CharFXTransform in Godot – Complete Guide

When diving into game development, mastering the fine art of text effects can elevate the way users interact with your game’s UI. Picture a fantasy RPG where each spell cast by a wizard animates the very letters of its incantation, or an adventure game where dialogue text shimmers with emotion. This isn’t just fancy decoration; it’s a way to create immersion, convey mood, and accentuate storytelling. Today’s tutorial zooms in on a powerful feature of the Godot engine – the CharFXTransform class – which lets you manipulate text in such magical ways within the RichTextEffect in Godot 4.

In the vibrant world of Godot 4, you have a toolkit at your disposal that can make your text come to life. Let’s explore what CharFXTransform has to offer, why it’s an asset worth learning, and how to use it to add a sprinkle of personality to your in-game text.

What Is CharFXTransform?

The CharFXTransform class in Godot 4 is a meticulous way to control how individual characters appear in a RichTextLabel node. It’s part of the engine’s larger UI system, which allows you to present text beyond static lines—text that can dance, fade, change colors, and more. By modifying the CharFXTransform properties, each character can become a living part of your scene, dynamic and responsive.

What Is It For?

CharFXTransform is integral for developers who want to create rich text effects without engaging in complicated post-processing or external animation software. It’s perfect for:

– Displaying dynamic dialogue in visual novels or RPGs
– Creating attention-grabbing UI elements like menus and score counters
– Making tutorial text that highlights actions for better gameplay clarity

Why Should I Learn It?

Engaging with CharFXTransform gives you the keys to a whole new domain of aesthetic delight and user engagement. Learning to manipulate text effects not only looks impressive, but it can also:

– Improve the user experience by providing visual cues or feedback
– Increase the expressiveness and atmosphere of your game’s narrative
– Differentiate your game from others with unique text animations

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Creating a Simple Color Change Effect

To begin with, we’ll implement a straightforward color change effect on individual characters within a RichTextLabel node. Here is how we create a new RichTextEffect resource.

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var t = char_fx.elapsed_time
	var speed = 2.0

	char_fx.color = Color(1, 1, 1, 1) * abs(sin(t * speed))
	return true

The `_process_custom_fx` function is where most of our magic happens. We use the `elapsed_time` property to create a pulsating sine wave effect, which in turn affects the color of the text.

Animating Character Position

We can animate the position of each character to create a wave-like motion. Here’s an example effect where characters float up and down independently:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var amplitude = 10
	var speed = 2.0

	char_fx.offset.y = sin(char_fx.absolute_index + char_fx.elapsed_time * speed) * amplitude
	return true

Adjusting the `offset` property of `char_fx` changes the character’s position, resulting in a wave of floating text that breathes life into your UI elements.

Fading Characters In and Out

To create a fade-in effect for each character, we can adjust their opacity over time. This creates an ephemeral quality, drawing the player’s attention as text appears out of thin air.

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var duration = 1.0
	var start_time = char_fx.absolute_index * 0.05

	char_fx.color.a = clamp((char_fx.elapsed_time - start_time) / duration, 0, 1)
	return true

This code example fades each character sequentially, based on their `absolute_index`, producing a cascading effect across the string of text.

Combining Effects for Dynamic Impressions

We can combine different transformations to create more sophisticated effects. Let’s combine the previous examples to create a color-changing, waving text that fades in:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var amplitude = 10
	var wave_speed = 2.0
	var color_speed = 2.0
	var fade_duration = 1.0
	var fade_start_time = char_fx.absolute_index * 0.05

	# Fade in effect
	char_fx.color.a = clamp((char_fx.elapsed_time - fade_start_time) / fade_duration, 0, 1)
	# Wave effect
	char_fx.offset.y = sin(char_fx.absolute_index + char_fx.elapsed_time * wave_speed) * amplitude
	# Color pulsating effect
	char_fx.color = Color(1, 1, 1, char_fx.color.a) * abs(sin(char_fx.elapsed_time * color_speed))

	return true

Here we have used the alpha value (`color.a`) to handle transparency, `offset.y` to move the characters vertically, and the `color` property to create a pulsating color effect.

