> For the complete documentation index, see [llms.txt](https://docs.febucci.com/text-animator-unreal/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.febucci.com/text-animator-unreal/customization/create-your-own-effects/writing-custom-effects-c++.md).

# Writing Custom Effects (C++)

Other than using built-in effects and creating custom ones from the Editor, you can easily program custom Effects via C++.

***

{% hint style="warning" %}
Remember to add the Plugin module to your Project dependency to extend any Plugin class [Best Practices](/text-animator-unreal/other/best-practices.md#extending-plugin-c-classes)
{% endhint %}

## Effect Base Class <a href="#id-1-effect-base-class" id="id-1-effect-base-class"></a>

All you need to do is inherit from the base `UAnimationEffectBase` class.

```cpp
UCLASS(Blueprintable, EditInlineNew)
class TEXTANIMATORFEBUCCI_API UCustomEffect : public UAnimationEffectBase { ... }
```

There are also some useful classes already available for you that you can view from the API, like the `UBehaviorEffectBase` or `UAppearanceEffectBase` which are intended for each effect category, `UBehaviorEffectSine` which already handles modifiers such as “a, f, w” and more.

***

By inheriting from `UAnimationEffectBase`, you’ll find some methods to override, and in the docs (both Scripting API and in IDE) you’ll find more examples and info about new ones as well.

## Modifier Methods <a href="#id-3-modifier-methods" id="id-3-modifier-methods"></a>

Since effects can be affected by [Modifiers](about:/text-animator-unity/docs/how-to-add-effects-to-your-texts/#modifiers), you can override the following methods to handle them in your animations.&#x20;

These methods will be applied in the following order before the animation.

### ResetContext <a href="#id-31-resetcontext" id="id-31-resetcontext"></a>

```cpp
void ResetContext(UAnimTextBlock* Animator);
```

You can use this method to reset your animation’s variables to their initial state.

For example, in the details window you can publicly expose a variable called `BaseSpeed`, but in your effect only use `CurrentSpeed` and have that variable be `CurrentSpeed=BaseSpeed` inside this method.

### SetModifierTo <a href="#id-32-setmodifierto" id="id-32-setmodifierto"></a>

```cpp
void SetModifier(const FModifierInfo& Modifier);
```

You can use this method to apply a modifier to your variables.

For example this will multiply the `CurrentSpeed` value by the `s` modifier (if there is any).

```csharp
virtual void SetModifier_Implementation(const FModifierInfo& Modifier) override
{
    switch (Modifier.Name)
    {
        case "s": CurrentSpeed *= Modifier.Value; break;
    }
}
```

{% hint style="info" %}
To create a Behavior effect that has three modifiers such as “amplitude”, “frequency” and “waveSize”, you can create a class that inherits from `UBehaviorEffectSine` which will handle them for you.
{% endhint %}

## Animation Methods <a href="#id-4-animation-methods" id="id-4-animation-methods"></a>

Here are a few methods that you can override to create your custom animations.

### GetMaxDuration <a href="#id-41-getmaxduration" id="id-41-getmaxduration"></a>

The max duration of the effect. This is used to calculate the total duration of an animation and have smooth transitions, but if you have an effect that never ends you should return -1.

### CanApplyEffectTo <a href="#id-42-canapplyeffectto" id="id-42-canapplyeffectto"></a>

```cpp
bool CanApplyEffectTo(const FAnimTextGlyph& Glyph, UAnimTextBlock* Animator) const;
```

Used to check if the effect can be applied to the current letter. For example if you’re creating an appearance effect, which only applies if a character passed time is within the effect’s duration (but in that case you can inherit from `UAppearanceEffectBase` and have it handle that for you).

You can go beyond that, for example check if the character is a number or a letter, or their word index and much more.

### ApplyEffectOnParseTo <a href="#id-43-applyeffect" id="id-43-applyeffect"></a>

```csharp
void ApplyEffectOnParseTo(UPARAM(ref) FAnimTextGlyph& Glyph, UAnimTextBlock* Animator);
```

One-time function called when glyphs are first created. Useful if the effect has to perform one-time logic on the character, like initialization.

### ApplyEffectOnFrameTo

```csharp
void ApplyEffectOnFrameTo(UPARAM(ref) FAnimTextGlyph& Glyph, UAnimTextBlock* Animator);
```

Main function to apply an animation to a letter, called if “CanApplyEffectTo” returned true and executed once per frame.

`Glyph` holds all the information about the single character. It's passed by reference, which means you can directly modify it to animate it.&#x20;

For example, you may update its `Glyph.Offset` to move it around.

## ✅ Done! <a href="#done" id="done"></a>

**You’ve completed all the steps necessary, yay!**\
The more effects you add, the more this process will sound familiar and simpler.

{% hint style="warning" %}
Remember to create your effect `UDataAsset` in the Content Browser, and add it to a Database.

You can read more here: [Databases](/text-animator-unreal/effects/add-effects-to-your-texts/databases.md)
{% endhint %}

{% hint style="info" %}
👍🏻 You can always take a look at the Extra content to see an example of C++ customization!
{% endhint %}

**Have fun applying your effects!**