GPUParticlesCollisionHeightField3D in Godot – Complete Guide

Welcome to the fascinating world of particle physics in game development! Today, we’re diving into the realm of real-time particle collisions using Godot 4, focusing on the “GPUParticlesCollisionHeightField3D” class. This powerful feature allows you to create compelling particle effects that interact with the game’s environment in an efficient and dynamic way. Whether you’re developing a serene setting with particles gently colliding with the terrain or crafting an explosive scene where every particle impact counts, this tutorial will equip you with the knowledge to make your virtual world come alive. So, let’s embark on this journey together and learn how to harness the potential of particle collisions to elevate the quality of your game development projects.

What is GPUParticlesCollisionHeightField3D?

GPUParticlesCollisionHeightField3D is a class within Godot 4’s powerful game development engine. It functions as a real-time, heightmap-shaped 3D particle attractor, specifically influencing GPUParticles3D nodes. This means that you can simulate particles that collide with a surface that resembles the ups and downs of a terrain, such as hills and valleys, without intricate geometries and with the benefit of real-time updates.

What is it for?

This class is perfect for scenarios where you need to represent terrain-based interactions, especially for outdoor particle effects like rain, snow, or dust that respond to the landscape. It provides an efficient way to incorporate collision effects without the need for complex and performance-heavy collision computations.

Why should I learn it?

Learning how to use GPUParticlesCollisionHeightField3D unlocks a new level of interactivity in your games. It empowers you to:

– Create more authentic and immersive environments with particles that realistically interact with the terrain.
– Optimize your game’s performance by utilizing a more efficient collision detection method compared to other complex systems.
– Add dynamic and responsive weather effects or other particle-based phenomena that can adapt to the game’s geometry in real-time.

Understanding this class will significantly enhance the visual fidelity of your games, making them much more engaging and enjoyable for your players. Now, let’s roll up our sleeves and dive into the coding tutorial to see GPUParticlesCollisionHeightField3D in action.

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Setting up a Basic Scene with GPUParticlesCollisionHeightField3D

Before we jump into the intricacies of GPUParticlesCollisionHeightField3D, let’s set up a basic 3D scene in Godot which we will use to demonstrate particle collisions. We’ll start by creating a simple terrain and a GPUParticles3D node.

var terrain =
terrain.mesh = preload("res://terrain.tres")
terrain.translation.y = -1

var particles =

In this code, we’re preloading a terrain mesh and adding it to the scene. We’ve positioned the terrain slightly below the origin and then created a GPUParticles3D instance and added it to the scene as well.

Initializing the Particle Collision Height Field

Next, we’ll initialize our GPUParticlesCollisionHeightField3D and set it up so that our particles will interact with the terrain object.

var collision_heightfield =
collision_heightfield.transform.origin.y = -0.5 
collision_heightfield.height_range_min = -1
collision_heightfield.height_range_max = 1

particles.process_material =
particles.process_material.shader = preload("res://particle_shader.shader")
particles.collision = collision_heightfield

Here, we’ve created a new GPUParticlesCollisionHeightField3D instance, moved it up by half a unit to align it correctly with our terrain, and set the minimum and maximum height range for collisions. We then assign it as the collision object for our particle system.

Creating a Custom Particle Shader

To make our particles interact with the collision heightfield visually, we’ll need to create a custom shader for the particles. Here’s a basic shader setup:

shader_type particles;

void particle() {
  // Basic particle color and size
  COLOR = vec4(1.0, 1.0, 1.0, 1.0);
  SIZE = 0.1;

This shader sets the color and size of the particles. For the sake of this example, all particles are white and have a uniform size of 0.1.

Configuring the Particle System’s Parameters

With the custom shader in place, we need to configure our particle system’s parameters to see the effect of the collision field.

particles.emitting = true
particles.amount = 1000
particles.lifetime = 5.0
particles.emission_shape = GPUParticles3D.EMISSION_SHAPE_BOX
particles.emission_box_extents = Vector3(5, 0, 5)
particles.direction = Vector3(0, -1, 0)
particles.initial_velocity = 10.0
particles.fixed_fps = 60

These settings enable our particle system to emit 1000 particles over a 5-second lifetime. We define an emission shape of a box with certain extents, set the particles to move downwards, and give them an initial velocity.

