Overview #

The weapon system allows you to use and manage different weapons in the game effectively. It consists of two main parts: the Weapon System Component and the Weapon Component. The Weapon System Component handles overall weapon management, including switching weapons and firing mechanics, while the Weapon Component defines the specific behaviors and characteristics of each weapon

Weapon System Component #

The Weapon System Component is the central part of the weapon management system. It handles weapon registration and controls weapon selection, enabling players to switch between different weapons. This component also manages firing actions, including aim-down-sights functionality.

Note: To get started with weapon system components, you can either create a custom component from scratch, or you can refer to the Demo Weapon System Component Blueprint provided in the project. You can find the it here:

Create a Weapon System Component Blueprint #

In Unreal Engine, go to Content Browser > Right-click > Blueprint Class.

Select EDWeaponSystemComponent as the parent class.

Open the newly created actor and configure it’s values in the Class Defaults section.

Handle Input #

For the weapon system component to work you need to set up it’s input functions:

• Cycle Weapons: This function will cycle through the weapons as the name suggests, You can bind it to an InputAxis node and assign it’s axis value to the direction.
• Fire Input: This function tells the component whether the fire button is pressed or not, Allowing you to set-up custom inputs for the fire mechanism. You can bind it to an InputAction node as shown in the image below.

Register Weapon Components #

In order to add weapons to your Weapon System Component you need to create and register them inside a specific event/function called Create Weapons.

To do that, First override the Create Weapons function in your blueprint.

This will add an event in the Event Graph called Event Create Weapons which you can then use to register your weapons.

If you’re like me and prefer to use it as a function instead, you can Right Click the node and select Convert event to function.

Navigate into the CreateWeapons function and register your first weapon by following these steps:

• Create a new instance of your Weapon Component using the Add Component by Class node with the desired weapon component class.
• Make sure You pass Get Owner to the Target input so that it belongs to the same character in which the Weapon System Component does.
• Also Make sure you pass Self to the Weapon System input so that the Weapon Component knows what System it belongs to.
• Finally, Register the weapon component using the Register Weapon Component node, providing it with a unique identifier and whether it’s in rapid fire mode.
  You can use Unique Identifier to select this weapon using the Select Weapon node later on.

Add It to Your Character #

Navigate to your character blueprint and add the Weapon System Component that you created in the last section.

Select the newly added component and set-up it’s values in the Details Panel if needed.

Use the Set Fire Origin node to tell the component where the Fire Origin is located so that it can fire from that location.

Weapons only fire in ADS mode, so make sure you correctly set it up using the Set ADS node.

For example, here is the Set ADS logic implemented in the ALS_AnimMan_CharacterBP character blueprint which only allows ADS when it’s not in Ragdoll mode.

This is the reason why it’s implemented in the character rather than the Weapon Component System like the function Fire Input.

Selecting a Specific Weapon #

You can select a specific weapon using it’s registered Unique Identifier explained in the previous steps using the Select Weapon node.

You can call this node where-ever you have access to the Weapon System Component.
For example, In this image we are selecting the weapon registered above inside of the character blueprint.

Getting the Current Weapon #

You can retrieve the currently selected weapon using the Get Current Weapon Validated node.

If there is currently a weapon selected it will return it and continue with the Valid execution pin, otherwise it will return an empty struct and continue with the Invalid execution pin.

The WeaponType struct includes the Weapon Component, Unique Identifier, and IsRapid values.

Handle ADS Events #

You can implement ADS events on the Weapon System Component to provide customized logic for when ADS happens.

Disabling the Weapon system Component #

You can Enable and Disable the Weapon System Component using the Set Enabled node.

While disabled, the weapon system component doesn’t respond to events and doesn’t update it’s internal state.

Upon being disabled the weapon system component will Deselect the currently selected weapon.

Weapon Component #

The Weapon Component represents a specific weapon in the game. This component handles the firing logic, allowing for custom weapon implementation.

Create a Weapon Component Blueprint #

In Unreal Engine, go to Content Browser > Right-click > Blueprint Class.

Select EDWeaponComponent as the parent class.

Open the newly created actor and configure it’s values in the Class Defaults section.

The Name variable is an arbitrary variable which you can use to display weapon information on HUD.
In the Demo it’s used in the Get HUD Text function of the BP_Weapon_Base blueprint.

Note: The IsRapid variable is not defined as an instance editable variable on the Weapon Component instead it’s exposed on the Register Weapon Component allowing the same component being registered multiple times with different IsRapid and Unique Identifier variables. You can however read it’s value in the blueprints.

Handle Weapon Selection #

The Selected event triggers when this weapon is selected via cycling, a Select Weapon call, or when the Weapon System Component is enabled by a Set Enabled call.

Similarly, The Deselected event triggers when another weapon is selected via cycling or a Select Weapon call, or when the Weapon System Component is disabled by a Set Enabled call.

Handle Fire Logic #

The Fire event serves as the main point to handle your fire logic. There are additional events that give you the flexibility to customize your weapons.

The Begin Fire event triggers right before the weapon starts warming up. The Tick Fire event is also triggered during the warmup phase. To determine if a weapon is in warmup, you can use the Is In Warmup node.

Handle ADS Logic #

Similar to Weapon System Component, You can implement ADS events on the Weapon Component as well to provide customized logic for when ADS happens.

For example, if you want to play a sound when player Aims and it’s specific to this weapon type, the Begin ADS event is the perfect place to spawn the Sound.

Using Trace Weapons in the Demo #

When using our demo weapon system, weapons that utilize trace mechanics, such as Beam and Instant weapons, do not automatically penetrate static mesh components or foliage blueprints. They will only penetrate these objects and hit the objects behind them if they have the BeamPenetrable actor tag.
Furthermore, The trace weapons don’t account for hit objects with components that ignore the BlockedBullet collision response channel.

These functionalities are defined in the Apply Trace Damage function of the BP_Weapon_Base blueprint, which is used in the Beam and Instant weapons.