Merge pull request #162 from google/ux-intersection-overriding

Support UX intersection check overriding.

Author: qxziuan

src/ux/UX.ts

@@ -125,10 +125,7 @@ export class UX {
     const id = controller.userData.id;
     this.initializeVariablesForId(id);
 
-    if (
-      intersection.object === this.parent ||
-      intersection.object === (this.parent as Partial<View>).mesh
-    ) {
+    if (this.isRelevantIntersection(intersection)) {
       this.hovered[id] = true;
       this.selected[id] = controller.userData.selected;
       if (intersection.uv) {
@@ -159,6 +156,20 @@ export class UX {
     }
   }
 
+  /**
+   * Checks if the intersection object belongs to this UX's attached Script.
+   * Allow overriding this function for more complex objects with multiple
+   * meshes.
+   * @param intersection - The raycast intersection to check.
+   * @returns True if the intersection is relevant to this UX's parent object.
+   */
+  isRelevantIntersection(intersection: THREE.Intersection): boolean {
+    return (
+      intersection.object === this.parent ||
+      intersection.object === (this.parent as Partial<View>).mesh
+    );
+  }
+
   /**
    * Resets the hover and selection states for all controllers. This is
    * typically called at the beginning of each frame.