VisualShaderNodeParameter in Godot – Complete Guide

Welcome to our tutorial on the VisualShaderNodeParameter class in Godot 4. This class is a cornerstone in the creation of visually stunning shaders within the Godot game engine. As you embark on this journey, you’ll discover the exciting potential of visually programming your own shaders, integrating them into your games, and harnessing the power of Godot’s rendering engine. Whether you’re a beginner looking to dive into game development or an experienced coder aiming to expand your skill set, mastering VisualShaderNodes can amplify your creative capabilities. This six-part guide will walk you through the use of VisualShaderNodeParameters with clear examples focused on game development concepts. Let’s unlock the magic of visual shader programming together!

What Are VisualShaderNodeParameters?

VisualShaderNodeParameters are the building blocks of shader graphics in Godot. They provide the mechanism for setting variables externally, which means these variables can be adjusted within the ShaderMaterial. This unlocks a new realm of dynamic visuals where game environments and characters can be transformed based on gameplay or player input.

What Are They Used For?

These parameters serve a critical role in making your shaders more interactive and adaptable. For instance, you can utilize them to change the texture’s appearance on a game character, to adjust the light intensity in a scene, or to create complex animations. By modifying shader parameters, you create an immersive experience, adding depth and realism to your in-game worlds.

Why Should I Learn About VisualShaderNodeParameters?

Understanding and utilizing the VisualShaderNodeParameter class can significantly elevate your game development skills. Here’s why you should consider learning about them:

– **Flexibility:** Shader parameters allow for real-time visual adjustments without editing shader code directly.
– **Efficiency:** It permits non-technical team members such as artists to tweak visual effects from the inspector.
– **Enhanced Creativity:** You’ll open the doors to innovative visual effects that can set your game apart.
– **Control:** Gain the ability to manipulate visuals programmatically for more dynamic and reactive game mechanics.

Embracing this knowledge will not only enhance the visual appeal of your games but will also streamline your development process. Join us as we delve into the exciting world of visual shaders in Godot 4.

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Creating a Basic VisualShaderNodeParameter

In this section, we’ll create a simple VisualShaderNodeParameter and link it to a shader material. It will serve as the foundation for our upcoming examples. First, let’s start with creating a basic shader parameter that controls the albedo color of a material.

var shader_material = ShaderMaterial.new()
var visual_shader = VisualShader.new()
var color_parameter = VisualShaderNodeParameter.new()

color_parameter.parameter_name = "AlbedoColor"
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, color_parameter, Vector2(100, 150))

shader_material.shader = visual_shader

In the code above, we’ve created a new ShaderMaterial, added a VisualShader, and then created a VisualShaderNodeParameter named ‘AlbedoColor’. We then add this node to our visual shader and assign the visual shader to our ShaderMaterial.

Connecting Shader Parameters to Input Nodes

After setting up your VisualShaderNodeParameter, the next step is to connect it to input nodes for it to affect the shader’s output.

var input_node = visual_shader.get_graph_edit().connect_nodes(
    color_parameter.get_output_port(0),
    my_shader_material.get_input_port(0)
)

Here, we are connecting the output port of our ‘color_parameter’ to the input port of ‘my_shader_material.’ Now the parameter we created can influence the material shader directly.

Adjusting Shader Parameter Properties

Shader parameters come with properties that can be adjusted for different effects. Below is an example of how to modify the properties of our previously created albedo color parameter to make it a vec4 type with a default color value.

color_parameter.parameter_type = VisualShaderNodeParameter.TYPE_VEC4
color_parameter.default_value = Color(1, 0, 0, 1)  // Red color

By setting the ‘parameter_type’ to TYPE_VEC4, we have defined our parameter as a vector with four components (RGBA in this case), and we have given it a default red color.

Using VisualShaderNodeParameter in a Shader Script

Now that we have our parameter set up, let’s see how we can use it in an actual shader script.

