Javascript

Harnessing the Power of Threlte - Building Reactive Three.js Scenes in Svelte

Published Aug 14, 2023

Updated Aug 15, 2023

6 min read

This article was written over 18 months ago and may contain information that is out of date. Some content may be relevant but please refer to the relevant official documentation or available resources for the latest information.

Introduction

Web development has evolved to include immersive 3D experiences through libraries like Three.js. This powerful JavaScript library enables the creation of captivating 3D scenes within browsers.

Three.js: The 3D Powerhouse

Three.js democratizes 3D rendering, allowing developers of all skill levels to craft interactive 3D worlds.

Svelte Ecosystem: Svelte Cubed and Svelthree

The Svelte ecosystem presents solutions like Svelte Cubed and Svelthree, which bridges Svelte with Three.js, offering streamlined reactivity for 3D web experiences.

Introducing Threlte v6: Uniting SvelteKit 1.0, Svelte 4, and TypeScript

Threlte v6 is a rendering and component library for Svelte that seamlessly integrates Three.js. By harnessing TypeScript's types, it provides a robust and delightful coding experience.

In this tutorial, we'll showcase Threlte's capabilities by building an engaging website header: an auto-rotating sphere that changes color on mouse down. Using Threlte v6, SvelteKit 1.0, and Three.js, we're set to create a visually stunning experience. Let's dive in!

Setting up Threlte

Before building our scene, we need to set up Threlte. We can scaffold a new project using the CLI or manually install Threlte in an existing project.

Option 1: Scaffold a New Threlte Project

Create a new SvelteKit project and install Threlte with:

npm create threlte my-project

Option 2: Manual Installation

For an existing project, select the necessary Threlte packages and install:

npm install three @threlte/core @threlte/extras @threlte/rapier @dimforge/rapier3d-compat @threlte/theatre @theatre/core @theatre/studio @types/three

Configuration adjustments for SvelteKit can be made in the "vite.config.js" file:

const config = {
  // ...
  ssr: {
    noExternal: ['three']
  }
};

With Threlte configured, we're ready to build our interactive sphere. In the next chapter, we'll lay the groundwork for our exciting 3D web experience!

Exploring the Boilerplate of Threlte

Upon scaffolding a new project using npm create threlte, a few essential boilerplate files are generated. In this chapter, we'll examine the code snippets from three of these files: lib/components/scene.svelte, routes/+page.svelte, and lib/components/app.svelte.

lib/components/scene.svelte: This file lays the foundation for our 3D scene. Here's a brief breakdown of its main elements:
- Perspective Camera: Sets up the camera view with a specific field of view and position, and integrates OrbitControls for auto-rotation and zoom management.
- Directional and Ambient Lights: Defines the lighting conditions to illuminate the scene.
- Grid: A grid structure to represent the ground.
- ContactShadows: Adds shadow effects to enhance realism.
- Float: Wraps around 3D mesh objects and defines floating properties, including intensity and range. Various geometrical shapes like BoxGeometry, TorusKnotGeometry, and IcosahedronGeometry are included here.
routes/+page.svelte: This file handles the ui of the index page and imports all necessary components we need to bring our vibrant design to life.
lib/components/app.svelte: This file is where you would typically define the main application layout, including styling and embedding other components.

Heading to the Fun Stuff

With the boilerplate components explained, we're now ready to dive into the exciting part of building our interactive 3D web experience. In the next section, we'll begin crafting our auto-rotating sphere, and explore how Threlte's robust features will help us bring it to life.

Creating a Rotating Sphere Scene

In this chapter, we'll walk you through creating an interactive 3D sphere scene using Threlte. We'll cover setting up the scene, the sphere, the camera and lights, and finally the interactivity that includes a scaling effect and color changes.

1. Setting Up the Scene

First, we need to import the required components and utilities from Threlte.

import { T } from '@threlte/core';
import { OrbitControls } from '@threlte/extras';

2. Setting Up the Sphere

We'll create the 3D sphere using Threlte's <T.Mesh> and <T.SphereGeometry> components.

<T.Mesh>
	<T.SphereGeometry args={[1, 32, 32]} />
	<T.MeshStandardMaterial color={`rgb(${sphereColor})`} roughness={0.2} />
</T.Mesh>

<T.Mesh>: This is a component from Threlte that represents a 3D object, which in this case is a sphere. It's the container that holds the geometry and material of the sphere.
<T.SphereGeometry args={[1, 32, 32]} />: This is the geometry of the sphere. It defines the shape and characteristics of the sphere. The args attribute specifies the parameters for the sphere's creation:
- The first argument (1) is the radius of the sphere.
- The second argument (32) represents the number of width segments.
- The third argument (32) represents the number of height segments.
<T.MeshStandardMaterial color={rgb(${sphereColor})} roughness={0.2} />: This is the material applied to the sphere. It determines how the surface of the sphere interacts with light. The color attribute specifies the color of the material. In this case, the color is dynamic and defined by the sphereColor variable, which updates based on user interaction. The roughness attribute controls the surface roughness of the sphere, affecting how it reflects light.

