diff --git a/src/Aardvark.Data.Points.Base/Storage.cs b/src/Aardvark.Data.Points.Base/Storage.cs
index 899780dd..84139397 100644
--- a/src/Aardvark.Data.Points.Base/Storage.cs
+++ b/src/Aardvark.Data.Points.Base/Storage.cs
@@ -46,7 +46,9 @@ public class Storage : IDisposable
         /// <summary>add(key, value, create)</summary>
         public readonly Action<string, object, Func<byte[]>> f_add;
 
-        /// <summary></summary>
+        /// <summary>
+        /// Returns null if key does not exist.
+        /// </summary>
         public readonly Func<string, byte[]?> f_get;
 
         /// <summary></summary>
diff --git a/src/Aardvark.Geometry.PointSet/Octrees/Export.cs b/src/Aardvark.Geometry.PointSet/Octrees/Export.cs
index 097ff4d6..f27cd7d3 100644
--- a/src/Aardvark.Geometry.PointSet/Octrees/Export.cs
+++ b/src/Aardvark.Geometry.PointSet/Octrees/Export.cs
@@ -84,8 +84,7 @@ public static ExportPointSetInfo ExportPointSet(
 
             if (pointSet == null)
             {
-                var (success, root) = self.TryGetPointCloudNode(pointSetId);
-                if (success)
+                if (self.TryGetPointCloudNode(pointSetId, out var root))
                 {
                     var ersatzPointSetKey = Guid.NewGuid().ToString();
                     Report.Warn($"Created PointSet with key '{ersatzPointSetKey}'.");
diff --git a/src/Aardvark.Geometry.PointSet/Octrees/IPointCloudNodeExtensions.cs b/src/Aardvark.Geometry.PointSet/Octrees/IPointCloudNodeExtensions.cs
index 00ae7300..51d7fc59 100644
--- a/src/Aardvark.Geometry.PointSet/Octrees/IPointCloudNodeExtensions.cs
+++ b/src/Aardvark.Geometry.PointSet/Octrees/IPointCloudNodeExtensions.cs
@@ -73,7 +73,7 @@ public static void ForEachNode(
                     var n = self.Subnodes[i];
                     if (n != null)
                     {
-                        if (n.TryGetValue(out var node)) node.ForEachNode(outOfCore, action);
+                        if (n.TryGetFromCache(out var node)) node.ForEachNode(outOfCore, action);
                     }
                 }
             }
@@ -148,7 +148,7 @@ public static void ForEachIntersectingNode(
                     var n = self.Subnodes[i];
                     if (n != null)
                     {
-                        if (n.TryGetValue(out var node))
+                        if (n.TryGetFromCache(out var node))
                         {
                             node.ForEachIntersectingNode(outOfCore, hull, doNotTraverseSubnodesWhenFullyInside, action, ct);
                         }
@@ -424,7 +424,7 @@ long FastCount(Guid key)
                         var n = self.Subnodes[i];
                         if (n != null)
                         {
-                            if (n.TryGetValue(out var node)) count += node.CountNodes(outOfCore);
+                            if (n.TryGetFromCache(out var node)) count += node.CountNodes(outOfCore);
                         }
                     }
                 }
@@ -455,7 +455,7 @@ public static long CountLeafNodes(this IPointCloudNode self, bool outOfCore)
                     var n = self.Subnodes[i];
                     if (n != null)
                     {
-                        if (n.TryGetValue(out var node)) count += node.CountLeafNodes(outOfCore);
+                        if (n.TryGetFromCache(out var node)) count += node.CountLeafNodes(outOfCore);
                     }
                 }
             }
@@ -489,7 +489,7 @@ public static long GetMinimumLeafPointCount(this IPointCloudNode self, bool outO
                         var n = self.Subnodes[i];
                         if (n != null)
                         {
-                            if (n.TryGetValue(out var node))
+                            if (n.TryGetFromCache(out var node))
                             {
                                 var x = node.GetMinimumLeafPointCount(outOfCore);
                                 if (x < min) min = x;
@@ -528,7 +528,7 @@ public static long GetMaximumLeafPointCount(this IPointCloudNode self, bool outO
                         var n = self.Subnodes[i];
                         if (n != null)
                         {
-                            if (n.TryGetValue(out var node))
+                            if (n.TryGetFromCache(out var node))
                             {
                                 var x = node.GetMinimumLeafPointCount(outOfCore);
                                 if (x > max) max = x;
@@ -576,7 +576,7 @@ public static int GetMinimumTreeDepth(this IPointCloudNode self, bool outOfCore)
                     var n = self.Subnodes[i];
                     if (n != null)
                     {
-                        if (n.TryGetValue(out var node))
+                        if (n.TryGetFromCache(out var node))
                         {
                             var x = node.GetMinimumTreeDepth(outOfCore);
                             if (x < min) min = x;
@@ -615,7 +615,7 @@ public static int GetMaximiumTreeDepth(this IPointCloudNode self, bool outOfCore
                     var n = self.Subnodes[i];
                     if (n != null)
                     {
-                        if (n.TryGetValue(out var node))
+                        if (n.TryGetFromCache(out var node))
                         {
                             var x = node.GetMaximiumTreeDepth(outOfCore);
                             if (x > max) max = x;
@@ -660,7 +660,7 @@ private static void GetAverageTreeDepth(this IPointCloudNode self, bool outOfCor
                     var n = self.Subnodes[i];
                     if (n != null)
                     {
-                        if (n.TryGetValue(out var node)) node.GetAverageTreeDepth(outOfCore, depth, ref sum, ref count);
+                        if (n.TryGetFromCache(out var node)) node.GetAverageTreeDepth(outOfCore, depth, ref sum, ref count);
                     }
                 }
             }
diff --git a/src/Aardvark.Geometry.PointSet/Octrees/Inline.cs b/src/Aardvark.Geometry.PointSet/Octrees/Inline.cs
index f63aefc8..48866103 100644
--- a/src/Aardvark.Geometry.PointSet/Octrees/Inline.cs
+++ b/src/Aardvark.Geometry.PointSet/Octrees/Inline.cs
@@ -306,7 +306,7 @@ static IEnumerable<InlinedNode> EnumerateRecImpl(IPointCloudNode node, HashSet<G
                 {
                     foreach (var x in node.Subnodes)
                     {
-                        if (x != null && x.TryGetValue(out var subnode))
+                        if (x != null && x.TryGetFromCache(out var subnode))
                         {
                             foreach (var n in EnumerateRecImpl(subnode, survive, config, processedNodeCount)) yield return n;
                         }
@@ -384,7 +384,7 @@ HashSet<Guid> survive
             var hasColors = node.HasColors;
             var hasClassifications = node.HasClassifications;
             var hasIntensities = node.HasIntensities;
-            var subnodes = node.Subnodes?.Map(x => x?.TryGetValue());
+            var subnodes = node.Subnodes?.Map(x => x?.Value);
             var isNotLeaf = !node.IsLeaf;
 
