Script Examples

Basic component

import { Behaviour, serializable } from "@needle-tools/engine"
import { Object3D } from "three"

export class MyComponent extends Behaviour {

    @serializable(Object3D)
    myObjectReference?: Object3D;

    start() {
        console.log("Hello world", this);
    }

    update() {
        // called every frame
    }
}

see scripting for all component events

Reference an Object from Unity

import { Behaviour, serializable } from "@needle-tools/engine";
import { Object3D } from "three"

export class MyClass extends Behaviour {
    // this will be a "Transform" field in Unity
    @serializable(Object3D) 
    myObjectReference: Object3D | null = null;
    
    // this will be a "Transform" array field in Unity
    // Note that the @serializable decorator contains the array content type! (Object3D and not Object3D[])
    @serializable(Object3D) 
    myObjectReferenceList: Object3D[] | null = null;
} 

Reference and load an asset from Unity (Prefab or SceneAsset)

import { Behaviour, serializable, AssetReference } from "@needle-tools/engine";

export class MyClass extends Behaviour {

    // if you export a prefab or scene as a reference from Unity you'll get a path to that asset
    // which you can de-serialize to AssetReference for convenient loading
    @serializable(AssetReference)
    myPrefab?: AssetReference;
    
    async start() {
      // directly instantiate
      const myInstance = await this.myPrefab?.instantiate();

      // you can also just load and instantiate later
      // const myInstance = await this.myPrefab.loadAssetAsync();
      // this.gameObject.add(myInstance)
      // this is useful if you know that you want to load this asset only once because it will not create a copy
      // since ``instantiate()`` does create a copy of the asset after loading it
    }  
} 

Reference and load scenes from Unity

import { Behaviour, serializable, AssetReference } from "@needle-tools/engine";

export class LoadingScenes extends Behaviour {
    // tell the component compiler that we want to reference an array of SceneAssets
    // @type UnityEditor.SceneAsset[]
    @serializable(AssetReference)
    myScenes?: AssetReference[];

    async awake() {
        if (!this.myScenes) {
            return;
        }
        for (const scene of this.myScenes) {
            // check if it is assigned in unity
            if(!scene) continue;
            // load the scene once
            const myScene = await scene.loadAssetAsync();
            // add it to the threejs scene
            this.gameObject.add(myScene);
            
            // of course you can always just load one at a time
            // and remove it from the scene when you want
            // myScene.removeFromParent();
            // this is the same as scene.asset.removeFromParent()
        }
    }

    onDestroy(): void {
        if (!this.myScenes) return;
        for (const scene of this.myScenes) {
            scene?.unload();
        }
    }
} 

Receive Clicks on Objects

import { Behaviour } from "@needle-tools/engine";
import { IPointerClickHandler, PointerEventData } from "@needle-tools/engine/engine-components/ui/PointerEvents";

export class ClickExample extends Behaviour implements IPointerClickHandler {

    // Make sure to have an ObjectRaycaster component in the parent hierarchy
    onPointerClick(_args: PointerEventData) {
        console.log("Clicked", this.name);
    }
}

Create and invoke a UnityEvent

import { Behaviour, serializable, EventList } from "@needle-tools/engine"

export class MyComponent extends Behaviour {

    @serializable(EventList)
    myEvent? : EventList;

    start() {
        this.myEvent?.invoke();
    }
}

Declare a custom event type

import { Behaviour, EventList, GameObject, serializeable } from "@needle-tools/engine";

// Documentation → https://docs.needle.tools/scripting

export class CustomEventCaller extends Behaviour {

    // The next line is not just a comment, it defines 
    // a specific type for the component generator to use.

    //@type UnityEngine.Events.UnityEvent<string, UnityEngine.GameObject>
    @serializeable(EventList)
    myEvent: EventList;

    // just for testing - could be when a button is clicked, etc.
    start() {
        this.myEvent.invoke("Hello", this.gameObject);
    }
}

export class CustomEventReceiver extends Behaviour {

    logStringAndObject(str : string, go : GameObject) {
        console.log("From Event: ", str, go);
    }
}

Example use: