gameplay Effect to all valid targets detected through its collision settings.

Cast Interface

Any actor meant to be used with casting must implement CombatCastInterface. It defines the source responsible for spawning the actor (e.g. the combatant), the Gameplay Effect Handle applied and the main execution function.

Cast Actor

Cast Actors are commonly used during casting. They are created by the Cast Gameplay Ability (or another ability) and contain a pre-generated Gameplay Effect that is applied to targets they collect—typically via collision.

The base Cast Actor includes the following properties:

In addition to the required interface functions, the base Cast Actor provides the following helpers:

The example above illustrates a typical implementation:

1. Extends the StartCast function and calls the logic from parent.

2. Sets the Cast Actor’s location to match the owner’s shield, retrieved via GetWeapon.

3. Binds an event to the Particle System and resets (then activates) the Niagara Component.

4. Resets and activates the Audio Component.

5. When the particle effect completes, the actor is deactivated and returned to the pool.

Actor Pooling

Cast Actors and Targeting Actors and are good candidates for Actor Pooling. This helps reduce the cost of spawning and garbage collecting these actors when they are frequently used in the game.

Both actors are Poolable Actors, ready to be used in conjunction with the Actor Pool provided by Ninja Combat. For more information on enabling the pool and registering your Cast Actor, check the Actor Pool page.