             var ps = default(V3f[]);
@@ -418,7 +418,7 @@ static byte[] rescaleIntensities(int[] js32)
             if (config.Collapse && isNotLeaf)
             {
                 if (subnodes == null) throw new Exception("Assertion failed. Error 42565d4a-2e91-4961-a310-095b503fe6f1.");
-                var nonEmptySubNodes = subnodes.Where(x => x.HasValue && x.Value.hasValue).Select(x => x!.Value.value!).ToArray();
+                var nonEmptySubNodes = subnodes.Where(x => x != null).Select(x => x!).ToArray();
 
                 ps = nonEmptySubNodes
                     .SelectMany(n =>
@@ -457,9 +457,9 @@ static byte[] rescaleIntensities(int[] js32)
                 var guids2 = subnodes
                     .Map(nref =>
                     {
-                        if (nref.HasValue && nref.Value.hasValue)
+                        if (nref != null)
                         {
-                            var n = nref.Value.value!;
+                            var n = nref!;
                             return !n.IsLeaf ? n.Id : Guid.Empty;
                         }
                         else
@@ -471,7 +471,7 @@ static byte[] rescaleIntensities(int[] js32)
                 var isNewLeaf = guids2.All(k => k == Guid.Empty);
                 if (!isNewLeaf)
                 {
-                    subnodeGuids = subnodes.Map(x => x.HasValue && x.Value.hasValue ? x.Value.value!.Id : Guid.Empty);
+                    subnodeGuids = subnodes.Map(x => x != null ? x.Id : Guid.Empty);
                     foreach (var g in nonEmptySubNodes) survive.Add(g.Id);
                 }
             }
@@ -479,14 +479,14 @@ static byte[] rescaleIntensities(int[] js32)
             {
                 if (isNotLeaf)
                 {
-                    subnodeGuids = subnodes.Map(x => x.HasValue && x.Value.hasValue ? x.Value.value!.Id : Guid.Empty);
+                    subnodeGuids = subnodes.Map(x => x != null ? x.Id : Guid.Empty);
                 }
 
                 ps = node.Positions.Value!;
                 if (hasColors) cs = node.Colors!.Value;
                 if (hasClassifications) ks = node.Classifications!.Value;
                 if (hasIntensities) js = rescaleIntensities(node.Intensities!.Value!);
-                if (isNotLeaf) subnodeGuids = subnodes.Map(x => x.HasValue && x.Value.hasValue ? x.Value.value!.Id : Guid.Empty);
+                if (isNotLeaf) subnodeGuids = subnodes.Map(x => x != null ? x.Id : Guid.Empty);
             }
 
 
diff --git a/src/Aardvark.Geometry.PointSet/Octrees/PointSet.cs b/src/Aardvark.Geometry.PointSet/Octrees/PointSet.cs
index cb29f2c9..8334ca36 100644
--- a/src/Aardvark.Geometry.PointSet/Octrees/PointSet.cs
+++ b/src/Aardvark.Geometry.PointSet/Octrees/PointSet.cs
@@ -15,6 +15,7 @@ You should have received a copy of the GNU Affero General Public License
 using Aardvark.Data.Points;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text.Json;
 using System.Text.Json.Nodes;
@@ -95,8 +96,8 @@ public PointSet(Storage storage, string pointSetId, Guid rootCellId, int splitLi
             Id = pointSetId ?? throw new ArgumentNullException(nameof(pointSetId));
             SplitLimit = splitLimit;
 