3. Setting Up the Camera and Lights

Next, we'll position the camera and add lights to create a visually appealing scene.

<T.PerspectiveCamera makeDefault position={[-10, 20, 10]} fov={15}>
	<OrbitControls
		enableZoom={false}
		enablePan={false}
		enableDamping
		autoRotate
		autoRotateSpeed={1.5}
	/>
</T.PerspectiveCamera>
<T.DirectionalLight intensity={0.8} position.x={10} position.y={10} />
<T.AmbientLight intensity={0.02} />

<T.PerspectiveCamera>: This component represents the camera in the scene. It provides the viewpoint through which the user sees the 3D objects. The position attribute defines the camera's position in 3D space. In this case, the camera is positioned at (-10, 20, 10). The fov attribute specifies the field of view, which affects how wide the camera's view is.
- makeDefault: This attribute makes this camera the default camera for rendering the scene.
<OrbitControls>: This component provides controls for easy navigation and interaction with the scene. It allows the user to pan, zoom, and orbit around the objects in the scene. The attributes within the <OrbitControls> component configure its behavior:
- enableZoom: Disables zooming using the mouse scroll wheel.
- enablePan: Disables panning the scene.
- enableDamping: Enables a damping effect that smoothens the camera's movement.
- autoRotate: Enables automatic rotation of the camera around the scene.
- autoRotateSpeed: Defines the speed of the auto-rotation.
<T.DirectionalLight>: This component represents a directional light source in the scene. It simulates light coming from a specific direction. The attributes within the <T.DirectionalLight> component configure the light's behavior:
- intensity: Specifies the intensity of the light.
- position.x and position.y: Define the position of the light source in the scene.
<T.AmbientLight>: This component represents an ambient light source in the scene. It provides even lighting across all objects in the scene. The intensity attribute controls the strength of the ambient light.

4. Interactivity: Scaling and Color Changes

Now we'll add interactivity to the sphere, allowing it to scale and change color in response to user input.

First, we'll import the required utilities for animation and set up a spring object to manage the scale.

import { spring } from 'svelte/motion';
import { onMount } from 'svelte';
import { interactivity } from '@threlte/extras';

interactivity();

const scale = spring(0, { stiffness: 0.1 });

onMount(() => {
	scale.set(1);
});

We'll update the sphere definition to include scaling:

<T.Mesh scale={$scale} on:pointerenter={() => scale.set(1.1)} on:pointerleave={() => scale.set(1)}>
	<T.SphereGeometry args={[1, 32, 32]} />
	<T.MeshStandardMaterial color={`rgb(${sphereColor})`} roughness={0.2} />
</T.Mesh>

Lastly, we'll add code to update the color of the sphere based on the mouse's position within the window.

let mousedown = false;
let rgb: number[] = [];

function updateSphereColor(e: MouseEvent) {
	if (mousedown) {
		rgb = [
			Math.floor((e.pageX / window.innerWidth) * 255),
			Math.floor((e.pageY / window.innerHeight) * 255),
			150
		];
	}
}
window.addEventListener('mousedown', () => (mousedown = true));
window.addEventListener('mouseup', () => (mousedown = false));
window.addEventListener('mousemove', updateSphereColor);

$: sphereColor = rgb.join(',');

We have successfully created a rotating sphere scene with scaling and color-changing interactivity. By leveraging Threlte's capabilities, we have built a visually engaging 3D experience that responds to user input, providing a dynamic and immersive interface.

Adding Navigation and Scroll Prompt in `app.svelte`

In this chapter, we'll add a navigation bar and a scroll prompt to our scene. The navigation bar provides links for user navigation, while the scroll prompt encourages the user to interact with the content. Here's a step-by-step breakdown of the code:

1. Importing the Canvas and Scene

The Canvas component from Threlte serves as the container for our 3D scene. We import our custom Scene component to render within the canvas.

import { Canvas } from '@threlte/core';
import Scene from './Scene.svelte';

2. Embedding the 3D Scene

The Canvas component wraps the Scene component to render the 3D content. It is positioned absolutely to cover the full viewport, and the z-index property ensures that it's layered behind the navigation elements.

<div class="sphere-canvas">
	<Canvas>
		<Scene />
	</Canvas>
</div>

We use a <nav> element to create a horizontal navigation bar at the top of the page. It contains a home link and two navigation list items. The styling properties ensure that the navigation bar is visually appealing and positioned correctly.

<nav>
	<a href="/">Home</a>
	<ul>
		<li>Explore</li>
		<li>Learn</li>
	</ul>
</nav>

4. Adding the Scroll Prompt

We include a "Give a scroll" prompt with an <h1> element to encourage user interaction. It's positioned near the bottom of the viewport and styled for readability against the background.