When combining effects, it’s vital to consider the interactions between them, ensuring they produce a harmonious final result. Experimentation is key to achieving the desired outcome. Stay tuned for the next part of our tutorial where we will dive even deeper into crafting custom text effects!Manipulating character visibility is another impactful method to make your game’s text draw attention or mimic certain in-game dynamics. Here’s a simple effect that makes text randomly flicker, imitating an old, glitchy sign:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	char_fx.visible = randf() > 0.5
	return true

This code makes use of the `visible` property and `randf()`, a Godot function that returns a random floating-point number between 0 and 1, to randomly show and hide characters.

Let’s add a resizing effect to make our text zoom in and out slightly, which adds a dynamic layer of engagement:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var max_scale = 1.2
	var min_scale = 0.8
	var scale_speed = 2.0

	char_fx.scale = Vector2(1,1) * (min_scale + (max_scale - min_scale) * 0.5 * (1 + sin(char_fx.elapsed_time * scale_speed)))
	return true

In this example, we adjust the `scale` property of `char_fx` to smoothly transition the size of each character between `min_scale` and `max_scale`.

For a text that shivers with anticipation, or as if caught in a chilly breeze, we can add a small random offset to each character:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var shiver_intensity = 3.0

	char_fx.offset += Vector2(rand_range(-shiver_intensity, shiver_intensity), rand_range(-shiver_intensity, shiver_intensity))
	return true

Here, we modify the `offset` property by a small random Vector2 value, which makes each character shake slightly.

Creating an outline effect can enhance readability against complex backgrounds while adding a stylish appearance to your text. To achieve an outline, you need to effectively render the text multiple times with offsets:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var outline_color : Color = Color(0, 0, 0, 1)
	char_fx.outline_color = outline_color
	char_fx.outline_size = 1
	return true

The `outline_color` and `outline_size` properties of the `CharFXTransform` allow us to give each character a bold, crisp border.

Lastly, let’s consider how we might use a gradient effect to make the text color transition smoothly from one end to another:

extends RichTextEffect

var start_color : Color = Color(1, 0, 0, 1)  # Red
var end_color : Color = Color(0, 0, 1, 1)    # Blue

func _process_custom_fx(char_fx: CharFXTransform):
	var progress = char_fx.absolute_index / float(char_fx.visible_characters)
	char_fx.color = start_color.linear_interpolate(end_color, progress)
	return true

By using `linear_interpolate`, we blend two colors across the span of text, creating a visually pleasing gradient effect that’s relative to the `absolute_index` of each character.

Remember, all these effects can create a diverse range of emotional and visual impacts when used thoughtfully within your game’s context. With Godot’s CharFXTransform, your game’s UI won’t just deliver information; it will resonate with personality and style. Feel free to experiment with different combinations of these effects to discover what best suits the tone of your project. Keep learning, keep experimenting, and above all, keep creating engaging and immersive experiences for your players!Focusing on user engagement, let’s add an effect where characters pop into view with a bounce, similar to a bouncing ball. This gives a playful and energetic feel to the entrance of each character:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var gravity = -9.8
	var bounce_intensity = 50.0
	var start_time = char_fx.absolute_index * 0.1
	var time_since_start = max(char_fx.elapsed_time - start_time, 0)
	var position = 0.5 * gravity * pow(time_since_start, 2) + bounce_intensity * time_since_start

	if position < 0:
		char_fx.visible = false
		char_fx.offset.y += position

	return char_fx.visible

This code uses a basic physics formula to animate each character as if it were subject to gravity and initial upward velocity.

To help players follow along with a tutorial or draw attention to key information, we can highlight text character by character, as if it’s being typed out in real time:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var type_speed = 0.05
	char_fx.visible = char_fx.elapsed_time > char_fx.absolute_index * type_speed
	return true

This snippet relies on the `visible` property and gives the illusion that the text is being typed out at a defined speed.

