There is a port of this by Phaser:
What would be the process for implementing my own physics wrapper for the phaser js port?
I thought there used to be docs on using your own physics engine or creating a custom implementation but I cant find that anywhere now.
Implementing your own physics engine was possible for Physics v1 but it’s deprecated now.
The easiest way to integrate a new engine is to make a copy of Babylon.js/packages/dev/core/src/Physics/v2/Plugins/havokPlugin.ts at master · BabylonJS/Babylon.js · GitHub in the same folder, do the proper imports in index.ts and then replace functions 1 by 1 excluding private ones.
Concepts are similar: rigid bodies, shape, constraint, etc
For example, this method that creates a shape depending in a shape type would be pretty similar with a switch/case but functions starting with HP_Shape_... would be the Box2D equivalent. Babylon.js/packages/dev/core/src/Physics/v2/Plugins/havokPlugin.ts at 317f0a787323a430784cf0ea0984245a819fcd19 · BabylonJS/Babylon.js · GitHub
Oh man, so this is an actual project… sheeeesh ok thanks for the insight.
I started making just a wrapper to see how hard this would be.
And its going to be fairly simple actually.
export class PhaserBox2dWrapper{
public get scene(){
return this._scene
}
public world: Ib2World
private _engineRef: AbstractEngine
constructor(private _scene: Scene){
this.world = CreateWorld({worldDef: b2DefaultWorldDef()})
// this.world.locked = false
this._engineRef = this._scene.getEngine()
this._scene.onBeforeRenderObservable.add(()=>{
this.update()
})
}
public update(){
const deltaTime = this._engineRef.getDeltaTime()
WorldStep({worldId: this.world.worldId, deltaTime})
}
public addBodyToNode(node: TransformNode, options:{
type: 'static' | 'dynamic',
position: Vector2,
size: number | Vector2,
restitution: number,
density: number,
friction: number,
}){
const body = CreateBoxPolygon({
position: new b2Vec2(options.position.x, options.position.y),
type: options.type === 'static' ? b2BodyType.b2_staticBody : b2BodyType.b2_dynamicBody,
size: options.size instanceof Vector2 ? new b2Vec2(options.size.x * 0.5, options.size.y * 0.5) : options.size * 0.5,
density: options.density,
friction: options.friction,
worldId: this.world.worldId,
})
this._scene.onBeforeRenderObservable.add(()=>{
const pos = b2Body_GetPosition(body.bodyId)
const rot = b2Body_GetRotation(body.bodyId)
node.position.copyFromFloats(pos.x, pos.y, 0)
node.rotation.z = b2Rot_GetAngle(rot)
})
}
}
Is all it took to support boxes.
Took about a hour today after work and was able to get most of the core shapes supported along with debug methods.
This is actually way easier than I thought.
I knew about Box2D Web, but I didn’t know about Phaser Box2D. Thank you for letting me know.
I don’t know if it will be helpful, but here is a sample of Babylon.js + Box2D Web. (Actually, Claude.AI told me about it.)
That’s amazing!
