
# Intro

The following steps will guide you through baking lightmaps for your test level with Blender.
Lightmaps can help you make unique levels by tweaking lighting and making it look good independently of the hardware.
This tutorial was made for Blender because it's easily available, but most steps can be adapted to Maya or 3DSMax.

## Modeling
Model the room using cubes.
Remove the roof.
![Modeling](/img/how_to/lightmaps/lm1-0.webp)
Model stairs in less than 40 seconds: https://www.youtube.com/watch?v=J4T256mVkS0

## Material and textures
Create 2 materials: 1 for walls and 1 for the ground.
![Material and textures](/img/how_to/lightmaps/lm2-0.webp)
Select the faces in edit mode, then click the Apply button.
![Material and textures](/img/how_to/lightmaps/lm2-1.webp)

## Lighting
Add sun light.
![Lighting](/img/how_to/lightmaps/lm3-0.webp)
Add an area light that covers the whole scene.
![Lighting](/img/how_to/lightmaps/lm3-1.webp)

## UV set
Select all faces in edit mode. Apply a box UV projection.
![UV set](/img/how_to/lightmaps/lm4-0.webp)
Go to UV edit mode. Scale the UVs up until the pixel density is good.
![UV set](/img/how_to/lightmaps/lm4-1.webp)

## 2nd UV set
Add a new UV set and set it as active.
![2nd UV set](/img/how_to/lightmaps/lm5-0.webp)
Select all faces and Lightmap Pack menu option.
![2nd UV set](/img/how_to/lightmaps/lm5-1.webp)

## Preparing shading
Add 2 UV maps: the first for the default UV set and the second for the lightmap set.
![Preparing shading](/img/how_to/lightmaps/lm6-0.webp)
![Preparing shading](/img/how_to/lightmaps/lm6-1.webp)
Create a new lightmap image with an appropriate size.
![Preparing shading](/img/how_to/lightmaps/lm6-2.webp)

## Baking
With Cycles renderer: Diffuse lighting without color.
![Baking](/img/how_to/lightmaps/lm7-0.webp)
Do not forget to save the baked image as a lightmap.

## Test Playground
Export the scene as a glb and upload it so it's available online.
Make a new Playground and copy-paste the code.
Apply the lightmap to every mesh.
![Result](/img/how_to/lightmaps/lmResult.webp)

<Playground id="#SSD1Q5#1" title="Scene with lightmap" description="Scene with lightmap"/>


## Networking

In this section, you can learn how to create networked Babylon.js experiences such as multiplayer games or remote multi-user interactions.



![Vite + Babylon.js Combo Logo](/img/how_to/using-vite/01.webp)

## What is Vite and why do you need it?

[Vite](https://vitejs.dev/) is a modern development environment that bundles and optimizes your code, launches local test servers instantly, automates more project configurations out of the box, and includes other quality-of-life improvements. In other words, it's an all-in-one tool that lets you develop Babylon.js projects locally on your computer with ease. It's intended to replace Webpack, which has a similar goal but requires more work and maintenance (especially with its config files).

Whether you're ready to graduate from playing with example projects in the [Playground](https://playground.babylonjs.com/), or if you're already a seasoned developer looking to upgrade your software stack, this guide can benefit any of your future Babylon.js projects!

## Leaving the Playground with VSCode & npm

***You can skip to Step 3 if you already have a code editor and npm installed.*** Otherwise, it's time to finally leave the Playground and learn how to create Babylon.js projects that you can publish and share anywhere. This is usually done with a code editor, a program that helps you write and manage your projects.

**(1)** Install a code editor. This tutorial uses [Visual Studio Code](https://code.visualstudio.com/) *(or [VSCodium](https://vscodium.com/))* but you can still follow along if you want to use a different one.

![VSC](/img/how_to/using-vite/02.webp)

Your code editor may look something like this when opened.

**(2)** Close your code editor and install Node.js with [one of these installers](https://nodejs.dev/en/download/) (or via your package manager if you use Linux.) Installing this gives us access to [npm](https://www.npmjs.com/), a library of Node.js packages to help you build web-based apps and keep them up-to-date. This is how we're going to install Babylon.js and Vite.