// Assign the shader script to the ShaderMaterial
var shader_code = """
shader_type spatial;
render_mode unshaded;

uniform vec4 AlbedoColor;

void fragment() {
    ALBEDO = AlbedoColor.rgb;
}
""";

shader_material.set_code(shader_code)

The shader script sets the shader type to spatial and makes it unshaded. It then defines a uniform variable ‘AlbedoColor,’ which corresponds to our VisualShaderNodeParameter. In the fragment function, it assigns the AlbedoColor to the ALBEDO output, which determines the pixel color.

By embedding VisualShaderNodeParameters into shader scripts like this, you gain fine control over how your materials look and feel in the game. Experiment with setting different default values and connecting various nodes to see the range of visuals you can create. Stay tuned for the next part, where we will further explore the versatility of VisualShaderNodeParameter with more complex examples.Great! Let’s take visual shader parameters a step further. In this section, I’ll demonstrate additional uses with further examples, inching closer toward creating more dynamic and visually compelling materials in Godot.

Animating Shader Parameters

A common use case for shader parameters is to animate visual properties over time. Here’s how to animate the ‘AlbedoColor’ using the ‘TIME’ built-in uniform variable.

// Modulate the red color value with time
var shader_code = """
shader_type spatial;
render_mode unshaded;

uniform vec4 AlbedoColor;

void fragment() {
    float time_sin = sin(TIME) * 0.5 + 0.5; // Oscillates between 0 and 1
    vec4 animated_color = vec4(time_sin, AlbedoColor.g, AlbedoColor.b, 1.0);
    ALBEDO = animated_color.rgb;
}
""";

shader_material.set_code(shader_code)

In this example, we modulate the red component of ‘AlbedoColor’ based on the sine of the elapsed time, creating an animation that oscillates between various intensities of red.

Linking Parameters to External Events

What if we want to link our shader parameter to a game event, such as a player’s health depleting? Let’s set up a VisualShaderNodeParameter that changes color based on the player’s health.

// Set up a parameter node for health-based color
var health_parameter = VisualShaderNodeParameter.new()
health_parameter.parameter_name = "HealthColor"
health_parameter.parameter_type = VisualShaderNodeParameter.TYPE_VEC4
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, health_parameter, Vector2(100, 200))

// Assume a function that updates health
func update_health(health_float: float) -> void:
    shader_material.set_shader_param("HealthColor", Color(1.0, health_float, health_float, 1.0))

By calling `update_health()` and passing a normalized health value, the ‘HealthColor’ parameter is updated, visually indicating the player’s health within the game through color change.

Combining Parameters for Complex Effects

You can combine multiple VisualShaderNodeParameters to craft complex visual effects. Suppose we want a material that not only changes its albedo based on health but also pulsates over time to indicate critical health levels. Let’s blend our ‘AlbedoColor’ and ‘HealthColor’ parameters together.

// Blend the Albedo and Health colors with time
var time_node = VisualShaderNodeTime.new()
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, time_node, Vector2(200, 150))

var sine_node = VisualShaderNodeScalarFunc.new()
sine_node.function = VisualShaderNodeScalarFunc.FUNC_SIN
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, sine_node, Vector2(300, 150))

visual_shader.get_graph_edit().connect_nodes(time_node.get_output_port(0), sine_node.get_input_port(0))

var blend_node = VisualShaderNodeVectorInterp.new()
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, blend_node, Vector2(400, 200))

visual_shader.get_graph_edit().connect_nodes(color_parameter.get_output_port(0), blend_node.get_input_port(0))
visual_shader.get_graph_edit().connect_nodes(health_parameter.get_output_port(0), blend_node.get_input_port(1))
visual_shader.get_graph_edit().connect_nodes(sine_node.get_output_port(0), blend_node.get_input_port(2))

shader_material.shader = visual_shader

We’ve added a `VisualShaderNodeTime`, `VisualShaderNodeScalarFunc` to get the sine of time, and a `VisualShaderNodeVectorInterp` to interpolate between ‘AlbedoColor’ and ‘HealthColor’. The rate of pulsation is controlled by the sine of time, creating a heart-beat-like effect on materials when the player’s health is critical.

