fix(Interaction): ensure touched object is always set after quick grab

There was an issue when grabbing and releasing an object then quickly
grabbing again would leave the touchedObject in a delayed state of
not being touched, meaning the use method on an object would not
trigger because it thought the object being grabbed wasn't being
touched. It would catch up a second or so later, but meant that
objects would feel like they couldn't be used on first pick up.

This commit now resolves the issue by checking on the use method if
the touched object is null then do a sanity check on the grabbed
object.

Assets/SteamVR_Unity_Toolkit/Scripts/VRTK_InteractTouch.cs

@@ -21,7 +21,6 @@ public struct ObjectInteractEventArgs
     [RequireComponent(typeof(VRTK_ControllerActions))]
     public class VRTK_InteractTouch : MonoBehaviour
     {
-
         public bool hideControllerOnTouch = false;
         public float hideControllerDelay = 0f;
         public Color globalTouchHighlightColor = Color.clear;
@@ -102,6 +101,11 @@ private void Start()
             CreateControllerRigidBody();
         }
 
+        private void OnTriggerEnter(Collider collider)
+        {
+            OnTriggerStay(collider);
+        }
+
         private void OnTriggerStay(Collider collider)
         {
             if (touchedObject == null && IsObjectInteractable(collider.gameObject))
@@ -140,35 +144,42 @@ private void OnTriggerStay(Collider collider)
             }
         }
 
-        private void OnTriggerExit(Collider collider)
+        private bool IsColliderChildOfTouchedObject(GameObject collider)
         {
-            if (touchedObject == null)
+            if (touchedObject != null && collider.GetComponentInParent<VRTK_InteractableObject>() && collider.GetComponentInParent<VRTK_InteractableObject>().gameObject == touchedObject)
             {
-                return;
+                return true;
             }
+            return false;
+        }
 
-            if (IsObjectInteractable(collider.gameObject))
+        private void OnTriggerExit(Collider collider)
+        {
+            if(touchedObject != null && (touchedObject == collider.gameObject || IsColliderChildOfTouchedObject(collider.gameObject)))
             {
-                GameObject untouched;
-                if (collider.gameObject.GetComponent<VRTK_InteractableObject>())
+                if (IsObjectInteractable(collider.gameObject))
                 {
-                    untouched = collider.gameObject;
+                    GameObject untouched;
+                    if (collider.gameObject.GetComponent<VRTK_InteractableObject>())
+                    {
+                        untouched = collider.gameObject;
+                    }
+                    else
+                    {
+                        untouched = collider.gameObject.GetComponentInParent<VRTK_InteractableObject>().gameObject;
+                    }
+
+                    OnControllerUntouchInteractableObject(SetControllerInteractEvent(untouched.gameObject));
+                    untouched.GetComponent<VRTK_InteractableObject>().ToggleHighlight(false);
+                    untouched.GetComponent<VRTK_InteractableObject>().StopTouching(this.gameObject);
                 }
-                else
+
+                if (hideControllerOnTouch)
                 {
-                    untouched = collider.gameObject.GetComponentInParent<VRTK_InteractableObject>().gameObject;
+                    controllerActions.ToggleControllerModel(true, touchedObject);
                 }
-
-                OnControllerUntouchInteractableObject(SetControllerInteractEvent(untouched.gameObject));
-                untouched.GetComponent<VRTK_InteractableObject>().ToggleHighlight(false);
-                untouched.GetComponent<VRTK_InteractableObject>().StopTouching(this.gameObject);
-            }
-
-            if (hideControllerOnTouch)
-            {
-                controllerActions.ToggleControllerModel(true, touchedObject);
+                touchedObject = null;
             }
-            touchedObject = null;
         }
 
         private void CreateTouchCollider(GameObject obj)

Assets/SteamVR_Unity_Toolkit/Scripts/VRTK_InteractUse.cs

@@ -150,9 +150,23 @@ private void UnuseInteractedObject()
             }
         }
 
+        private GameObject GetFromGrab()
+        {
+            if (this.GetComponent<VRTK_InteractGrab>())
+            {
+                return this.GetComponent<VRTK_InteractGrab>().GetGrabbedObject();
+            }
+            return null;
+        }
+
         private void DoStartUseObject(object sender, ControllerInteractionEventArgs e)
         {
             GameObject touchedObject = interactTouch.GetTouchedObject();
+            if(touchedObject == null)
+            {
+                touchedObject = GetFromGrab();
+            }
+
             if (touchedObject != null && interactTouch.IsObjectInteractable(touchedObject))
             {
                 UseInteractedObject(touchedObject);