![npm test](/img/how_to/using-vite/03.webp)

You'll know if you did it right by opening Command Prompt on Windows (or Terminal on macOS/Linux) and writing `npm -v`. If the output is a version number, you're good to go.

## Setting up Vite & Babylon.js

Once you have your code editor and Node.js installed, we can begin setting up your development folder.

**(3)** Create a folder on your computer wherever you want to store your Babylon.js projects, and open it in your code editor using the menu `File` > `Open Folder`. If prompted, click on "Yes, I trust the authors." You should now have a sidebar on your left like this:

![npm test](/img/how_to/using-vite/04.webp)

**(4)** Toggle the terminal using the menu `View` > `Terminal` and enter the following commands one after the other:

- `npm i vite` *(`i` is short for `install`)*
- `npm i -D @babylonjs/core`  *(`-D` is short for `--save-dev`)*
- `npm i -D @babylonjs/inspector`

This installs Vite and some Babylon.js features in your created folder (in a subdirectory called `node_modules`).

**(5)** Now enter the command `npm init vite`. Enter the name of your Babylon.js project, such as `testProj` or whatever name you want. You can also set a package name, but the default one works fine. Choose "Vanilla" from the list that pops up, and then choose "TypeScript." (This setup also works with JavaScript, but with slightly different steps not documented here.)

![folder structure with vanilla Vite](/img/how_to/using-vite/05.webp)

Look at that! We have a new folder containing a Vite template project. You can rename the folder if you want.

## Configuring a test project

Now let's turn our vanilla Vite folder into an example Babylon.js project that you can use as a foundation for your future Vite & Babylon.js projects.

**(6)** Right-click your new folder in the left-hand side and choose `Open in Integrated Terminal`. A second tab in your terminal will open, which is pointing to your newly-generated project folder.

![new tab](/img/how_to/using-vite/06.webp)

*Note to advanced users: The reason why we didn't just `cd` into the new folder is because it's convenient to have both the root and project folders open as separate tabs in our Terminal. Doing this lets us maintain our packages in the root folder separately from the project subfolder. We can install our necessary packages once in the root folder and reference them freely in the code inside our project subfolders. NPM is smart enough to detect any packages installed in parent folders - you don't have to install them directly inside your project root directories. This is a good habit to get into instead of maintaining multiple copies of Vite and Babylon.js in every single project folder, which wastes storage space. Feel free to deviate from this structure if you'd like, though.*

**(7)** Now enter the following commands in the terminal:

- `npm i`
- `npm run dev`

The first command installs the Vite packages that still need to be in your project root folder, and the second tells Vite to run a server that tests your current code.

**(8)** Your terminal should now say that Vite is currently running. Ctrl+click on the localhost: URL to view your test server inside your browser.

![Vite success](/img/how_to/using-vite/07.webp)

If you see this screen, good job! The foundation of our Vite project is set up. Now let's make it run Babylon.js.

**(9)** Go back to your Terminal and press Ctrl+C to stop the server. (Don't forget that keyboard shortcut.) 

Now use the left-hand sidebar (and some right-clicking) to do the following:

- Delete everything inside the `public` and `src` folders
- Create a new file inside `src` called `app.ts`
- Double-click on `index.html` and `tsconfig.json`

![file tabs](/img/how_to/using-vite/08.webp)

You should now have all three of these files open.

**(10)** Copy the contents of the three code blocks below and paste them into their respective files. Save each file (Ctrl+S) after you do this.