-            Root = new PersistentRef<IPointCloudNode>(rootCellId.ToString(), storage.GetPointCloudNode!,
-                k => { var (a, b) = storage.TryGetPointCloudNode(k); return (a, b); }
+            Root = new PersistentRef<IPointCloudNode>(rootCellId.ToString(), storage.GetPointCloudNode,
+                storage.TryGetPointCloudNode
                 );
         }
 
@@ -111,7 +112,7 @@ public PointSet(Storage storage, string key, IPointCloudNode root, int splitLimi
             Id = key ?? throw new ArgumentNullException(nameof(key));
             SplitLimit = splitLimit;
 
-            Root = new PersistentRef<IPointCloudNode>(root.Id.ToString(), storage.GetPointCloudNode!, storage.TryGetPointCloudNode);
+            Root = new PersistentRef<IPointCloudNode>(root.Id.ToString(), storage.GetPointCloudNode, storage.TryGetPointCloudNode);
         }
 
         /// <summary>
@@ -123,7 +124,7 @@ public PointSet(Storage storage, string key)
             Id = key ?? throw new ArgumentNullException(nameof(key));
             SplitLimit = 0;
 
-            Root = new(id: "", _ => PointSetNode.Empty, _ => (true, PointSetNode.Empty));
+            Root = new(id: Guid.Empty, PointSetNode.Empty);
         }
 
         #endregion
@@ -156,8 +157,8 @@ public PointSet(Storage storage, string key)
         public JsonNode ToJson() => JsonSerializer.SerializeToNode(new
         {
             Id,
-            RootCellId = Root.Id,
-            OctreeId = Root.Id, // backwards compatibility
+            OctreeId = Root.Id,
+            RootCellId = Root.Id, // backwards compatibility
             SplitLimit,
             PartIndexRange
         })!;
@@ -168,18 +169,22 @@ public static PointSet Parse(JsonNode json, Storage storage)
         {
             var o = json.AsObject() ?? throw new Exception($"Expected JSON object, but found {json}.");
 
+            // id
+            var id = (string?)o["Id"] ?? throw new Exception("Missing id. Error 71730558-699e-4128-b0f2-130fd04672e9.");
+
+
             var octreeId = (string?)o["OctreeId"] ?? (string?)o["RootCellId"];
+            if (octreeId == "" || octreeId == Guid.Empty.ToString()) octreeId = null;
+
             var octreeRef = octreeId != null
-                ? new PersistentRef<IPointCloudNode>(octreeId, storage.GetPointCloudNode!, storage.TryGetPointCloudNode)
+                ? new PersistentRef<IPointCloudNode>(octreeId, storage.GetPointCloudNode, storage.TryGetPointCloudNode)
                 : null 
                 ;
+            var octree = octreeRef?.Value;
 
             // backwards compatibility: if split limit is not set, guess as number of points in root cell
             var splitLimit = o.TryGetPropertyValue("SplitLimit", out var x) ? (int)x! : 8192;
 
-            // id
-            var id = (string?)o["Id"] ?? throw new Exception("Missing id. Error 71730558-699e-4128-b0f2-130fd04672e9.");
-
             // part index range (JsonArray)
             var partIndexRangeArray = (JsonArray?)o["PartIndexRange"];
             var partIndexRange = partIndexRangeArray != null
@@ -187,8 +192,6 @@ public static PointSet Parse(JsonNode json, Storage storage)
                 : Range1i.Invalid
                 ;
 
-            //
-            var octree = octreeRef?.Value;
             return new PointSet(storage, id, octree ?? PointSetNode.Empty, splitLimit).WithPartIndexRange(partIndexRange);
         }
 
diff --git a/src/Aardvark.Geometry.PointSet/Octrees/PointSetNode.cs b/src/Aardvark.Geometry.PointSet/Octrees/PointSetNode.cs
index 22d0e58c..f56951da 100644
--- a/src/Aardvark.Geometry.PointSet/Octrees/PointSetNode.cs
+++ b/src/Aardvark.Geometry.PointSet/Octrees/PointSetNode.cs
@@ -162,26 +162,26 @@ public PointSetNode(
             var isId = IntensitiesId;
             var ksId = ClassificationsId;
 