<h1>Give a scroll</h1>

5. Styling the Components

Finally, the provided CSS styles control the positioning and appearance of the canvas, navigation bar, and scroll prompt. The CSS classes apply appropriate color, font, and layout properties to create a cohesive and attractive design.

.sphere-canvas {
	width: 100%;
	height: 100%;
	position: absolute;
	top: 0;
	left: 0;
	z-index: 1;
}

nav {
	display: flex;
	color: white;
	z-index: 2;
	position: relative;
	padding: 4rem 8rem;
	justify-content: space-between;
	align-items: center;
}

nav a {
	text-decoration: none;
	color: white;
	font-weight: bold;
}

nav ul {
	display: flex;
	list-style: none;
	gap: 4rem;
}

h1 {
	color: white;
	z-index: 2;
	position: absolute;
	font-size: 3rem;
	left: 50%;
	top: 75%;
	transform: translate(-50%, -75%);
}

Head to the github repo to view the full code.

Check out the result: https://threlte6-spinning-ball.vercel.app/

Conclusion

We've successfully added navigation and a scroll prompt to our Threlte project in the app.svelte file. By layering 2D HTML content with a 3D scene, we've created an interactive user interface that combines traditional web design elements with immersive 3D visuals.

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About the author(s)

Ian Sam Mungai
@iansamz @iansamz

Svelte 5 is Here!

Svelte 5 was finally released after a long time in development. Fortunately, we've been able to test it for some time, and now it has a stable release. Let's dig into its features and why this is such a significant change, even though Svelte 4 code is almost 100% compatible. Svelte syntax everywhere This is one of my favorite additions. Previously, Svelte syntax was limited to a component element. Refactoring code from a component and moving it to a JavaScript file worked differently. Now you can use the .svelte.js or .svelte.ts extension, which allows you to use the same syntax everywhere. It's important to note that it's a way to express that this is not just JS, and what you write may be compiled to something else, just like .svelte files are not just html even though they look very similar. Runes The introduction of runes is one of the most significant changes in Svelte. Many users felt attracted to variables being instantly reactive in previous versions. ` There was, however, a lot of magic underneath and a considerable amount of work from the compiler to make it behave reactively. $state In Svelte 5, a reactive variable has to be explicitly declared using the $state rune, which brings a clear distinction between what is reactive and what isn’t. ` In the previous code, $state is not an actual function being called; it's a hint for the compiler to do something special with this declaration. Rune names always start with a dollar sign ($) and do not need to be imported. However, there’s much more to the changes than just the way we declare reactive variables. Runes bring a lot of new features that make Svelte 5 a great improvement. In Svelte 5, objects or arrays use Proxies to allow for granular reactivity, meaning that individual properties in an object are reactive, even if they are nested objects or arrays. If you modify a property, it will only update that property and will not trigger an update on the whole object. It also supports triggering updates when methods like array.push are called. In previous versions, an assignment was required to trigger an update: ` To have a similar behavior of svelte 4 (no deep reactivity), use the $state.raw() rune. This syntax of .* is common for related features of a rune: $state.raw() will require an assignment to trigger reactivity. ` Because proxies are used, you may need to extract the underlying state instead of the proxy itself. In that case, $state.snapshot() should be used: ` $derived We will use $derived and $derived.by to declare a derived state. The two runes are essentially the same, except one allows us to use a function instead of an expression, allowing for more complex operations to calculate the derived values. ` $effect Effects are useful for running something triggered by a change in state. One of the things you'll note from the $effect rune is that dependencies don't need to be explicit. Those will be picked from reactive values read synchronously in the body of the effect function. ` Something to bear in mind is that these dependencies are picked each time the effect runs. The values read during the last run become the dependencies of the effect. ` Depending on the result of the random method, foo or bar will stop being a dependency of the effect. You should place them outside the condition so they can trigger reruns of the effect. *Variants* of the effect rune are $effect.pre, which runs before a DOM update, and $effect.tracking(), which checks for the context of the effect (true for an effect inside an effect or in the template). $props This rune replaces the export let keywords used in previous versions to define a component's props. To use the $props syntax, we can consider it to return an object with all the properties a component receives. We can use JavaScript syntax to destructure it or use the rest property if we want to retrieve every property not explicitly destructured.. ` $bindable If you want to mutate a prop so that the change flows back to the parent, you can use the $bindable prop to make it work in both directions. A parent component can pass a value to a child component, and the child component is able to modify it, returning the data back to the parent component. ` $inspect The $inspect rune only works in dev mode and will track dependencies deeply. By default, it will call console.log with the provided argument whenever it detects a change. To change the underlying function, use $inspect.with().with): ` $host The host rune gives access to the host element when compiling as a custom element: ` ` Other changes Another important change is that component events are just props in Svelte 5, so you can destructure them using the $props() rune: ` A special children property can be used to project content into a component instead of using slots. Inside the components, use the [@render[(https://svelte.dev/docs/svelte/@render) tag to place them. ` Optional chaining (?.) prevents from attempting to render it if no children are passed in. If you need to render different components in different places (named slots before Svelte 5, you can pass them as any other prop, and use @render with them. Snippets Snippets allow us to declare markup slices and render them conveniently using the render tag (@render). They can take any number of arguments. ` Snippets can also be passed as props to other components. ` ` Conclusion Some exciting changes to the Svelte syntax were introduced while, at the same time, maximum compatibility efforts were made. This was a massive rewrite with numerous improvements in terms of performance, bundle size, and DX. Besides that, a new CLI has been released, making the whole experience of starting a project or adding features delightful. If you haven't tried Svelte before, it's a great time to try it now....

