Modifier Magnitude Calculation
Requirements
Blueprint parent class needs to be UGameplayModMagnitudeCalculation.
Override the functions CalculateBaseMagnitude, the equivalent of the CalculateBaseMagnitude_Implementation when done in C++.
Make sure to edit the Relevant Attributes to Capture in Class Defaults, with all the Attributes your calculation will need.
Calculation
Start implementing your calculation.
The built-in UGameplayModMagnitudeCalculation from the Engine already has a lot of BP exposed helpers. The Blueprint Attributes plugin doesn't need to add more (I'd just have to ensure calculation on BP defined Attributes are still working).
This includes:
- GetCapturedAttributeMagnitude()
- For this to work correctly, the Attribute needs to be added to the Relevant Attributes to Capture array.
- GetSetByCallerMagnitudeByName()
- GetSourceAggregatedTags()
- GetSourceActorTags()
- GetSourceSpecTags()
- GetTargetAggregatedTags()
- GetTargetActorTags()
- GetTargetSpecTags()
Warning for engine prior to 5.3
For engine prior to 5.3, you'll need to rely on a workaround for the issue of const methods. This is fixed in 5.3 and not required anymore.
By wiring in a pure const method that returns a reference to self for any BP exposed methods of MMC (like GetCapturedAttributeMagnitude)
Very important Make sure you name the return parameter something else than Self or self.
OK on the left, NOK on the right.
Example
SourceTags, TargetTags, CapturedWeight, CapturedFatigue, FatigueState, Result are all local variables.