-            if (psId != null) PersistentRefs[Durable.Octree.PositionsLocal3fReference] = new PersistentRef<V3f[]>(psId.Value, storage.GetV3fArray!, storage.TryGetV3fArray);
-            if (csId != null) PersistentRefs[Durable.Octree.Colors4bReference] = new PersistentRef<C4b[]>(csId.Value, storage.GetC4bArray!, storage.TryGetC4bArray);
+            if (psId != null) PersistentRefs[Durable.Octree.PositionsLocal3fReference] = new PersistentRef<V3f[]>(psId.Value, storage.GetV3fArray, storage.TryGetV3fArrayFromCache);
+            if (csId != null) PersistentRefs[Durable.Octree.Colors4bReference] = new PersistentRef<C4b[]>(csId.Value, storage.GetC4bArray, storage.TryGetC4bArrayFromCache);
             if (kdId != null)
             {
                 if (isObsoleteFormat)
                 {
                     PersistentRefs[Durable.Octree.PointRkdTreeFDataReference] =
-                        new PersistentRef<PointRkdTreeF<V3f[], V3f>>(kdId.Value, LoadKdTreeObsolete, TryLoadKdTreeObsolete)
+                        new PersistentRef<PointRkdTreeF<V3f[], V3f>>(kdId.Value, LoadKdTreeObsolete, TryLoadKdTreeObsoleteOut)
                         ;
                 }
                 else
                 {
                     PersistentRefs[Durable.Octree.PointRkdTreeFDataReference] =
-                        new PersistentRef<PointRkdTreeF<V3f[], V3f>>(kdId.Value, LoadKdTree, TryLoadKdTree)
+                        new PersistentRef<PointRkdTreeF<V3f[], V3f>>(kdId.Value, LoadKdTree, TryLoadKdTreeOut)
                         ;
                 }
             }
-            if (nsId != null) PersistentRefs[Durable.Octree.Normals3fReference] = new PersistentRef<V3f[]>(nsId.Value, storage.GetV3fArray!, storage.TryGetV3fArray);
-            if (isId != null) PersistentRefs[Durable.Octree.Intensities1iReference] = new PersistentRef<int[]>(isId.Value, storage.GetIntArray!, storage.TryGetIntArray);
-            if (ksId != null) PersistentRefs[Durable.Octree.Classifications1bReference] = new PersistentRef<byte[]>(ksId.Value, storage.GetByteArray!, storage.TryGetByteArray);
+            if (nsId != null) PersistentRefs[Durable.Octree.Normals3fReference] = new PersistentRef<V3f[]>(nsId.Value, storage.GetV3fArray, storage.TryGetV3fArrayFromCache);
+            if (isId != null) PersistentRefs[Durable.Octree.Intensities1iReference] = new PersistentRef<int[]>(isId.Value, storage.GetIntArray, storage.TryGetIntArrayFromCache);
+            if (ksId != null) PersistentRefs[Durable.Octree.Classifications1bReference] = new PersistentRef<byte[]>(ksId.Value, storage.GetByteArray, storage.TryGetByteArrayFromCache);
 
 #endregion
 
@@ -323,7 +323,7 @@ public PointSetNode(
                 kdId = ComputeAndStoreKdTree(Storage, Positions.Value);
                 Data = Data.Add(Durable.Octree.PointRkdTreeFDataReference, kdId);
                 PersistentRefs[Durable.Octree.PointRkdTreeFDataReference] =
-                    new PersistentRef<PointRkdTreeF<V3f[], V3f>>(kdId.Value, LoadKdTree, TryLoadKdTree)
+                    new PersistentRef<PointRkdTreeF<V3f[], V3f>>(kdId.Value, LoadKdTree, TryLoadKdTreeOut)
                     ;
 #else
                 //Debugger.Break();
@@ -403,20 +403,6 @@ PointRkdTreeF<V3f[], V3f> LoadKdTree(string key)
                     );
             }
 
-            (bool, PointRkdTreeF<V3f[], V3f>?) TryLoadKdTree(string key)
-            {
-                var (ok, value) = Storage.TryGetPointRkdTreeFData(key);
-                if (ok == false) return (false, default);
-                var ps = Positions.Value!;
-                return (true, new PointRkdTreeF<V3f[], V3f>(
-                    3, ps.Length, ps,
-                    (xs, i) => xs[(int)i], (v, i) => (float)v[i],
-                    (a, b) => Vec.Distance(a, b), (i, a, b) => b - a,
-                    (a, b, c) => Vec.DistanceToLine(a, b, c), Fun.Lerp, 1e-6f,
-                    value
-                    ));
-            }
-
             PointRkdTreeF<V3f[], V3f> LoadKdTreeObsolete(string key)
             {
                 var value = Storage.GetPointRkdTreeFDataFromD(key);
@@ -430,18 +416,76 @@ PointRkdTreeF<V3f[], V3f> LoadKdTreeObsolete(string key)
                     );
             }
 
