Three JS Multiplayer Game Demo

Online demo

Small demo here : NotBlox.online

Hosted on an european server, there is no client side prediction, so the game may be laggy if you are far from the server.

Controls

• W : Forward
• S : Backward
• A : Left
• D : Right
• Space : Jump
• Mouse Left click : Rotate screen

Features

• Multiplayer
• Only TypeScript
• 3D Physics (Rapier.js)
• Vanilla Three.js
• Server Authoritative
• ECS (Entity Component System) with Network Sync (NetworkComponent)
• Delta Compression (needs rework)
• Interpolation
• Fast to load (small assets)
• Shared code between server and client (useful for component replication)
• Trimesh Collider

Why ?

Browser games are fun, but most of them are Unity WebGL exports that take a long time to load. I wanted to create a simple multiplayer game engine using Three.js and my own ECS. This project has in mind to be a simple and fast game engine that can be used to create simple multiplayer games with the modularity of ECS.

Multiplayer GTA-like ?

I'm thinking about creating a GTA-like game with this engine. It would be a simple game with a city, cars, and players. The game would be server-authoritative, and the server would be able to spawn cars, NPCs, and other entities. The game would be a simple sandbox game where players can interact with each other and the environment. Inspiration : https://github.com/swift502/Sketchbook

Demo (Click on the images to see the video)

How to run locally

Back-end

Comment the NODE_ENV=production & FRONTEND_URL line in the back/.env file

It should look like this :

# NODE_ENV=production
# Comment to run in development mode

# FRONTEND_URL=https://www.notblox.online
# Only accept websocket connections from this URL
# Comment to accept connections from any URL

  cd back
  npm install
  npm run dev

Front-end

Comment the NEXT_PUBLIC_SERVER_URL variable in front/.env.local, it will default to localhost

It should look like this :

# NEXT_PUBLIC_SERVER_URL=https://www.notblox.online
# Only accept websocket connections from this URL
# Comment to accept connections from any URL

  cd front
  npm install
  npm run dev

Go on your browser to http://localhost:4000/

How to change the map

Maps are GLB/GLTF files. The back-end approximates a Trimesh Collider based on the map, which is rendered on the client.

To change the map, update the URL in back/src/scripts/defaultScript.js:

new MapWorld('https://myaudio.nyc3.cdn.digitaloceanspaces.com/aqsworld.glb') // Change this URL to your map

---

How to Host Your Assets for Free Without a S3 Bucket

You can host your assets for free using GitHub and Githack. Here's how:

1. Create a repository on GitHub, e.g., Notblox-Assets.
2. Use Githack to serve your assets via CDN: Setup Githack.

Then, update the URL in defaultScript.js:

new MapWorld(
  'https://rawcdn.githack.com/iErcann/Notblox-Assets/d66f6da91bb7f025c90aa9f6eb24b99e997efa38/BasicWorld.glb'
) // Change this URL to your map

---

How to Point the Map to a Local File (For Testing)

For local testing, place the map .glb under the front/public/assets folder and use:

new MapWorld('http://localhost:4001/BasicWorld.glb')

Make sure to run the front-end with npm run dev to serve the local file.

Blender: How to Export a Map Correctly

1. Apply All Transforms

• Press CTRL-A and select "All Transforms" to apply all transformations.

2. Clear Parents

• Press A to select all objects, then ALT-P and choose "Clear Parent" to remove all parent relationships.

3. Export with Compression

• Choose GLB/GLTF export.

• Activate compression.

Current Event system (might change!)

Is it better design to store event effects within an Entity itself, or within a system?

If you are using event queues anyway, you can also do them properly. With one global EventManager system which receives all events. Systems can subscribe to events they are interested in and then the EventManager will put those events into their event queues.

• Component can also be a NetworkComponent. This means it can be sent over the network to be replicated by the clients.

Shared

// Shared component between client & back
export class ColorComponent extends NetworkComponent {
  constructor(entityId: number, public color: string);
  deserialize(data: SerializedColorComponent);
  serialize(): SerializedColorComponent;
}

Back

The back-end need to pass some events; This is achieved with the event components (example: EventColorComponent) that are only used once per ECS loop and then removed from the EventQueue entity.

// Creating a color change event on the back
EventSystem.addEvent(new ColorEvent(yourEntity.id, '#FFFFFF'))

It can be received by any system, here ColorEventSystem :

The ColorComponent is updated:

export class ColorEventSystem {
  update(entities: Entity[]) {
    const eventColors = EventSystem.getEvents(ColorEvent)

    for (const eventColor of eventColors) {
      const entity = EntityManager.getEntityById(entities, eventColor.entityId)
      if (!entity) return

      const colorComponent = entity.getComponent(ColorComponent)
      if (!colorComponent) return

      if (colorComponent && eventColor) {
        colorComponent.color = eventColor.color
        colorComponent.updated = true
      }
    }
  }
}

Client (front-end)

The component is replicated by the client with the SyncComponentsSystem.ts, then it uses the front-end version of SyncColorSystem to actually change the color of the mesh, you could incorporate more checks here depending on other components

export class SyncColorSystem {
  update(entities: Entity[]) {
    for (const entity of entities) {
      const colorComponent = entity.getComponent(ColorComponent)
      const meshComponent = entity.getComponent(MeshComponent)
      if (colorComponent && meshComponent && colorComponent.updated) {
        meshComponent.mesh.material = new THREE.MeshPhongMaterial({
          color: colorComponent.color,
        })
      }
    }
  }
}

You like this project or want to talk about Three.js games ?

Discord https://discord.gg/aEBXPtFwgU 👀

Shared file import Error .js files fix

Link to GitHub Discussion

Asset Credits

San Andreas Map : https://skfb.ly/oJSPS

Kenney Assets https://www.kenney.nl/

⚠️ This project is not related to any crypto project

There have been some modifications of Notblox running online to promote cryptocurrencies, it is not made by me

The point of notblox was to show a demo of a multiplayer 3d game with three.js, fully open-source

The only version I run is notblox.online, all the other modifications are made by third-parties