Adjusting Parameters In Response to User Input

Shader parameters can also be adjusted in real-time in response to player input. For example, let’s create a VisualShaderNodeParameter that alters the material’s emission based on a button press.

// This can be called when the player presses a button to increase emission
func on_button_press() -> void:
    var emission_strength = shader_material.get_shader_param("EmissionStrength") as float
    emission_strength += 0.1  // Increase emission strength
    shader_material.set_shader_param("EmissionStrength", emission_strength)

The function `on_button_press()` simply increases a float parameter named ‘EmissionStrength’. This could be tied to in-game events, such as the player picking up an object that causes them to glow.

Playing with shader parameters like this can greatly increase the depth of visual storytelling in your games. Harness the power of visual shader parameters to breathe dynamic and reactive life into your game’s visuals. Stay creative and keep experimenting with the vast possibilities VisualShaderNodeParameters provide in Godot.Great! Moving forward, let’s explore even more advanced applications of VisualShaderNodeParameters in Godot, bringing nuanced visual flair to your games.

Let’s consider creating a shader that simulates environmental influences, like wind or water flow, on a surface using a parameter to control the distortion effect.

// Create a parameter node for distortion strength
var distortion_parameter = VisualShaderNodeParameter.new()
distortion_parameter.parameter_name = "DistortionStrength"
distortion_parameter.parameter_type = VisualShaderNodeParameter.TYPE_FLOAT
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, distortion_parameter, Vector2(100, 250))

// Time node to animate over time
var time_node = VisualShaderNodeTime.new()
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, time_node, Vector2(200, 250))

// Sine wave node to use for distortion effect
var sine_node = VisualShaderNodeScalarFunc.new()
sine_node.function = VisualShaderNodeScalarFunc.FUNC_SIN
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, sine_node, Vector2(300, 250))
visual_shader.get_graph_edit().connect_nodes(time_node.get_output_port(0), sine_node.get_input_port(0))

Using this setup, we can now create a distortion effect by adjusting the ‘DistortionStrength’ parameter based on wind strength or water speed, potentially changed by in-game events or environmental triggers.

Let’s further expand on this by making the distortion animated over time and dependent on the shader’s UV coordinates:

// Connect the distortion to UV coord and time
var uv_node = VisualShaderNodeUV.new()
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, uv_node, Vector2(200, 300))

var add_node = VisualShaderNodeVectorOp.new()
add_node.operation = VisualShaderNodeVectorOp.OPERATION_ADD
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, add_node, Vector2(400, 300))

visual_shader.get_graph_edit().connect_nodes(uv_node.get_output_port(0), add_node.get_input_port(0))
visual_shader.get_graph_edit().connect_nodes(sine_node.get_output_port(0), add_node.get_input_port(1))

var text_node = VisualShaderNodeTexture.new()
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, text_node, Vector2(500, 300))

// Assume a texture is already loaded
var pattern_texture = preload("res://pattern.png")
text_node.texture = pattern_texture
visual_shader.get_graph_edit().connect_nodes(add_node.get_output_port(0), text_node.get_input_port(0))

// Connect the texture node to output color
var output_node = VisualShaderNodeOutput.new()
visual_shader.add_node(VisualShader.TYPE_FRAGMENT, output_node, Vector2(600, 300))
visual_shader.get_graph_edit().connect_nodes(text_node.get_output_port(0), output_node.get_input_port(0))

shader_material.shader = visual_shader

In this shader, the texture is distorted based on the UV coordinates altered by the sine wave function. The intensity of this distortion can be modified using the ‘DistortionStrength’ parameter.