-            (bool, PointRkdTreeF<V3f[], V3f>?) TryLoadKdTreeObsolete(string key)
+            //(bool, PointRkdTreeF<V3f[], V3f>?) TryLoadKdTree(string key)
+            //{
+            //    var (ok, value) = Storage.TryGetPointRkdTreeFData(key);
+            //    if (ok == false) return (false, default);
+            //    var ps = Positions.Value!;
+            //    return (true, new PointRkdTreeF<V3f[], V3f>(
+            //        3, ps.Length, ps,
+            //        (xs, i) => xs[(int)i], (v, i) => (float)v[i],
+            //        (a, b) => Vec.Distance(a, b), (i, a, b) => b - a,
+            //        (a, b, c) => Vec.DistanceToLine(a, b, c), Fun.Lerp, 1e-6f,
+            //        value
+            //        ));
+            //}
+
+            //(bool, PointRkdTreeF<V3f[], V3f>?) TryLoadKdTreeObsolete(string key)
+            //{
+            //    var (ok, value) = Storage.TryGetPointRkdTreeFDataFromD(key);
+            //    if (ok == false) return (false, default);
+            //    var ps = Positions.Value!;
+            //    return (true, new PointRkdTreeF<V3f[], V3f>(
+            //        3, ps.Length, ps,
+            //        (xs, i) => xs[(int)i], (v, i) => (float)v[i],
+            //        (a, b) => Vec.Distance(a, b), (i, a, b) => b - a,
+            //        (a, b, c) => Vec.DistanceToLine(a, b, c), Fun.Lerp, 1e-6f,
+            //        value
+            //        ));
+            //}
+
+            bool TryLoadKdTreeOut(string key, [NotNullWhen(true)] out PointRkdTreeF<V3f[], V3f>? result)
+            {
+                var (ok, value) = Storage.TryGetPointRkdTreeFData(key);
+                if (ok == false)
+                {
+                    result = default;
+                    return false;
+                }
+                else
+                {
+                    var ps = Positions.Value!;
+                    result = new PointRkdTreeF<V3f[], V3f>(
+                        3, ps.Length, ps,
+                        (xs, i) => xs[(int)i], (v, i) => (float)v[i],
+                        (a, b) => Vec.Distance(a, b), (i, a, b) => b - a,
+                        (a, b, c) => Vec.DistanceToLine(a, b, c), Fun.Lerp, 1e-6f,
+                        value
+                        );
+                    return true;
+                }
+            }
+
+            bool TryLoadKdTreeObsoleteOut(string key, [NotNullWhen(true)] out PointRkdTreeF<V3f[], V3f>? result)
             {
                 var (ok, value) = Storage.TryGetPointRkdTreeFDataFromD(key);
-                if (ok == false) return (false, default);
-                var ps = Positions.Value!;
-                return (true, new PointRkdTreeF<V3f[], V3f>(
-                    3, ps.Length, ps,
-                    (xs, i) => xs[(int)i], (v, i) => (float)v[i],
-                    (a, b) => Vec.Distance(a, b), (i, a, b) => b - a,
-                    (a, b, c) => Vec.DistanceToLine(a, b, c), Fun.Lerp, 1e-6f,
-                    value
-                    ));
+                if (ok == false)
+                {
+                    result = default;
+                    return false;
+                }
+                else
+                {
+                    var ps = Positions.Value!;
+                    result = new PointRkdTreeF<V3f[], V3f>(
+                        3, ps.Length, ps,
+                        (xs, i) => xs[(int)i], (v, i) => (float)v[i],
+                        (a, b) => Vec.Distance(a, b), (i, a, b) => b - a,
+                        (a, b, c) => Vec.DistanceToLine(a, b, c), Fun.Lerp, 1e-6f,
+                        value
+                        );
+                    return true;
+                }
             }
         }
 
@@ -571,13 +615,13 @@ public PersistentRef<V3f[]> Positions
                     else
                     {
                         var ps = Array.Empty<V3f>();
-                        return new PersistentRef<V3f[]>(Guid.Empty, _ => ps, _ => (true, ps));
+                        return new PersistentRef<V3f[]>(Guid.Empty, ps);
                     }
                 }
                 else if (Data.TryGetValue(Durable.Octree.PositionsLocal3f, out o))
                 {
                     var ps = (V3f[])o;
-                    return new PersistentRef<V3f[]>(Guid.Empty, _ => ps, _ => (true, ps));
+                    return new PersistentRef<V3f[]>(Guid.Empty, ps);
                 }
                 else if (Data.TryGetValue(Durable.Octree.PositionsLocal3b, out o))
                 {
@@ -588,7 +632,7 @@ public PersistentRef<V3f[]> Positions
                     var ps = new V3f[pCount];
                     for (int i = 0, j = 0; i < pCount; i++)
                         ps[i] = new V3f(qs[j++] * step - hsize, qs[j++] * step - hsize, qs[j++] * step - hsize);
-                    return new PersistentRef<V3f[]>(Guid.Empty, _ => ps, _ => (true, ps));
+                    return new PersistentRef<V3f[]>(Guid.Empty, ps);
                 }
                 else if (Data.TryGetValue(Durable.Octree.PositionsLocal3us, out o))
                 {
@@ -599,7 +643,7 @@ public PersistentRef<V3f[]> Positions
                     var ps = new V3f[pCount];
                     for (int i = 0, j = 0; i < pCount; i++)
                         ps[i] = new V3f(qs[j++] * step - hsize, qs[j++] * step - hsize, qs[j++] * step - hsize);
-                    return new PersistentRef<V3f[]>(Guid.Empty, _ => ps, _ => (true, ps));
+                    return new PersistentRef<V3f[]>(Guid.Empty, ps);
                 }
                 else if (Data.TryGetValue(Durable.Octree.PositionsLocal3ui, out o))
                 {
@@ -610,7 +654,7 @@ public PersistentRef<V3f[]> Positions
                     var ps = new V3f[pCount];
                     for (int i = 0, j = 0; i < pCount; i++)
                         ps[i] = new V3f(qs[j++] * step - hsize, qs[j++] * step - hsize, qs[j++] * step - hsize);
-                    return new PersistentRef<V3f[]>(Guid.Empty, _ => ps, _ => (true, ps));
+                    return new PersistentRef<V3f[]>(Guid.Empty, ps);
                 }
                 else if (Data.TryGetValue(Durable.Octree.PositionsLocal3ul, out o))
                 {
@@ -621,11 +665,10 @@ public PersistentRef<V3f[]> Positions
                     var ps = new V3f[pCount];
                     for (int i = 0, j = 0; i < pCount; i++)
                         ps[i] = new V3f(qs[j++] * step - hsize, qs[j++] * step - hsize, qs[j++] * step - hsize);
-                    return new PersistentRef<V3f[]>(Guid.Empty, _ => ps, _ => (true, ps));
+                    return new PersistentRef<V3f[]>(Guid.Empty, ps);
                 }
                 else
                     return null!;
-                    //return new(id: "", _ => Array.Empty<V3f>(), _ => (true, Array.Empty<V3f>()));
             }
         }
 