Nov 27, 2024

4 mins

Svelte

Svelte 4 Launch Party Recap

In this Svelte 4 Launch Party event, our panelists discussed the release of Svelte 4. In this wrap-up, we will talk about panel discussions with Svelte core team members, which is an in-depth exploration of the Svelte 4 release, highlighting its key features and performance enhancements. You can watch the full Svelte 4 Launch Party event on the This Dot Media's YouTube channel. Here is a complete list of the host and panelists that participated in this online event: Hosts: - Tracy Lee, CEO, This Dot, @ladyleet - Rob Ocel, Team Lead & Software Architect, This Dot, @robocell Panelists: - Geoff Rich, Svelte Core Team, @geoffrich_ - Simon Holthausen, Full-time Svelte maintainer, @dummdidumm_ - Puru Vijay, Svelte Core Team, @puruvjdev - Benn McCann, SvelteKit Maintainer, @BenjaminMcCann Introductions Geoff, one of the Svelte maintainers, started the introductions. He expressed his excitement about the new major version of Svelte and shared his years of experience using the framework. In his day job, Geoff is a Senior Software Engineer at Ordergroove. Simon, a full-time Svelte maintainer working at Vercel, was busy preparing and finally releasing Svelte 4. He happily noted that there were very few bugs, and everything seemed to be working smoothly. Simon's dedication to maintaining the framework has contributed significantly to its success. Puru, a college student, showcased his impressive skills by working on the website and the REPL for Svelte. Balancing his studies with web development, Puru demonstrated his passion for Svelte and his contributions to its ecosystem. Ben primarily focuses on Svelte Kit, but also pitched in with Svelte 4. Besides his work on Svelte, Ben is an entrepreneur, adding an extra dimension to his diverse skill set. His contributions to the Svelte community have been invaluable. What Should Everyone Be Excited About in Svelte 4? Svelte 4 has arrived, and while it may not be packed with mind-blowing features, there are several neat little improvements that are worth getting excited about. The main focus of this release was on maintenance and cleaning up the framework to pave the way for the big Svelte 5 release. So don't worry, there are bigger things in the pipeline! One of the first things to note is that file sizes in Svelte 4 have significantly decreased by about 10 to 12 fold. This means that your website will load much faster, thanks to the reduced bundle size. Additionally, improvements have been made in hydration, which affects the speed at which pages hydrate. The core around hydration has become smaller, resulting in improved performance. Another noteworthy enhancement in Svelte 4 is the complete overhaul of custom element support. This change, although technically a breaking one, introduces a new wrapper approach. Previously, in Svelte 3, you had to use every Svelte component as a custom element, even if you wanted to keep certain components as internal implementation details. With the wrapper approach, you now have the flexibility to use components as regular Svelte components internally, fixing a range of bugs and fulfilling numerous feature requests. This change proved to be a tremendous success, resolving multiple issues in one fell swoop. Svelte 4 brings value to your day-to-day development experience. For example, the improved type generation and autocomplete have made working with Svelte components a lot smoother. The autocomplete feature now grabs the correct import, eliminating the frustrations of navigating to the wrong files. Additionally, the introduction of declaration maps allows you to see the actual source code, providing a better understanding of the inner workings of Svelte. There's also good news for those who want to contribute to the Svelte codebase. In Svelte 4, the entire codebase has been converted from TypeScript to JavaScript with JS Docs. While type checking is still in place to ensure error-free development, this change simplifies the process of working with the source code. Developers can now directly edit the source and test changes without worrying about the mapping between TypeScript and JavaScript. In terms of performance, the reduction in bundle sizes has made a significant impact. Although the size reduction percentage may have been misunderstood by some, primarily referring to the compiler size rather than the runtime bundle, it has tangible benefits in scenarios like online tutorials and interactive experiences. Beyond the technical improvements, Svelte 4 also brings updates to the documentation site and the main website. The team has put in considerable effort to enhance the user experience, making it easier to navigate and find the information you need. Puru Does a Run Through of the Updates to the Svelte.dev Site Puru shares exciting news to share about the overhaul of the svelte.dev website. First things first, let's talk about the star of the show: dark mode. It's finally here, and it's a game-changer. They’ve given the entire site a fresh redesign, taking inspiration from the sleek look of kit.svelte.dev. You'll notice some similarities, but they’ve added their own unique touch to make it shine. They’re now linking to the improved tutorial on learn.svelte.dev, which is definitely worth checking out. Now, let's dive into the docs. They've made some significant changes to make your browsing experience a breeze. Instead of a single page, they've divided everything into multiple pages, making it super easy to find what you're looking for. Each component, logic block, and style module has its own dedicated page. It's all organized and up-to-date, thanks to the auto-generation from the source code. Say goodbye to outdated information and hello to hassle-free browsing. They've introduced some fantastic new features that you're going to love. In the REPL, they've added multiple cursors, making coding even more efficient. Plus, they've created a REPL User Guide, packed with handy shortcuts and nifty tips and tricks. And here's the best part: our code