Now, imagine we want to change the appearance of our material in response to light intensity in the scene. We can create a parameter that allows us to set the amount of ‘glow’ a material has when under strong lighting:

// Parameter for glow control
var glow_parameter = VisualShaderNodeParameter.new()
glow_parameter.parameter_name = "GlowAmount"
glow_parameter.parameter_type = VisualShaderNodeParameter.TYPE_FLOAT
visual_shader.add_node(VisualShader.TYPE_LIGHT, glow_parameter, Vector2(100, 400))

// Light node to get light information
var light_node = VisualShaderNodeLight.new()
visual_shader.add_node(VisualShader.TYPE_LIGHT, light_node, Vector2(200, 400))

// Mix node to combine glow based on light
var mix_glow_node = VisualShaderNodeVectorMix.new()
visual_shader.add_node(VisualShader.TYPE_LIGHT, mix_glow_node, Vector2(300, 400))
visual_shader.get_graph_edit().connect_nodes(light_node.get_output_port(0), mix_glow_node.get_input_port(0))
visual_shader.get_graph_edit().connect_nodes(glow_parameter.get_output_port(0), mix_glow_node.get_input_port(1))
visual_shader.get_graph_edit().connect_nodes(mix_glow_node.get_output_port(0), output_node.get_input_port(0))

shader_material.shader = visual_shader

With this setup, our material’s “glow” increases proportionally with the light intensity hitting it, creating a material that feels more alive and responsive to the game world’s lighting conditions.

Finally, let’s look at a case where we want the player’s power level to influence a visual effect on their avatar. We might want to change not just the color, but also the emission and even the texture detail based on power level:

func update_power_level(power_level: float) -> void:
    shader_material.set_shader_param("PowerGlow", max(power_level, 1.0))
    shader_material.set_shader_param("PowerColor", Color(power_level, 0.0, 1.0 - power_level, 1.0))
    shader_material.set_shader_param("TextureDetail", clamp(power_level, 0.0, 1.0))

Invoking `update_power_level` function could change our avatar’s shader properties, creating a powerful visual cue that communicates the character’s strength to the player.

These examples only scratch the surface of what’s possible with VisualShaderNodeParameters in Godot. With them, your creative vision becomes virtually limitless as you manipulate and enhance your game world’s visuals on-demand.

Continuing Your Journey in Game Development

Embarking on the journey of mastering the Godot engine and its VisualShaderNodeParameters is just the beginning. As you continue to hone your skills, you might be wondering what’s next. If you’re eager to broaden your game development expertise and create your own cross-platform games using Godot 4, our Godot Game Development Mini-Degree is the perfect next step for you.

With a comprehensive curriculum that covers a wide range of topics — from using assets and mastering GDScript to designing gameplay control flows and building distinct game mechanics for various genres — our Mini-Degree is tailored for both beginners and seasoned developers. You can jump right into the areas that intrigue you the most or start from the basics to build a solid foundation.

For those who want to explore more, visit our broad collection of Godot courses. Each course is packed with interactive lessons, coding challenges, and quizzes to reinforce what you’ve learned, all accessible on any device at any time. By completing our courses, you not only enhance your knowledge but you’re also building an impressive portfolio that showcases your skills. Continue your educational journey with us at Zenva, where you can go from beginner to professional while learning at your own pace.

Conclusion

Through the power of VisualShaderNodeParameters in Godot, you’ve seen how seemingly complex visual effects can be intuitively created and controlled. These building blocks pave the way for truly dynamic and interactive gaming experiences. Remember, this is just a glimpse of what can be achieved with Godot’s robust shader system and visual scripting tools. We encourage you to keep experimenting, exploring, and enhancing your game worlds with creative visual effects.

As we wrap up this tutorial, consider how each new skill learned with Zenva can open doors to endless possibilities in game development. Whether you choose to continue your education with our Godot Game Development Mini-Degree or by diving into our specialized Godot courses, you are taking steps toward transforming your imaginative concepts into playable realities. Keep challenging yourself, and let Zenva be your guide on this exciting path to becoming a game creation wizard.

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