@@ -710,20 +753,20 @@ public PersistentRef<C4b[]>? Colors
                 else if (Data.TryGetValue(Durable.Octree.Colors4b, out o))
                 {
                     var xs = (C4b[])o;
-                    return new PersistentRef<C4b[]>(Guid.Empty, _ => xs, _ => (true, xs));
+                    return new PersistentRef<C4b[]>(Guid.Empty, xs);
                 }
                 else if (PersistentRefs.TryGetValue(Durable.Octree.Colors3bReference, out o) && ((PersistentRef<C3b[]>)o).Id != GuidEmptyString)
                 {
                     // convert on the fly ...
                     var pref = (PersistentRef<C3b[]>)o;
                     var xs = pref.Value.Map(c => new C4b(c));
-                    return new PersistentRef<C4b[]>(Guid.Empty, _ => xs, _ => (true, xs));
+                    return new PersistentRef<C4b[]>(Guid.Empty, xs);
                 }
                 else if (Data.TryGetValue(Durable.Octree.Colors3b, out o))
                 {
                     // convert on the fly
                     var xs = ((C3b[])o).Map(c => new C4b(c));
-                    return new PersistentRef<C4b[]>(Guid.Empty, _ => xs, _ => (true, xs));
+                    return new PersistentRef<C4b[]>(Guid.Empty, xs);
                 }
                 else
                 {
@@ -762,7 +805,7 @@ public PersistentRef<V3f[]>? Normals
                 else if (Data.TryGetValue(Durable.Octree.Normals3f, out o))
                 {
                     var xs = (V3f[])o;
-                    return new PersistentRef<V3f[]>(Guid.Empty, _ => xs, _ => (true, xs));
+                    return new PersistentRef<V3f[]>(Guid.Empty, xs);
                 }
                 else
                 {
@@ -801,7 +844,7 @@ public PersistentRef<int[]>? Intensities
                 else if (Data.TryGetValue(Durable.Octree.Intensities1i, out o))
                 {
                     var xs = (int[])o;
-                    return new PersistentRef<int[]>(Guid.Empty, _ => xs, _ => (true, xs));
+                    return new PersistentRef<int[]>(Guid.Empty, xs);
                 }
                 else
                 {
@@ -840,7 +883,7 @@ public PersistentRef<byte[]>? Classifications
                 else if (Data.TryGetValue(Durable.Octree.Classifications1b, out o))
                 {
                     var xs = (byte[])o;
-                    return new PersistentRef<byte[]>(Guid.Empty, _ => xs, _ => (true, xs));
+                    return new PersistentRef<byte[]>(Guid.Empty, xs);
                 }
                 else
                 {
diff --git a/src/Aardvark.Geometry.PointSet/Utils/PersistentRef.cs b/src/Aardvark.Geometry.PointSet/Utils/PersistentRef.cs
index 4858b420..77374c71 100644
--- a/src/Aardvark.Geometry.PointSet/Utils/PersistentRef.cs
+++ b/src/Aardvark.Geometry.PointSet/Utils/PersistentRef.cs
@@ -15,54 +15,67 @@ You should have received a copy of the GNU Affero General Public License
 using System;
 using System.Diagnostics.CodeAnalysis;
 
-namespace Aardvark.Geometry.Points
+namespace Aardvark.Geometry.Points;
+
+
+/// <summary>
+/// </summary>
+public class PersistentRef<T> 
+    where T : notnull
 {
+    private readonly Func<string, T> f_get;
+    private readonly TryGetFunc f_tryGetFromCache;
+
+    public delegate bool TryGetFunc(string key, [NotNullWhen(true)] out T? result);
 
