https://github.com/corollarium/babylon-boids
A boids library for BabylonJS
https://github.com/corollarium/babylon-boids
babylonjs boids webgl
Last synced: 8 months ago
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A boids library for BabylonJS
- Host: GitHub
- URL: https://github.com/corollarium/babylon-boids
- Owner: Corollarium
- License: mit
- Created: 2020-02-19T13:39:04.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2023-03-04T06:06:42.000Z (over 3 years ago)
- Last Synced: 2025-10-31T01:59:09.982Z (8 months ago)
- Topics: babylonjs, boids, webgl
- Language: JavaScript
- Size: 943 KB
- Stars: 6
- Watchers: 1
- Forks: 1
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# babylon-boids
A [boids](https://en.wikipedia.org/wiki/Boids) library for [BabylonJS](https://babylonjs.com/). Used in the [Laje de Santos Virtual Dive project](https://corollarium.github.io/lajevr/). Check:
- [Demo with boxes](https://corollarium.github.io/babylon-boids/boxes.html)
- [Demo with scary sharks](https://corollarium.github.io/babylon-boids/fish.html)
## How to use it
First create your `BoidsManager` object and associate it with your meshes.
```js
function loadCubes (total, scene) {
// instantiate our boids manager. Note it doesn't handle the meshes themselves, only the total meshes.
const boidsManager = new BoidsManager(total, new BABYLON.Vector3(0.0, 0.0, 0.0), 10.0, 10.0);
// so let's now create our meshes
const models = [];
const brickMaterial = new BABYLON.StandardMaterial('brickMaterial', scene);
brickMaterial.diffuseTexture = new BABYLON.Texture('does_not_exist');
for (let i = 0; i < total; i++) {
// create a box
const box = BABYLON.MeshBuilder.CreateBox(
'box' + i,
{
width: 0.3, height: 0.5, depth: 1.0
}
);
// associate box to boid data.
box.boid = boidsManager.boids[i];
box.material = brickMaterial;
models.push(box);
}
// if you want to get a debug with bounding spheres and velocity vectors
boidsManager.showDebug();
boidsManager.gui(scene);
// so we return 3 things here: the models, the boidsManager, and an update callback
// for the render loop.
return {
models,
boidsManager,
update: ((_boids, _models) => {
return (deltaTime) => {
// update the boid simulation first
_boids.update(deltaTime);
// now apply the calculated positions/orientations to the meshes
_models.forEach((m) => {
m.position.copyFrom(m.boid.position);
m.setDirection(m.boid.orientation);
});
};
})(boidsManager, models)
};
}
```
Remember to call the update function
```js
// create a boid block with 20 boids
const myBoids = loadCubes(20, scene);
// Register a render loop to repeatedly render the scene
engine.runRenderLoop(() => {
const timeDiff = engine.getDeltaTime() / 1000.0;
// update boids
myBoids.update(timeDiff);
scene.render();
});
```
## API
### `constructor(total, center, initialRadius = 1.0, boundRadiusScale = 100.0, initialVelocity = null)`
Constructor. See [parameters](#Parameters) for class parameters that can be accessed and changed directly.
`int total`: Total number of boids in simulation
`BABYLON.vector3 center`: The center point of the boid volume.
`float initialRadius`: The radius of the initial boid volume. Boids are distributed randomly within this volume from `center` when created.
`float boundRadiusScale`: The bounding volume for the total simulation. Boids are restricted to this volume from `center`.
`BABYLON.vector3 initialVelocity`: The inicial velocity for the boids. A small randomness factor is added to each boid.
### `update(deltaTime)`
Updates the boids. Call on every render loop.
`Number deltaTime` The time since last frame in seconds.
### `addForce(c)`
Adds a force callback function. This enables you to change the simulation with your own forces. Called fr
`callback c` A valid JS function, called on `update()` for each boid. Receives as parameters: `(BoidsManager, Boid)`
### `showDebug(scene)`
Turns on debug visual helpers.
`BABYLON.scene scene` The scene object.
### `hideDebug(scene)`
Turns off debug visual helpers.
`BABYLON.scene scene` The scene object.
### `gui(scene)`
Turns on a panel to visually change the boid simulation parameters.
`BABYLON.scene scene` The scene object.
## Parameters
All accessed on the BoidsManager instance.
`cohesion` Cohesion factor.
`separation` Separation factor.
`alignment` Alignment factor.
`separationMinDistance` The
`maxSpeed` The maximum allowed speed for a boid, in units per second.
`boundsMin` The minimum bounds for the valid boid volume.
`boundsMax` The maximum bounds for the valid boid volume.
## LICENSE
[MIT](LICENSE)