Add Combat

Complete Add Movement first. This chapter gives the Soldier 100 health and an attack that deals 3 damage at 10 shots per second (600 RPM). Hits apply immediately; the animation remains the locomotion graph you already built.

1. Create health and weapon components

In Content/Demo/Blueprints, right-click and choose SeinARTS Entity Component. Name the asset SC_DemoHealthComponent. Open it and add these variables in My Blueprint:

Variable	Type	Default
Health	Fixed Point	100
MaxHealth	Fixed Point	100

Make the variables Instance Editable so each entity can author its values. Compile to expose their defaults, enter the values, and save. The component compiler creates its simulation data struct; you do not create a separate Structure asset.

Create another SeinARTS Entity Component, SC_DemoCombatComponent, with Instance Editable variables:

Variable	Type	Default
Damage	Fixed Point	3
RateOfFire	Fixed Point	10

RateOfFire means shots per simulation second. Compile and save.

Open SU_Soldier and add both components. Compile and save.

These values give 30 damage per second. A target with 100 health takes 34 hits to defeat, approximately 3.3 seconds from the first hit with uninterrupted fire.

2. Create the attack ability

In Content/Demo/Blueprints, create a SeinARTS Ability with Generic Ability as its parent. Name it SA_Attack.

Set its Class Defaults:

Field	Value
Ability Name	Attack
Target Type	Entity
Max Range	500
Out Of Range Behavior	Auto Move Then
Requires Line Of Sight	Enabled
Granted Tags	SeinARTS.Ability.Attack
Cancel Abilities With Tag	SeinARTS.Ability

The generated Ability Tag is SeinARTS.Ability.Attack. Automatic movement uses the Soldier’s Movement Ability to approach an initially distant target. The attack graph will check range again before every hit.

Add a Fixed Point variable named TimeUntilShot. On Event On Activate, set it to 0. This resets the timer whenever a new attack starts.

3. Read the simulation components

Create a function in SA_Attack named TryShot. This function performs one hit attempt and contains no latent nodes.

Use the framework’s typed component getter for SC_DemoCombatComponent’s generated data struct, with Entity Handle = Owner Entity. Find it by searching the graph menu for your component’s name. Break the returned struct to read Damage and RateOfFire. Use the getter’s success output to branch; on failure, call End Ability and return.

Use the corresponding typed getter for SC_DemoHealthComponent on Target Entity. On failure, end the ability. Cache its Health output in a local Fixed Point variable named OldHealth before changing anything.

If Damage or RateOfFire is zero or negative, or OldHealth is zero or negative, end the ability and return. Use Fixed Point comparison and arithmetic nodes by dragging from these pins.

Component getters read simulation data. Do not use Get Component by Class on a rendered actor to read live health.

4. Check the target

In TryShot, add Make Sein Target Query and configure:

Input	Value
Instigator	Owner Entity
Range	Max Range
Required Component	Generated data struct for SC_DemoHealthComponent

The query uses the attacker’s current simulation position, checks a full circle and requires line of sight. The default scorer rejects targets owned by the attacker.

Connect the query and Target Entity to Check Target. Switch on its result. Continue only on Eligible; every other result calls End Ability. In this demo, an attack ends if its target escapes range or sight. A new attack order approaches it again.

5. Apply a hit

On Eligible, call Apply Field Delta:

Input	Value
Entity Handle	Target Entity
Struct Type	Generated data struct for SC_DemoHealthComponent
Field Name	Health
Delta	0 - Damage, using Fixed Point subtraction
Clamp Min	Enabled

Branch on the return value. Failure ends the ability. On success, calculate OldHealth - NewValue and pass that amount to Notify Damage Applied, with Target = Target Entity and Source = Owner Entity.

Branch on At Min:

• True: call Notify Death with Dying = Target Entity and Killer = Owner Entity, then Destroy Entity on Target Entity, then End Ability.
• False: return from TryShot.

Keep the notification nodes before Destroy Entity. They supply presentation events; the health write and Destroy Entity perform the gameplay changes.

6. Run the firing timer

Use the supplied Event On Tick, whose Delta Time is Fixed Point simulation time:

1. Set TimeUntilShot = TimeUntilShot - Delta Time.
2. If TimeUntilShot is greater than zero, finish this tick.
3. Otherwise call TryShot.
4. Check the inherited Is Active value. If the shot ended the ability, finish this tick.
5. Read RateOfFire from Owner Entity’s combat data again. Set TimeUntilShot = TimeUntilShot + (1 / RateOfFire).

Use a Fixed Point 1 for the division. At the authored rate this gives a 0.1-second firing interval, carrying the fraction of time left over between simulation ticks. Do not use an Unreal Timer, Delay, or Event Tick for this loop.

Compile and save SA_Attack.

7. Grant and map Attack

On SU_Soldier’s Sein Abilities, add SA_Attack to Granted Abilities. Keep SA_Move.

Add a Default Commands entry with Required Context containing both SeinARTS.Command.Context.RightClick and SeinARTS.Command.Context.Target.Enemy, Ability Tag SeinARTS.Ability.Attack, and Priority 10.

Compile and save. Enemy clicks now select Attack; ground clicks still select Move.

Checkpoint

• The Soldier authors health and weapon values through two entity components.
• Attack validates its target and reduces Health through Apply Field Delta.
• Its timer uses fixed simulation time and resets on each activation.
• A lethal hit notifies presentation, destroys the target, and ends the ability.

The next chapter creates a neutral mineral deposit that exercises the same hit loop and gives you an immediate income test. The later lobby chapter supplies the second human player for an enemy-versus-enemy test.

Continue with Add Mineral Income.