     /// <summary>
     /// </summary>
-    public class PersistentRef<T> 
-        where T : notnull
+    public PersistentRef(Guid id, Func<string, T> get, TryGetFunc tryGetFromCache)
+        : this(id.ToString(), get, tryGetFromCache)
     {
-        private readonly Func<string, T?> f_get;
-        private readonly Func<string, (bool, T?)> f_tryGet;
+    }
 
-        /// <summary>
-        /// </summary>
-        public PersistentRef(Guid id, Func<string, T> get, Func<string, (bool, T?)> tryGet)
-            : this(id.ToString(), get, tryGet)
-        {
-        }
+    /// <summary>
+    /// </summary>
+    public PersistentRef(string id, Func<string, T> get, TryGetFunc tryGetFromCache)
+    {
+        Id = id;
+        f_get = get ?? throw new ArgumentNullException(nameof(get));
+        f_tryGetFromCache = tryGetFromCache ?? throw new ArgumentNullException(nameof(tryGetFromCache));
+    }
 
-        /// <summary>
-        /// </summary>
-        public PersistentRef(string id, Func<string, T?> get, Func<string, (bool, T?)> tryGet)
-        {
-            Id = id; //?? throw new ArgumentNullException(nameof(id));
-            f_get = get ?? throw new ArgumentNullException(nameof(get));
-            f_tryGet = tryGet ?? throw new ArgumentNullException(nameof(tryGet));
-        }
-        
-        /// <summary>
-        /// </summary>
-        public string Id { get; }
-        
-        /// <summary>
-        /// </summary>
-        public bool TryGetValue([NotNullWhen(true)]out T? value)
+    /// <summary>
+    /// </summary>
+    public PersistentRef(Guid id, T valueInMemory)
+        : this(id.ToString(), valueInMemory)
+    {
+    }
+
+    /// <summary>
+    /// </summary>
+    public PersistentRef(string id, T valueInMemory)
+    {
+        Id = id;
+        f_get = _ => valueInMemory;
+        bool tryGetFromCache(string key, [NotNullWhen(true)] out T? result)
         {
-            bool isSome = false;
-            T? x = default;
-            (isSome, x) = f_tryGet(Id);
-            value = x;
-            return isSome;
+            result = valueInMemory;
+            return true;
         }
+        f_tryGetFromCache = tryGetFromCache;
+    }
+
+    /// <summary>
+    /// </summary>
+    public string Id { get; }
+    
+    /// <summary>
+    /// </summary>
+    public T Value => f_get(Id);
 
-        /// <summary>
-        /// </summary>
-        public (bool hasValue, T? value) TryGetValue() => f_tryGet(Id);
+    /// <summary>
+    /// </summary>
+    public bool TryGetFromCache([NotNullWhen(true)] out T? value)
+        => f_tryGetFromCache(Id, out value);
 
-        /// <summary>
-        /// </summary>
-        public T? Value => f_get(Id);
-    }
 }
diff --git a/src/Aardvark.Geometry.PointSet/Utils/StorageExtensions.cs b/src/Aardvark.Geometry.PointSet/Utils/StorageExtensions.cs
index b69c4307..c4ea6741 100644
--- a/src/Aardvark.Geometry.PointSet/Utils/StorageExtensions.cs
+++ b/src/Aardvark.Geometry.PointSet/Utils/StorageExtensions.cs
@@ -226,6 +226,25 @@ public static PointRkdTreeFData BufferToPointRkdTreeFData(byte[] buffer)
     /// </summary>
     public static class StorageExtensions
     {
+        #region Generic
+
+        /// <summary></summary>
+        public static bool TryGetFromCache<T>(this Storage storage, string key, [NotNullWhen(true)] out T? result)
+        {
+            if (storage.HasCache && storage.Cache.TryGetValue(key, out object o))
+            {
+                result = (T)o;
+                return true;
+            }
+            else
+            {
+                result = default;
+                return false;
+            }
+        }
+
+        #endregion
+
         #region Stores
 
         /// <summary></summary>
@@ -306,6 +325,8 @@ public static (bool, byte[]?) TryGetByteArray(this Storage storage, string key)
             return (buffer != null, buffer);
         }
 
+        public static bool TryGetByteArrayFromCache(this Storage storage, string key, [NotNullWhen(true)] out byte[]? result) => TryGetFromCache(storage, key, out result);
+
         /// <summary>
         /// Return ungzipped buffer, or original buffer if it is not gzipped.
         /// </summary>
@@ -410,17 +431,7 @@ public static void Add(this Storage storage, string key, IList<V3f> data)
         }
 
         /// <summary></summary>
-        public static (bool, V3f[]?) TryGetV3fArray(this Storage storage, string key)
-        {
-            if (storage.HasCache && storage.Cache.TryGetValue(key, out object o))
-            {
-                return (true, (V3f[])o);
-            }
-            else
-            {
-                return (false, default);
-            }
-        }
+        public static bool TryGetV3fArrayFromCache(this Storage storage, string key, [NotNullWhen(true)] out V3f[]? result) => TryGetFromCache(storage, key, out result);
 
         #endregion
 
@@ -461,6 +472,8 @@ public static (bool, int[]?) TryGetIntArray(this Storage storage, string key)
             }
         }
 