snippets now support TypeScript. Just a simple click, and you'll have the TypeScript equivalent at your fingertips. It couldn't get any easier to level up your coding game! So, head over to the new website, immerse yourself in the revamped docs, and enjoy all the fantastic updates we've made. And don't forget to check out the blog section for more in-depth information. Happy browsing, and get ready to experience the best of the new and improved website! Upgrading from Svelte 3 to Svelte 4 Well there are a few things you need to know. But don't worry, it's not too complicated. First off, you'll find all the breaking changes highlighted and summarized on the migration Doc Page. So, if something breaks, you can check it out there. If you're still on Svelte 3, the best way to start is by using the migration script. Just type in npx svelte-migrate svelte-4 in your command line, and it will go through your code base and automatically update things like tightened up types and local transitions. The migration script will even ask you if you want to migrate your global transitions or not. It's like a little questionnaire to make sure everything goes smoothly. The migration script does a lot of the heavy lifting for you, updating dependencies in your package.json and ensuring peer dependency versions match up. It takes care of most things, but there might be a few other changes you'll need to handle. That's where the migration guide comes in handy. It covers all the other changes and helps you navigate through them. Now keep in mind that upgrading to Svelte 4 might require at least Node 16. So, if you're using older dependencies that are holding you back from upgrading Node, it's time to poke your manager or tech lead and emphasize the need to stay current. After all, using outdated versions can pose security vulnerabilities. So make a strong case for the upgrade and let them know it's time to invest in keeping things up to date. Geoff talked about how he has already upgraded a few sites to Svelte 4, and honestly, just upgraded the dependencies, and it worked like a charm. He didn't even bother running the migration script himself. Different projects may have different needs, so it's always good to be aware of any potential obstacles. Stay up to date and remember, keeping things secure is a top priority! Svelte 4 and How It Works with Svelte Kit If you're using Svelte Kit and thinking about upgrading to Svelte 4, here's what you need to know. The good news is that you can stick with your current version of Svelte Kit if you want, but there will be a warning about the peer dependencies not matching up. We made a small change to officially support Svelte 4 within Svelte Kit. But other than that, not much else has changed. One important thing to remember is to upgrade the plugins file that Svelte Kit uses. You can do this by updating your lock file or simply upgrading to the latest Svelte Kit, which will take care of it for you. The migration script handles all the necessary updates, so running it will ensure everything works smoothly. When it comes to impact, Svelte 4 brings some improvements. Your hydration code will be smaller, and the hydration speed will be faster, which means your final app bundle could be around 10% smaller. We've been working on even more performance enhancements, and using the Chrome performance tab in the developer tools can help you identify areas that need improvement. So, in a nutshell, upgrading to Svelte 4 is optional for Svelte Kit users. But, it brings benefits like smaller code and faster hydration. Just remember to update the plugins file and use the migration script to handle any necessary changes. Keep an eye on the Chrome performance tab for optimization opportunities. Are Svelte and Svelte Kit Going to be Paired in the Future in Updates or Stay Independent? When it comes to updates for Svelte and Svelte Kit, there's a relationship between the two, but they also have their own focuses. The development of Svelte and Svelte Kit is somewhat interconnected, with learnings and improvements transferring between them. While the maintainers tend to focus on one major project at a time to gather feedback and make meaningful changes, they do draw lessons from both and apply them accordingly. For example, the decision to make transitions local by default in Svelte 4 stemmed from insights gained during the development of Svelte Kit. Although there may be periods of emphasis on either Svelte or Svelte Kit, they are designed to complement each other and take advantage of each other's features. The development teams work on both code bases, ensuring a coordinated approach. While there may be a Svelte Kit 2 in the future, it's important to note that the release of Svelte 5 doesn't automatically mean a corresponding major update for Svelte Kit. The decision to introduce a new version depends on various factors, such as API changes and compatibility with the latest versions of Svelte, Node.js, and bundlers. Ultimately, the goal is to provide a seamless and optimized experience for developers using Svelte and Svelte Kit. By developing them in tandem and leveraging the benefits of each, the teams behind these projects ensure continuous improvements and adaptability to the evolving needs of the community. Svelte Dev Tools Repo and Funding for Svelte So, regarding the Svelte Dev Tools repo, it used to be a community-maintained project led by a contributor named Red Hatter. She developed and published it independently. But more recently, she transferred the repository to the Svelte team so that they could also contribute and provide support. Currently, the team hasn't been able to publish new versions of the extension to the store, so there might still be the Svelte 3 version available. However, they are working on publishing a new version and may ask users to switch over to it for Svelte 4. Now, let's talk about funding for Svelte. While financial support is definitely appreciated, the team also values something equally important—time. Companies can make a significant impact