Next, imagine text that reacts to an in-game event like an explosion. We can simulate a shockwave pushing the characters away from a central point:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var shockwave_center = char_fx.total_length / 2
	var distance_from_center = abs(char_fx.absolute_index - shockwave_center)
	var max_distance = char_fx.total_length / 2
	var shockwave_time_offset = 1.0
	var shockwave_speed = 5.0
	var offset = max_distance - min(distance_from_center, max_distance * (char_fx.elapsed_time - shockwave_time_offset) * shockwave_speed)
	char_fx.offset.x += (char_fx.absolute_index < shockwave_center ? -1 : 1) * offset
	return true

The `shockwave_center` and the character’s `absolute_index` are used to create a push effect on each character, with `elapsed_time` controlling the speed of the shockwave.

For narratively driven games, creating a heartbeat effect can add to dramatic scenes or enhance the story’s tension:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var heartbeat_speed = 1.0
	char_fx.scale = Vector2(1,1) * (1 + 0.05 * sin(char_fx.elapsed_time * heartbeat_speed * 2 * PI))
	return true

The scale is subtly adjusted by a sine wave to create a pulsating heartbeat effect, with `heartbeat_speed` determining the rhythm.

In addition to movement, we can also experiment with character rotation to both disorient and captivate the player, as can be seen in this swirling text effect:

extends RichTextEffect

func _process_custom_fx(char_fx: CharFXTransform):
	var swirl_intensity = PI / 4  # radians
	var swirl_speed = 2.0
	char_fx.rotation_degrees = sin(char_fx.elapsed_time * swirl_speed + char_fx.absolute_index) * swirl_intensity
	return true

We modulate the `rotation_degrees` property to create a swirling motion, giving the text an almost hypnotic quality.

Lastly, we might want the text color to react and change based on the player’s health in a game. For instance, moving from green to red as health decreases:

extends RichTextEffect

var health_percentage = 1.0  # 100% health

func _process_custom_fx(char_fx: CharFXTransform):
	var healthy_color: Color = Color(0, 1, 0, 1)  # Green
	var critical_color: Color = Color(1, 0, 0, 1)  # Red
	char_fx.color = healthy_color.linear_interpolate(critical_color, 1 - health_percentage)
	return true

The color interpolation changes as the `health_percentage` variable adjusts, reflecting the player’s status through the text color.

Together, these code snippets offer a variety of effects that can bring complexity and dynamism to your game’s text. We at Zenva encourage you to modify, combine, and expand upon these examples to fit the unique style and atmosphere of your own game projects. Remember that text is more than just information; it’s an extension of your game’s world, capable of telling a story all on its own.

Where to Go Next in Your Game Development Journey

After delving into the captivating world of text effects with Godot 4, you might be eager to learn more and sharpen your game development skills further. That’s why we’ve crafted the Godot Game Development Mini-Degree, a comprehensive suite of courses that will take you from beginner to adept in the art of game creation using Godot 4. Whether you aspire to craft immersive 2D platformers, strategize within the realms of RTS, or innovate with intricate RPG mechanics, our project-based curriculum provides a deep dive into all things Godot, equipping you with the knowledge to bring your game concepts to life.

To expand your expertise across a broader spectrum of Godot’s capabilities, we invite you to explore our array of Godot courses. Structured for both novices and seasoned developers alike, these project-based courses are available 24/7, enabling you to progress at a pace that suits your learning style and lifestyle. As you master new concepts and real-world applications, you will amass a portfolio that not only demonstrates your newfound prowess but also propels you towards your career and creative aspirations.

Embark on your next adventure with Zenva – where learning meets possibility, and every line of code brings you closer to realizing your vision as a game developer.


The literary alchemy of Godot’s CharFXTransform has the power to turn static text into an interactive canvas, enabling you to weave a richer tapestry of player experience. As you’ve seen, these effects are not just for show; they play a critical role in enhancing the player’s immersion and emotional connection to the game. By bringing letters to life, you’re not just instructing or informing—you’re enchanting.

We at Zenva are excited to see how you’ll use these techniques to innovate and inspire within your own game worlds. If you’re ready to take your skills to the next level, don’t hesitate to check out the Godot Game Development Mini-Degree and continue your journey with us. Together, let’s build unforgettable experiences and chart new territories in the realm of game development.

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