Adding a Remove All Anchors.

It will remove all user anchors from the scene (anchors generated from Spatial Mapping and Surface Observer won't be removed)

Author: VincentGuigui

Assets/HoloToolkit/Utilities/Scripts/WorldAnchorManager.cs

@@ -5,6 +5,7 @@
 using UnityEngine;
 using UnityEngine.VR.WSA.Persistence;
 using UnityEngine.VR.WSA;
+using HoloToolkit.Unity.SpatialMapping;
 
 namespace HoloToolkit.Unity
 {
@@ -135,6 +136,36 @@ public void RemoveAnchor(GameObject gameObjectToUnanchor)
                 });
         }
 
+        /// <summary>
+        /// Removes all anchors from the scene and deletes them from the anchor store.
+        /// </summary>
+        public void RemoveAllAnchors()
+        {
+            // This case is unexpected, but just in case.
+            if (AnchorStore == null)
+            {
+                Debug.LogError("remove all anchors called before anchor store is ready.");
+            }
+
+            WorldAnchor[] anchors = FindObjectsOfType<WorldAnchor>();
+            SpatialMappingManager spatialMappingManager = FindObjectOfType<SpatialMappingManager>();
+
+            if (anchors != null)
+            {
+                foreach (WorldAnchor anchor in anchors)
+                {
+                    //Don't remove SpatialMapping anchors
+                    if (anchor.gameObject.transform.parent.gameObject != spatialMappingManager.gameObject)
+                        anchorOperations.Enqueue(new Unity.WorldAnchorManager.AnchorAttachmentInfo()
+                        {
+                            AnchorName = anchor.name,
+                            GameObjectToAnchor = anchor.gameObject,
+                            Operation = AnchorOperation.Delete
+                        });
+                }
+            }
+        }
+
         /// <summary>
         /// Function that actually adds the anchor to the game object.
         /// </summary>