by allowing their employees to work on Svelte or Svelte Kit, fixing bugs, and contributing their time and expertise to improving the projects. Donations are welcome, of course, but finding skilled developers like Pooria (one of the Svelte team members) can be challenging even with funding available. So, giving employees the time and freedom to work on Svelte-related projects is highly appreciated and can have a significant positive impact. It's not just about money; it's about investing resources, whether financial or human, into the growth and development of the Svelte community. Getting Involved in Open Source If you're interested in getting involved in open source for Svelte, the journey can take different paths. One way to start is by creating projects or contributing to existing ones in the Svelte ecosystem. For example, Peru mentioned that he initially created a Svelte version of a tool called MacOS, which gained attention and led to him becoming a Svelte ambassador. Being active in the community, showcasing your work, and advocating for Svelte through speaking engagements or participating in events like Svelte Summit can also help raise your profile. Becoming a Svelte ambassador or being recognized by the core team doesn't necessarily require direct contributions to the Svelte codebase. You can contribute in various ways, such as creating engaging content like videos or blog posts that benefit the community, maintaining popular Svelte libraries, assisting users on platforms like Discord or Stack Overflow, and participating in GitHub discussions. The core team and community value not only code contributions but also the positive impact and dedication you bring to the Svelte community. It's worth noting that the journey can be unique for each person. Even if you haven't contributed to the Svelte codebase directly, like the ambassadors Hunter Byte and Joy of Code, you can still make a significant impact and be recognized for your contributions. For instance, Pooria mentioned that his first contribution was focused on creating the Svelte website rather than working on the core Svelte codebase. So, anyone with a passion for Svelte and a willingness to contribute can become a Svelte ambassador and actively participate in the open-source community. Contributing to Open Source Contributing to open-source projects like Svelte may seem daunting, but you don't have to understand the entire codebase from the start. Start by looking for beginner-friendly issues labeled as "good first issue" or similar tags. These provide a starting point to dive into the codebase. Follow the code path, use failing tests as guidance, and utilize features like control-clicking to navigate to relevant implementations. Documentation and contribution guides are valuable resources for newcomers. Svelte Kit, for instance, has focused on making its codebase beginner-friendly. If you encounter difficulties, join the project's Discord channel and seek guidance from experienced contributors. Providing feedback on areas where more documentation is needed can help improve the contributor experience. You can also contribute to adjacent tools related to Svelte, such as Prettier or ESLint plugins, which are maintained by the core team. These projects are often smaller in size and provide a manageable entry point. Additionally, non-coding contributions like improving project workflows or setting up testing and CI processes are also valuable. Remember that contributions, regardless of their scale, have a positive impact on the project and the open-source community. Focus on understanding the specific area you want to work on, leverage available resources, engage with the community, and consider contributing to adjacent projects. With these steps, you can jump into contributing to open source and start making a difference. Closing Thoughts from Panelists Simon shared his enthusiasm for the future of Svelte, particularly the highly anticipated Svelte 5. The recent addition of Dominic to the team has already made a significant impact, and the brainstorming sessions have been rewarding. Exciting things are on the horizon for Svelte users. Geoff encouraged everyone to give Svelte 4 a try and welcomes feedback and issue reports as they continue to refine and improve the framework. He emphasized that they are still in the early stages after the release and appreciate the community's support in upgrading their apps and providing valuable insights. Peru gave a special shout-out to Paulo Ricca, who has been instrumental in resolving issues with the new REPL. With Paulo's assistance, the REPL is now as stable and impressive as before. Peru expresses his gratitude for the collaboration. Ben extended his appreciation to the ecosystem integrations, mentioning the Storybook team and Jesse Beech, who contributed to optimizing file sizes and ensuring Svelte's compatibility with other JavaScript projects. The Svelte team is open to supporting and collaborating with anyone seeking to integrate Svelte with other tools in the ecosystem. Overall, the panelists were thankful, excited about the future, and grateful for the community's contributions and collaborations. The energy and positive feedback drove their motivation, and they encouraged everyone to continue exploring and pushing the boundaries of what Svelte can achieve. Conclusion In this Svelte 4 Launch Party, the panelists express their gratitude to the vibrant Svelte community for their unwavering support and positive energy. The launch of Svelte 4 and the promising developments of Svelte 5 have generated excitement and anticipation among developers. The core team's commitment to continuous improvement, collaboration with ecosystem integrations, and dedication to addressing user feedback are evident. As Svelte evolves, the contributions of individuals, whether through code, documentation, or community engagement, are valued and celebrated. With the momentum and enthusiasm surrounding Svelte, the future looks bright for this innovative framework and its passionate community....

