aframe-ar/src/ar-raycaster.js

Basic A-Frame support for the new three.ar.js library and WebARonARKit/Core browsers, as well as WebXR Viewer.

// ar-raycaster modifies raycaster to append AR hit, if any.
// But note that current AR hit API does not support orientation as input.
AFRAME.registerComponent('ar-raycaster', {      
  dependencies: ['raycaster'],
        
  schema: {
    x: {default: 0.5},
    y: {default: 0.5},
    el: {type: 'selector'}
  },
        
  init: function () {
    // HACK: monkey-patch raycaster to append AR hit result
    this.raycaster = this.el.components['raycaster'].raycaster;
    this.raycasterIntersectObjects = this.raycaster.intersectObjects.bind(this.raycaster);
    this.raycaster.intersectObjects = this.intersectObjects.bind(this);
  },
        
  update: function (oldData) {
    if (!this.data.el) {
      // If not given some other element, return hit against the scene.
      // HACK: But that means we need its object3D to have an el.
      if (!this.el.sceneEl.object3D.el) {
        this.el.sceneEl.object3D.el = this.el.sceneEl;
      }
    }
  },
        
  intersectObjects: function (objects, recursive) {
    var results = this.raycasterIntersectObjects(objects, recursive);
    // Tack on AR hit result, if any.
    return results.concat(this.hitAR());
  },        
        
  hitAR: function () {
    var whichar = this.checkWhichAR();
    if (!whichar || !whichar.arDisplay) { return []; }
    var x = this.data.x;
    var y = this.data.y;
    if (arguments.length >= 2) {
      x = arguments[0];
      y = arguments[1];
    }
    return whichar.hitAR(x, y, this.data.el, this.el);
  },

  checkWhichAR: function () {
    if (!this.whichar) {
      var whichar = this.el.sceneEl.components['three-ar'];
      if (!whichar || !whichar.arDisplay) {
        whichar = this.el.sceneEl.components['mozilla-xr-ar'];
      }
      if (!whichar || !whichar.arDisplay) { return; }
      this.whichar = whichar;
    }
    return this.whichar;
  }
});