![Picture of a file](/img/how_to/using-vite/09.webp)

This code for **app.ts** is a test scene of a sphere from [another Babylon.js tutorial](https://doc.babylonjs.com/guidedLearning/createAGame/gettingSetUp). Notice how the `import` statements at the top allow the rest of the code to function: 

```typescript
import "@babylonjs/core/Debug/debugLayer";
import "@babylonjs/inspector";
import { Engine, Scene, ArcRotateCamera, Vector3, HemisphericLight, Mesh, MeshBuilder } from "@babylonjs/core";

class App {
    constructor() {
        // create the canvas html element and attach it to the webpage
        var canvas = document.createElement("canvas");
        canvas.style.width = "100%";
        canvas.style.height = "100%";
        canvas.id = "gameCanvas";
        document.body.appendChild(canvas);

        // initialize babylon scene and engine
        var engine = new Engine(canvas, true);
        var scene = new Scene(engine);

        var camera: ArcRotateCamera = new ArcRotateCamera("Camera", Math.PI / 2, Math.PI / 2, 2, Vector3.Zero(), scene);
        camera.attachControl(canvas, true);
        var light1: HemisphericLight = new HemisphericLight("light1", new Vector3(1, 1, 0), scene);
        var sphere: Mesh = MeshBuilder.CreateSphere("sphere", { diameter: 1 }, scene);

        // hide/show the Inspector
        window.addEventListener("keydown", (ev) => {
            // Shift+Ctrl+Alt+I
            if (ev.shiftKey && ev.ctrlKey && ev.altKey && ev.keyCode === 73) {
                if (scene.debugLayer.isVisible()) {
                    scene.debugLayer.hide();
                } else {
                    scene.debugLayer.show();
                }
            }
        });

        // run the main render loop
        engine.runRenderLoop(() => {
            scene.render();
        });
    }
}
new App();
```

This code for **index.html** contains the title that will appear in the browser title bar, as well as a `<script>` tag to tell Vite which file has the main code to start our project, which is `app.ts` in our case:

```html
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>Title of Your Project</title>
    </head>
    <body>
       <script type="module" src="./src/app.ts"></script>
    </body>
</html>
```

This code for **tsconfig.json** is a slimmed-down combination of the default Vite file and the one from that other Babylon.js tutorial mentioned earlier. Each line roughly explains what each setting does. (Note that JSON files normally don't allow you to insert comments like this example here, but tsconfig.json in particular does.) You can read the [TypeScript docs](https://www.typescriptlang.org/tsconfig) if you want to learn more:

```json
{
  "compilerOptions": {
    "target": "es6", // choose our ECMA/JavaScript version (all modern browsers support ES6 so it's your best bet)
    "lib": [ // choose our default ECMA/libraries to import
      "dom", // mandatory for all browser-based apps
      "es6" // mandatory for targeting ES6
    ],
    "useDefineForClassFields": true, // enable latest ECMA runtime behavior with older ECMA/JavaScript versions (delete this line if target: "ESNext" or "ES2022"+)
    "module": "ESNext", // use the latest ECMA/JavaScript syntax for our import statements and such
    "moduleResolution": "node", // ensures we are using CommonJS for our npm packages
    "noResolve": false, // disable TypeScript from automatically detecting/adding files based on import statements and etc (it's less helpful than you think)
    "isolatedModules": true, // allows our code to be processed by other transpilers, such as preventing non-module TS files (you could delete this since we're only using base TypeScript)
    "removeComments": true, // remove comments from our outputted code to save on space (look into terser if you want to protect the outputted JS even more)
    "esModuleInterop": true, // treats non-ES6 modules separately from ES6 modules (helpful if module: "ESNext")
    "noImplicitAny": false, // usually prevents code from using "any" type fallbacks to prevent untraceable JS errors, but we'll need this disabled for our example code
    "noUnusedLocals": false, // usually raises an error for any unused local variables, but we'll need this disabled for our example code
    "noUnusedParameters": true, // raises an error for unused parameters
    "noImplicitReturns": true, // raises an error for functions that return nothing
    "skipLibCheck": true // skip type-checking of .d.ts files (it speeds up transpiling)
  },
  "include": ["src"] // specify location(s) of .ts files
}
```

**(11)** Run `npm run dev` in your terminal and Ctrl+click the localhost: link again.

![Babylon & Vite ready](/img/how_to/using-vite/10.webp)

🎉 YOU DID IT!! You just successfully created a local development environment for Babylon.js using Vite!

## Maintenance and updates

**HOWEVER,** before you continue your Babylon.js journey with your shiny new setup, here's some basic upkeep you'll have to keep in mind:

- You should occasionally run `npm up` *(short for `update`)* in the first terminal tab, which is the one for the main folder above your projects. This keeps Vite and Babylon.js updated.
- If you need to uninstall a package from Step 4 or otherwise, run `npm un <packageNameHere>` *(short for `uninstall`)* in that same main folder or terminal tab.
- Static assets such as images or 3D models should go in the `public` folder. These can then be referenced as if they're in the root folder `"./likethis.png"`.
- If you ever get stuck, reach out to [the Babylon forums](https://forum.babylonjs.com/) for help.

And that's it - you can go code now!

## Building and sharing online

...But let's say you finished making a project and you want to share it with the rest of the world. It's time to take advantage of Vite's bundling abilities and export your code into lightweight JS for the web!

Here's how:

- Make sure all your non-code assets (images, 3D models, etc.) are in the `public` folder to ensure that they end up in the final bundle.
- If it's not already open as a tab, right-click on your project's folder (not the main one) and choose `Open in Integrated Terminal`. Or just click on your second Terminal tab if you still have it.
- Run this command: `npm run build`
- Your exported code bundle is now in a folder called `dist`. Check if it works by running: `npm run preview`
- **IMPORTANT:** Once you verify this test works, open `dist/index.html` and look for any file paths that point to root with `/`. Add a period in front of all of those root paths (meaning `/assets` would become `./assets`) and save the file. For a more permanent solution, you can modify the package.json file in your project directory. Change the line: "build": "tsc && vite build" to: "build": "tsc && vite build --base=./". This will ensure that the base path is correctly set during the build process, eliminating the need to manually edit file paths in dist/index.html after each build.

![Final dist folder](/img/how_to/using-vite/11.webp)

NOW you can upload the contents of your `dist` folder to a host like GitHub Pages or Vercel to share it with the world! It'll run way faster than a project from the Playground since the code bundle only includes the parts of Babylon.js that you need, instead of the entire engine.

*Note to advanced users: if you really want to push the limits of Vite and its bundling capabilities, you can look into using Dynamic `import` Statements. This feature allows you to put import statements inside functions instead of at the top of your code, which helps reduce the overall size of your exported bundle via code-splitting. I haven't tried this feature myself, but [this overview video](https://www.youtube.com/watch?v=kwUfeWe7DCw) from Beyond Fireship is a great place to start exploring this workflow if you're interested.*

*Note to existing Vite users: you might've noticed that I instructed users to put all static assets in the `public` folder, instead of using URL-holding variables that come from having every asset as an `import` statement, as specified in [the Vite documentation](https://vitejs.dev/guide/assets.html#importing-asset-as-url). This is because we don't really have to do this when Babylon.js projects contain heavy assets like 3D models by default. The obscured filenames that result from using the Vite docs' method don't really prevent the end user from ripping assets from Babylon.js projects either. If you still want to use this "Importing Assets as URLs" workflow anyway, do note that you'll have to create a `.d.ts` file in your `src` folder and figure out [this code snippet](https://stackoverflow.com/questions/51100401/typescript-image-import#answer-51163365) to get it to work with TypeScript. As you can probably tell, I also haven't tested this method.*

## Credits

This tutorial was originally a [forum post](https://forum.babylonjs.com/t/how-to-vite-with-babylon-js-game-tutorial-series/33845) I wrote to replace Webpack in capucat's [Create A Game Tutorial Series](https://doc.babylonjs.com/guidedLearning/createAGame), but I was told to turn it into an article for the docs, so here we are. Thank you PirateJC for requesting this write-up! I think it turned out great.

***Written by [wavetro](https://wavetro.net/)***

*Last updated: 2022-SEP-22*


Level prototyping using baked lightmaps

Modeling

Material and textures

Lighting

UV set

2nd UV set

Preparing shading

Baking

Test Playground