Interface WorldQueryModuleWearable Only

Provides access to WorldQuery api which performs hit test for real surfaces to sample the depth and normal at a certain location.

Example

// import required modules
const WorldQueryModule = require("LensStudio:WorldQueryModule")
const EPSILON = 0.01;
const RAY_LENGTH = 1000;

@component
export class NewScript extends BaseScriptComponent {

    private hitTestSession;
    private transform: Transform;
    private cameraTransform: Transform;

    @input
    targetObject: SceneObject;

    @input
    camera: Camera;

    @input
    filterEnabled: boolean;

    onAwake() {
        // create new hit session
        this.hitTestSession = this.createHitTestSession(this.filterEnabled);

        this.transform = this.targetObject.getTransform();
        this.cameraTransform = this.camera.getSceneObject().getTransform();
        // disable target object when surface is not detected
        this.targetObject.enabled = false;
        // create update event
        this.createEvent("UpdateEvent").bind(this.onUpdate.bind(this));
    }


    createHitTestSession(filterEnabled) {
        // create hit test session with options
        let options = HitTestSessionOptions.create();
        options.filter = filterEnabled;


        let session = WorldQueryModule.createHitTestSessionWithOptions(options);
        return session;
    }


    onHitTestResult(results) {
        if (results === null) {
            this.targetObject.enabled = false;
        } else {
            this.targetObject.enabled = true;
            // get hit information
            const hitPosition = results.position;
            const hitNormal = results.normal;


            // identifying the direction the object should look at based on the normal of the hit location.

            let lookDirection;
            if (1 - Math.abs(hitNormal.normalize().dot(vec3.up())) < EPSILON) {
                lookDirection = vec3.forward();
            } else {
                lookDirection = hitNormal.cross(vec3.up());
            }


            const toRotation = quat.lookAt(lookDirection, hitNormal);
            // set position and rotation
            this.targetObject.getTransform().setWorldPosition(hitPosition);
            this.targetObject.getTransform().setWorldRotation(toRotation);
        }
    }


    onUpdate() {
        let rayStart = this.cameraTransform.getWorldPosition();
        let rayEnd = rayStart.add(this.cameraTransform.forward.uniformScale(RAY_LENGTH));
        this.hitTestSession.hitTest(rayStart, rayEnd, this.onHitTestResult.bind(this));
    }
}

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