Jun 30, 2023

12 mins

Svelte

A Deep Dive into SvelteKit Routing with Our Starter.dev GitHub Showcase Example

Introduction SvelteKit is an excellent framework for building web applications of all sizes, with a beautiful development experience and flexible filesystem-based routing. At the heart of SvelteKit is a filesystem-based router. The routes of your app — i.e. the URL paths that users can access — are defined by the directories in your codebase. In this tutorial, we are going to discuss SvelteKit routing with an awesome SvelteKit GitHub showcase built by This Dot Labs. The showcase is built with the SvelteKit starter kit on starter.dev. We are going to tackle: - Filesystem-based router - +page.svelte - +page.server - +layout.svelte - +layout.server - +error.svelte - Advanced Routing - Rest Parameters - (group) layouts - Matching Below is the current routes folder. Prerequisites You will need a development environment running Node.js; this tutorial was tested on Node.js version 16.18.0, and npm version 8.19.2. Filesystem-based router The src/routes is the root route. You can change src/routes to a different directory by editing the project config. ` Each route directory contains one or more route files, which can be identified by their + prefix. +page.svelte A +page.svelte component defines a page of your app. By default, pages are rendered both on the server (SSR) for the initial request, and in the browser (CSR) for subsequent navigation. In the below example, we see how to render a simple login page component: ` +page.ts Often, a page will need to load some data before it can be rendered. For this, we add a +page.js (or +page.ts, if you're TypeScript-inclined) module that exports a load function. +page.server.ts If your load function can only run on the server— ie, if it needs to fetch data from a database or you need to access private environment variables like API key— then you can rename +page.js to +page.server.js, and change the PageLoad type to PageServerLoad. To pass top user repository data, and user’s gists to the client-rendered page, we do the following: ` The page.svelte gets access to the data by using the data variable which is of type PageServerData. ` +layout.svelte As there are elements that should be visible on every page, such as top-level navigation or a footer. Instead of repeating them in every +page.svelte, we can put them in layouts. The only requirement is that the component includes a for the page content. For example, let's add a nav bar: ` +layout.server.ts Just like +page.server.ts, your +layout.svelte component can get data from a load function in +layout.server.js, and change the type from PageServerLoad type to LayoutServerLoad. ` +error.svelte If an error occurs during load, SvelteKit will render a default error page. You can customize this error page on a per-route basis by adding an +error.svelte file. In the showcase, an error.svelte page has been added for authenticated view in case of an error. ` Advanced Routing Rest Parameters If the number of route segments is unknown, you can use spread operator syntax. This is done to implement Github’s file viewer. ` svelte-kit-scss.starter.dev/thisdot/starter.dev/blob/main/starters/svelte-kit-scss/README.md would result in the following parameters being available to the page: ` (group) layouts By default, the layout hierarchy mirrors the route hierarchy. In some cases, that might not be what you want. In the GitHub showcase, we would like an authenticated user to be able to have access to the navigation bar, error page, and user information. This is done by grouping all the relevant pages which an authenticated user can access. Grouping can also be used to tidy your file tree and ‘group’ similar pages together for easy navigation, and understanding of the project. Matching In the Github showcase, we needed to have a page to show issues and pull requests for a single repo. The route src/routes/(authenticated)/[username]/[repo]/[issues] would match /thisdot/starter.dev-github-showcases/issues or /thisdot/starter.dev-github-showcases/pull-requests but also /thisdot/starter.dev-github-showcases/anything and we don't want that. You can ensure that route parameters are well-formed by adding a matcher— which takes only issues or pull-requests, and returns true if it is valid– to your params directory. ` ` ...and augmenting your routes: ` If the pathname doesn't match, SvelteKit will try to match other routes (using the sort order specified below), before eventually returning a 404. Note: Matchers run both on the server and in the browser. Conclusion In this article, we learned about basic and advanced routing in SvelteKit by using the SvelteKit showcase example. We looked at how to work with SvelteKit's Filesystem-based router, rest parameters, and (group) layouts. If you want to learn more about SvelteKit, please check out the SvelteKit and SCSS starter kit and the SvelteKit and SCSS GitHub showcase. All the code for our showcase project is open source. If you want to collaborate with us or have suggestions, we're always welcome to new contributions. Thanks for reading! If you have any questions, or run into any trouble, feel free to reach out on Twitter....

Mar 22, 2023

5 mins

SvelteGit

“Music and code have a lot in common,” freeCodeCamp’s Jessica Wilkins on what the tech community is doing right to onboard new software engineers

Before she was a software developer at freeCodeCamp, Jessica Wilkins was a classically trained clarinetist performing across the country. Her days were filled with rehearsals, concerts, and teaching, and she hadn’t considered a tech career until the world changed in 2020. > “When the pandemic hit, most of my gigs were canceled,” she says. “I suddenly had time on my hands and an idea for a site I wanted to build.” That site, a tribute to Black musicians in classical and jazz music, turned into much more than a personal project. It opened the door to a whole new career where her creative instincts and curiosity could thrive just as much as they had in music. Now at freeCodeCamp, Jessica maintains and develops the very JavaScript curriculum that has helped her and millions of developers around the world. We spoke with Jessica about her advice for JavaScript learners, why musicians make great developers, and how inclusive communities are helping more women thrive in tech. Jessica’s Top 3 JavaScript Skill Picks for 2025 If you ask Jessica what it takes to succeed as a JavaScript developer in 2025, she won’t point you straight to the newest library or trend. Instead, she lists three skills that sound simple, but take real time to build: > “Learning how to ask questions and research when you get stuck. Learning how to read error messages. And having a strong foundation in the fundamentals” She says those skills don’t come from shortcuts or shiny tools. They come from building. > “Start with small projects and keep building,” she says. “Books like You Don’t Know JS help you understand the theory, but experience comes from writing and shipping code. You learn a lot by doing.” And don’t forget the people around you. > “Meetups and conferences are amazing,” she adds. “You’ll pick up things faster, get feedback, and make friends who are learning alongside you.” Why So Many Musicians End Up in Tech A musical past like Jessica’s isn’t unheard of in the JavaScript industry. In fact, she’s noticed a surprising number of musicians making the leap into software. > “I think it’s because music and code have a lot in common,” she says. “They both require creativity, pattern recognition, problem-solving… and you can really get into flow when you’re deep in either one.” That crossover between artistry and logic feels like home to people who’ve lived in both worlds. What the Tech Community Is Getting Right Jessica has seen both the challenges and the wins when it comes to supporting women in tech. > “There’s still a lot of toxicity in some corners,” she says. “But the communities that are doing it right—like Women Who Code, Women in Tech, and Virtual Coffee—create safe, supportive spaces to grow and share experiences.” She believes those spaces aren’t just helpful, but they’re essential. > “Having a network makes a huge difference, especially early in your career.” What’s Next for Jessica Wilkins? With a catalog of published articles, open-source projects under her belt, and a growing audience of devs following her journey, Jessica is just getting started. She’s still writing. Still mentoring. Still building. And still proving that creativity doesn’t stop at the orchestra pit—it just finds a new stage. Follow Jessica Wilkins on X and Linkedin to keep up with her work in tech, her musical roots, and whatever she’s building next. Sticker illustration by Jacob Ashley....

Apr 25, 2025

3 mins

JavaScriptSoftware Engineering

Let's innovate together!

We're ready to be your trusted technical partners in your digital innovation journey.

Whether it's modernization or custom software solutions, our team of experts can guide you through best practices and how to build scalable, performant software that lasts.

Harnessing the Power of Threlte - Building Reactive Three.js Scenes in Svelte

Introduction

Three.js: The 3D Powerhouse

Svelte Ecosystem: Svelte Cubed and Svelthree

Introducing Threlte v6: Uniting SvelteKit 1.0, Svelte 4, and TypeScript

Setting up Threlte

Option 1: Scaffold a New Threlte Project

Option 2: Manual Installation

Exploring the Boilerplate of Threlte

Heading to the Fun Stuff

Creating a Rotating Sphere Scene

1. Setting Up the Scene

2. Setting Up the Sphere

3. Setting Up the Camera and Lights

4. Interactivity: Scaling and Color Changes

Adding Navigation and Scroll Prompt in `app.svelte`

1. Importing the Canvas and Scene

2. Embedding the 3D Scene

3. Adding the Navigation Bar

4. Adding the Scroll Prompt

5. Styling the Components

Conclusion

Ian Sam Mungai

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Svelte 5 is Here!

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A Deep Dive into SvelteKit Routing with Our Starter.dev GitHub Showcase Example

“Music and code have a lot in common,” freeCodeCamp’s Jessica Wilkins on what the tech community is doing right to onboard new software engineers

Introduction

Three.js: The 3D Powerhouse

Svelte Ecosystem: Svelte Cubed and Svelthree

Introducing Threlte v6: Uniting SvelteKit 1.0, Svelte 4, and TypeScript

Setting up Threlte

Option 1: Scaffold a New Threlte Project

Option 2: Manual Installation

Exploring the Boilerplate of Threlte

Heading to the Fun Stuff

Creating a Rotating Sphere Scene

1. Setting Up the Scene

2. Setting Up the Sphere

3. Setting Up the Camera and Lights

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Adding Navigation and Scroll Prompt in app.svelte

1. Importing the Canvas and Scene

2. Embedding the 3D Scene

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4. Adding the Scroll Prompt

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Conclusion

Ian Sam Mungai

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A Deep Dive into SvelteKit Routing with Our Starter.dev GitHub Showcase Example

“Music and code have a lot in common,” freeCodeCamp’s Jessica Wilkins on what the tech community is doing right to onboard new software engineers

Adding Navigation and Scroll Prompt in `app.svelte`