Zerol Dev Notes

Appearance

Most skill cooldowns are quite simple to configure, and I don't want to manually create a separate GE for every simple case. Therefore, I wrote an asset action to automate the creation process.

The code is about 200 lines long and can serve as a template for other actions. Throughout this process, I learned a lot, and I will provide the complete code for this tools, hoping it will help you as well.

alt text

Idea ​

WARNING

Previous experience has shown that it's best not to dynamically create GE at runtime, so I opted to create them directly using Asset Action.

In the Gameplay Ability, define a cooldown time field, then right-click to find a custom action to automatically create a GE. In addition to creating the GE itself, a corresponding cooldown tag will also be created.

Editor Module ​

Since asset operations belong to the Editor Module, we need to create the Editor Module first.

  • Using Rider can greatly assist us in creating this. alt text

  • Add dependencies. alt text

Custom AssetDefinition ​

Originally, I used UAssetDefinitionDefault to implement the asset action, but comments indicated that this class is deprecated, and we need to use AssetDefinition.

At first, I directly used UGameplayAbility(Type) to create the AssetDefinition for it, but I found that UGameplayAbility(Assets Type) is actually a blueprint asset type, and blueprint assets are already implemented internally by the engine. Creating my own would override the internal implementation, which complicates things. Fortunately, I saw internal examples indicating that an AssetDefinition does not necessarily need to be implemented. You can refer to the implementation of [GameplayAbilityAudit].

Custom MenuExtension_xxx ​

namespace MenuExtension_YourActions

In this namespace, you only need to implement a method called Delayed Registration.

static FDelayedAutoRegisterHelper DelayedAutoRegister(EDelayedRegisterRunPhase::EndOfEngineInit, []

Implementation Details ​

There are two main details:

  • Creating the GE blueprint asset.

  • Creating a GameplayTag and saving it to an .ini file.

Creating GE ​

cpp
FAssetToolsModule& AssetToolsModule = FModuleManager::GetModuleChecked<FAssetToolsModule>("AssetTools");

First, obtain the AssetToolsModule.

cpp
UBlueprintFactory* BlueprintFactory = NewObject<UBlueprintFactory>();
BlueprintFactory->ParentClass = UGameplayEffect::StaticClass();
// do not use GE directly
// UGameplayEffect* NewGE = Cast<UGameplayEffect>(AssetToolsModule.Get().CreateAsset(CooldownGEName, NewGEPath, UGameplayEffect::StaticClass(), nullptr));
UObject* CreatedAsset = AssetToolsModule.Get().CreateAsset(CooldownGEName, NewGEPath, UBlueprint::StaticClass(), BlueprintFactory);

Create the GE blueprint asset; here, you need to use BlueprintFactory instead of directly using UGameplayEffect. Otherwise, you'll only get the default type of UGameplayEffect instead of its blueprint asset.

cpp
// GE Blueprint Asset Class
UClass* GeneratedClass = GE_Blueprint->GeneratedClass;
// use the CDO, not New Object
UGameplayEffect* NewGE = Cast<UGameplayEffect>(GeneratedClass->GetDefaultObject());

Next, obtain the GeneratedClass from the blueprint and its CDO to assign values to it using code.

Creating GameplayTag ​

You need to use IGameplayTagsEditorModule, so you must add dependencies. The usage is quite simple:

  • Check if the project allows creating GameplayTags via ini files.
    cpp
    const UGameplayTagsManager& Manager = UGameplayTagsManager::Get();
// Only support adding tags via ini file
if (Manager.ShouldImportTagsFromINI() == false)
{
    return;
}
  • Create a GameplayTag, with the default filename temporarily set to DefaultGameplayTags.ini.
    cpp
    const TSharedPtr<FGameplayTagNode> TagNode = Manager.FindTagNode(CooldownTagName);
if (!TagNode.IsValid())
{
    const FString TagComment = FString::Format(TEXT("Auto Gen Cooldown Tag for {0}"), {TagName});
    IGameplayTagsEditorModule::Get().AddNewGameplayTagToINI(TagName, TagComment, DefaultTagINI);
}

Complete Code ​

GamePlayAbilityGenCooldownGE

Other Attempts ​

Blueprint Editor Script ​

alt text

I can create a GE asset file, but I have not yet found a way to assign values. I don’t know how to use Set Editor Property; if anyone knows, please leave a comment.

alt text