hytopia-entities

Use this skill when the user:

• Wants to create game objects, NPCs, items, or interactive objects
• Needs to spawn or despawn entities
• Asks about entity components or behaviors
• Wants to animate entities or handle entity lifecycle
• Needs collision detection between entities
• Asks about player entities vs non-player entities

Creating an Entity

```typescript

import { Entity } from 'hytopia';

class MyEntity extends Entity {

constructor() {

super();

// Initialize entity properties

}

onSpawn() {

// Called when entity is spawned into the world

}

onDespawn() {

// Called when entity is removed from the world

}

tick(deltaTime: number) {

// Called every frame - use for continuous updates

}

}

```

Spawning Entities

```typescript

// Spawn an entity in the world

const entity = new MyEntity();

world.spawnEntity(entity, {

position: { x: 0, y: 10, z: 0 },

rotation: { x: 0, y: 0, z: 0 }

});

// Despawn when done

world.despawnEntity(entity);

```

Entity with Model

```typescript

import { Entity, Model } from 'hytopia';

class ItemEntity extends Entity {

constructor() {

super();

this.model = new Model({

modelUri: 'models/sword.gltf',

scale: 0.5

});

}

}

```

Entity Components

```typescript

import { Entity, PhysicsComponent, HealthComponent } from 'hytopia';

class EnemyEntity extends Entity {

constructor() {

super();

// Add physics

this.addComponent(new PhysicsComponent({

mass: 10,

colliders: [/ collision shapes /]

}));

// Add health

this.addComponent(new HealthComponent({

maxHealth: 100,

currentHealth: 100

}));

}

}

```

Following Player

```typescript

tick(deltaTime: number) {

const player = world.getClosestPlayer(this.position);

if (player) {

const direction = player.position.subtract(this.position).normalize();

this.position.add(direction.multiply(5 * deltaTime));

}

}

```

Projectile Entity

```typescript

class Projectile extends Entity {

velocity: Vector3;

lifetime: number = 5;

tick(deltaTime: number) {

this.position.add(this.velocity.multiply(deltaTime));

this.lifetime -= deltaTime;

if (this.lifetime <= 0) {

world.despawnEntity(this);

}

}

}

```

1. Always clean up in onDespawn() - remove event listeners, stop sounds
2. Use tick() sparingly - expensive operations every frame hurt performance
3. Pool reusable entities - don't constantly spawn/despawn the same type
4. Set proper collision layers - use layers to filter what collides with what
5. Network efficiently - only sync properties that change and need to be visible to clients

• Don't forget to call super() in constructor
• Don't modify entity properties directly on the client - server is authoritative
• Don't spawn entities before world is initialized
• Don't forget to handle entity cleanup on game end