Adjusting Particle Collision Response

To demonstrate collision, we adjust how the particles respond upon hitting the terrain.

particles.collision_bounce = 0.3
particles.collision_friction = 0.1
particles.collision_responsiveness = 0.9

These parameters control the bounce, friction, and responsiveness of particles when they collide with the height field. Tweak them to see how different values affect the behavior of the particles upon impact.

With these basics covered, you now have a working example of real-time particle collisions within a Godot scene using GPUParticlesCollisionHeightField3D. Experiment with different configurations and see how it affects your particles! In the next part of our tutorial, we’ll delve deeper into more advanced configurations and options available with GPUParticlesCollisionHeightField3D. Stay tuned!Integrating particle collisions with your terrain requires a harmonious relationship between the particle system and the collision object. Let’s continue refining our particle collision system and see how different parameters can further tailor our particles’ behavior upon interacting with the terrain.

Advanced Configuration of GPUParticlesCollisionHeightField3D

To truly leverage the power of the GPUParticlesCollisionHeightField3D class, it’s important to understand the more sophisticated settings at your disposal. Below are code snippets illustrating various configurations that you can experiment with.

First, consider varying the damping factor, which controls how the energy of particles is dissipated upon collision:

particles.collision_damping = 0.5

A higher damping factor means that particles lose more energy upon impact, mimicking a softer collision, such as hitting a pile of leaves.

Another parameter, the stickiness, dictates the tendency of particles to cling to the collision surface:

particles.collision_stickiness = 0.1

With this, particles appear to stick to the collision heightfield briefly, useful for simulating wet surfaces or more viscous environments.

Understanding that real-world collisions often involve randomness, you can introduce a level of variation:

particles.collision_randomness = 0.2

This emulates the naturally occurring irregularity in collisions, making the particle simulation more organic and less uniform.

Now, diving deeper into the ‘GPUParticlesCollisionHeightField3D’, we have massive control over how we render our collisions:

collision_heightfield.resolution = 256
collision_heightfield.scale = Vector3(2, 1, 2)
collision_heightfield.update_mode = GPUParticlesCollisionHeightField3D.UPDATE_MODE_ALWAYS

– The `resolution` defines the granularity of the height field; a higher value leads to finer collision detection but at the cost of performance.
– The `scale` can be adjusted to fit the size of the height field to your terrain.
– The `update_mode` controls how frequently the height field updates, with `UPDATE_MODE_ALWAYS` ensuring that any changes in the terrain reflect in real-time in the collisions.

Lastly, if you are dealing with constantly changing terrain, you can update the collision heightfield in code to match the updated terrain. This ensures that your particles will always interact correctly with the new terrain shape:

// Call this function whenever the terrain changes shape
func update_collision_heightfield():
    collision_heightfield.heightmap_image = updated_heightmap_image
    collision_heightfield.resolution = updated_heightmap_image.get_width()

Here, we’re updating the heightmap image of the collision heightfield and then forcing an update of the collider, to match the new terrain layout.

Utilizing these advanced settings, Godot developers can fine-tune their particle systems to react to the virtual world in a more convincing and engaging way. Feel free to experiment with the different configurations and parameters to create unique and mesmerizing particle effects that bring your game environment to life.

Remember, at Zenva, we strive for comprehensive education that not only teaches you the tools but also how to think creatively within the framework of a game engine. So go ahead, tinker with the settings, and let your creativity guide the development process!As your skills in particle collision develop, you’ll want to expand and refine your repertoire with more code examples. Let’s explore further functionalities and options to give you the ability to create even more sophisticated particle interactions.

Adjusting the height field normal data is crucial for realistic particle behavior, especially when your particles need to slide off slopes or differentiate between varying angles of the terrain.

// Configure height field normal parameters
collision_heightfield.normal_texture = preload("res://normal_texture.png")
collision_heightfield.normal_enabled = true
collision_heightfield.normal_strength = 0.8

The `normal_texture` is a vital component that imparts particles awareness of the surface’s orientation, `normal_enabled` toggles this feature, and `normal_strength` determines the influence of the normal map on collision behaviors, such as sliding or bouncing off slopes.

