Attributes System Usage Guide

This guide details how to use the Advanced Attributes System in an Unreal Engine 5 project after integration. Developers will learn key workflows for modifying attributes, setting up regeneratable attributes, configuring associated attributes, creating custom extended attributes, and displaying attributes on the HUD. The guide also covers customization tasks to extend the system for project-specific needs, ensuring effective use in Action RPGs or similar genres.

Modifying Attributes

1. In the Blueprint of the actor with the BP_AttributesComponent, get a reference to the component.

2. Call ModifyAttribute to adjust an attribute’s current value:

   Get BP_AttributesComponent -> ModifyAttribute (AttributeTag: Attribute.Health, Value: -10)

3. Use dispatchers like OnAttributeValueModified to trigger other logic (e.g., updating UI or triggering abilities):

   BP_AttributesComponent -> OnAttributeValueModified -> Custom Event (Update HUD or Trigger Ability)

Setting and Retrieving Attribute Values

1. To set an attribute value directly:

   BP_AttributesComponent -> SetCurrentAttributeValue (AttributeTag: Attribute.Stamina, Value: 50)

2. To retrieve an attribute’s current value:

   BP_AttributesComponent -> GetCurrentAttributeValue (AttributeTag: Attribute.Stamina) -> Print String

3. Use other getter functions like GetBaseAttributeValue or GetMultiplierValue for specific needs.

Creating a Regeneratable Attribute

1. Define the attribute and its max counterpart in the Attributes array:
   • Add Attribute.MyNewAttribute (Base Value: 100).
   • Add Attribute.MyNewAttributeMax (Base Value: 100).
2. Create a new Blueprint class inheriting from BP_BaseRegeneratableAttribute (e.g., BP_MyNewRegeneratableAttribute).
3. In the new class’s Defaults:
   • Set ExtendedAttributeTag to Attribute.MyNewAttribute.
   • Set MaxAttributeTag to Attribute.MyNewAttributeMax.
   • Adjust RegenRate, RegenTickInterval, and RegenCoolDown as needed (e.g., RegenRate = 5, RegenTickInterval = 1).

4. Add the new extended attribute to the ExtendedAttributes array:
   • If standalone, add to the BP_AttributesComponent in the actor’s Details panel.
   • If using Advanced ARPG Combat, add to the PlayerInfoDataAsset or EnemyInfoDataAsset.

5. Add a WB_AttributeProgressBar to the HUD:
   • Set AttributeTag to Attribute.MyNewAttribute and MaxAttributeTag to Attribute.MyNewAttributeMax.
   • Initialize the progress bar in the HUD’s Event Graph (unless using Advanced ARPG Combat’s default HUD).

NOTE:

If using the included Combat Systems HUD (MainHUD), add your new attribute progress bar to the AttributeBarsVerticalBox and the attribute bar will be initialized for you. You MUST add your attribute bar to that vertical box before automatic initialization will work.

6. Test by modifying the attribute (e.g., subtract 25) and observing regeneration:

   InputAction IA_TestAttribute (Pressed) -> ModifyAttribute (AttributeTag: Attribute.MyNewAttribute, Value: -25)

Configuring Associated Attributes

1. In the Attributes array, select the governing attribute (e.g., Attribute.Endurance).
2. In the AssociatedAttributes map, add an entry:
   • Key: The governed attribute tag (e.g., Attribute.Stamina).
   • Value: A Curve Table row defining the relationship (e.g., a curve where X is Endurance value and Y is Stamina value).

3. Create or modify a Curve Table:
   • In the Content Browser, create a new Curve Table asset.
   • Add a curve row, adjusting values to define the relationship (e.g., linear increase or diminishing returns).

4. Test by modifying the governing attribute and checking the governed attribute’s value:

   ModifyAttribute (AttributeTag: Attribute.Endurance, Value: 10) -> GetCurrentAttributeValue (AttributeTag: Attribute.Stamina) -> Print String

Creating Custom Extended Attributes

1. Create a new Blueprint class inheriting from BP_BaseExtendedAttribute (e.g., BP_HealthExtendedAttribute).

2. Implement custom logic in functions like OnAttributeValueModified:

   OnAttributeValueModified -> If GetCurrentAttributeValue (Attribute.Health) <= 0 -> Trigger Death Ability

3. Add the new class to the ExtendedAttributes array in the BP_AttributesComponent or relevant data asset.

4. Test by modifying the associated attribute and verifying the custom logic triggers.

Troubleshooting

• Attributes Not Updating:
  • Verify AttributeTag exists in the Gameplay Tags table.
  • Ensure BP_AttributesComponent is initialized on Event BeginPlay.
• Regeneration Not Working:
  • Confirm BP_BaseRegeneratableAttribute is in ExtendedAttributes.
  • Check RegenRate and RegenTickInterval are non-zero.
• HUD Not Displaying:
  • Ensure WB_AttributeProgressBar is initialized with a valid BP_AttributesComponent.
  • Verify AttributeBarsVerticalBox is used for Advanced ARPG Combat’s MainHUD.
• Associated Attributes Not Scaling:
  • Check the Curve Table row is correctly assigned in the AssociatedAttributes map.
  • Verify the governing attribute’s value is being modified.

Best Practices

• Workflows:
  • Centralize attribute setup in PlayerInfoDataAsset or EnemyInfoDataAsset for consistency.
  • Use WB_AttributeProgressBar for essential attributes only to maintain clean HUDs.
• Pitfalls to Avoid:
  • Don’t use duplicate AttributeTag values in Attributes to prevent conflicts.
  • Avoid complex logic in OnAttributeValueModified to maintain responsiveness.
• Performance Considerations:
  • Minimize ExtendedAttributes per actor to reduce overhead.
  • Optimize AssociatedAttributes curves by avoiding overly complex calculations.
  • Disable bUpdateAttributeLerpBar for non-critical HUD attributes to improve performance.