Let’s not forget about the visual aspect; you can also adjust the particle draw order, which changes how particles are rendered based on their depth relative to the camera:

// Change the draw order for visual effects
particles.draw_order = GPUParticles3D.DRAW_ORDER_VIEW_DEPTH

The ‘DRAW_ORDER_VIEW_DEPTH’ ensures that particles closer to the camera are rendered on top, creating a sense of depth.

To enhance efficiency, consider employing the visibility rect hint, which optimizes drawing operations by only rendering particles within a specified AABB (Axis Aligned Bounding Box):

// Define a Visibility Rect to optimize rendering
particles.visibility_rect = AABB(Vector3(-10, -1, -10), Vector3(20, 2, 20))

This visibility optimization is particularly useful for expansive terrains, where you want to limit computational overhead.

For dynamic scenes, you can change the parameters of the particle system in real-time based on gameplay events or environmental conditions:

// Dynamically adjust particle system during runtime
func adjust_particle_parameters(density: float, wind_vector: Vector3):
    particles.amount = 500 * density
    particles.direction = wind_vector

Here we’re changing both the number of particles and their direction, which can mimic effects such as increasing rain density or changing wind direction.

Wind Influence on Particle System in Godot
Image showing the influence of wind on the particle system within Godot 4.

With GPUParticlesCollisionHeightField3D, it’s also possible to interactively modify the collision’s height data. If you’re working with deformable or dynamic terrains, you’ll want to regularly update these collisions:

// Update the collision heightmap in real-time
func update_terrain_heightmap(heightmap_image: Image):
    collision_heightfield.heightmap_image = heightmap_image

This snippet demonstrates how to change the heightmap image used for collisions, ensuring that your particles accurately respond to the shifting shape of the terrain.

Additionally, we can define a custom emission shape to control where particles emerge within our scene:

// Customizing emission shape for particle system
var custom_emission_shape : ArrayMesh = preload("res://custom_shape.mesh")
particles.emission_shape_custom = custom_emission_shape
particles.emission_shape = GPUParticles3D.EMISSION_SHAPE_CUSTOM

The `emission_shape_custom` property allows us to assign a preloaded mesh as the new shape from which particles will be emitted.

By mastering these additional features and parameters, your game’s environments will evolve into dynamic, reactive entities. This not only enhances the player’s experience but also demonstrates a high degree of technical acumen and creative problem-solving. And remember, at Zenva, we are always here to guide you on your learning journey with in-depth courses and tutorials that make game development accessible and fun. So go on, apply these new skills in your projects and watch your game worlds bloom with life and interactivity!

Continuing Your Godot Development Journey

Now that you’ve taken your first steps with GPUParticlesCollisionHeightField3D in Godot 4 and understand how particle physics can elevate a gaming experience, you’re probably eager to keep building your game development skills. We at Zenva know the thrill that comes with learning and the satisfaction of applying new knowledge to create something amazing!

To further your education and take your Godot skills to the next level, consider exploring our Godot Game Development Mini-Degree. This comprehensive learning path will guide you through a variety of topics, from the basics of 2D and 3D game creation to more complex systems like RPG mechanics and UI development. With a project-based approach and on-demand course access, you can learn at your own pace and build a professional portfolio along the way.

And if you’re interested in broadening your Godot expertise, we offer a diverse collection of Godot courses tailored for both beginners and seasoned developers. Each carefully crafted course aims to provide you with the in-demand skills needed to excel in your game development endeavors.

The journey of learning never truly ends, and we’re here to support you every step of the way. Dive into our courses, and let’s create incredible game experiences together!


As you’ve seen, mastering particle collisions with Godot 4’s GPUParticlesCollisionHeightField3D not only brings new levels of interactivity and realism to your games but also showcases your ability to manipulate the engine’s cutting-edge features. By continuing to learn and expand on your existing foundation, you lay down the bricks for a fulfilling and successful game development career.

We at Zenva encourage you to keep the momentum going by immersing yourself in our Godot Game Development Mini-Degree, where every tutorial, every course, and every bit of knowledge we offer serves as a step towards achieving your dream of making captivating games. Join us, and let’s turn your passion for game development into tangible, awe-inspiring projects that delight players around the world. Let the adventure continue!

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