+        public static bool TryGetIntArrayFromCache(this Storage storage, string key, [NotNullWhen(true)] out int[]? result) => TryGetFromCache(storage, key, out result);
+
         #endregion
 
         #region C4b[]
@@ -500,6 +513,8 @@ public static (bool, C4b[]?) TryGetC4bArray(this Storage storage, string key)
             }
         }
 
+        public static bool TryGetC4bArrayFromCache(this Storage storage, string key, [NotNullWhen(true)] out C4b[]? result) => TryGetFromCache(storage, key, out result);
+
         #endregion
 
         #region PointRkdTreeDData
@@ -547,6 +562,8 @@ public static PointRkdTreeD<V3f[], V3f> GetKdTree(this Storage storage, string k
                 storage.GetPointRkdTreeDData(key)
                 );
 
+        public static bool TryGetPointRkdTreeDDataFromCache(this Storage storage, string key, [NotNullWhen(true)] out C4b[]? result) => TryGetFromCache(storage, key, out result);
+
         #endregion
 
         #region PointRkdTreeFData
@@ -602,6 +619,8 @@ public static (bool, PointRkdTreeFData?) TryGetPointRkdTreeFData(this Storage st
             }
         }
 
+        public static bool TryGetPointRkdTreeFDataFromCache(this Storage storage, string key, [NotNullWhen(true)] out C4b[]? result) => TryGetFromCache(storage, key, out result);
+
         /// <summary></summary>
         public static (bool, PointRkdTreeFData?) TryGetPointRkdTreeFDataFromD(this Storage storage, string key)
         {
@@ -615,30 +634,7 @@ public static (bool, PointRkdTreeFData?) TryGetPointRkdTreeFDataFromD(this Stora
             }
         }
 
-        ///// <summary>
-        ///// </summary>
-        //public static PointRkdTreeF<V3f[], V3f> GetKdTreeF(this Storage storage, string key, V3f[] positions)
-        //    => new PointRkdTreeF<V3f[], V3f>(
-        //        3, positions.Length, positions,
-        //        (xs, i) => xs[(int)i], (v, i) => (float)v[i],
-        //        (a, b) => V3f.Distance(a, b), (i, a, b) => b - a,
-        //        (a, b, c) => VecFun.DistanceToLine(a, b, c), VecFun.Lerp, 1e-6f,
-        //        storage.GetPointRkdTreeFData(key)
-        //        );
-
-        ///// <summary>
-        ///// </summary>
-        //public static (bool, PointRkdTreeF<V3f[], V3f>) TryGetKdTreeF(this Storage storage, string key, V3f[] positions)
-        //{
-        //    if (storage.HasCache && storage.Cache.TryGetValue(key, out object o))
-        //    {
-        //        return (true, (PointRkdTreeF<V3f[], V3f>)o);
-        //    }
-        //    else
-        //    {
-        //        return (false, default);
-        //    }
-        //}
+        public static bool TryGetPointRkdTreeFDataFromDFromCache(this Storage storage, string key, [NotNullWhen(true)] out C4b[]? result) => TryGetFromCache(storage, key, out result);
 
         #endregion
 
@@ -703,26 +699,30 @@ public static void Add(this Storage storage, string key, IPointCloudNode data)
             });
         }
 
-        /// <summary></summary>
-        public static IPointCloudNode? GetPointCloudNode(this Storage storage, Guid key)
+        /// <summary>
+        /// </summary>
+        public static IPointCloudNode GetPointCloudNode(this Storage storage, Guid key)
             => GetPointCloudNode(storage, key.ToString());
 
-        /// <summary></summary>
-        public static IPointCloudNode? GetPointCloudNode(this Storage storage, string key)
+        /// <summary>
+        /// </summary>
+        public static IPointCloudNode GetPointCloudNode(this Storage storage, string key)
         {
-            if (key == null) return null;
-
             if (storage.HasCache && storage.Cache.TryGetValue(key, out object o))
             {
-                //if (o == null) return null;
                 if (o is not IPointCloudNode r) throw new InvalidOperationException(
-                    $"Invariant d1cb769c-36b6-4374-8248-b8c1ca31d495. [GetPointCloudNode] Store key {key} is not IPointCloudNode."
+                    $"Invariant d1cb769c-36b6-4374-8248-b8c1ca31d495. " +
+                    $"[GetPointCloudNode] Store key {key} is not IPointCloudNode. " +
+                    $"Error 7aebf7f1-3783-42fb-b405-47384e08f716."
                     );
                 return r;
             }
 
             var buffer = storage.f_get(key);
-            if (buffer == null) return null;
+            if (buffer == null) throw new Exception(
+                $"PointCloudNode not found (id={key}). " +
+                $"Error b2ef55c1-1470-465d-80ea-034464c53638."
+                );
 
             try
             {
@@ -802,7 +802,34 @@ byte[] UnGzipBuffer(byte[] buffer)
             }
         }
 
-        /// <summary></summary>
+        /// <summary>
+        /// </summary>
+        public static bool TryGetPointCloudNode(this Storage storage, string key, [NotNullWhen(true)]out IPointCloudNode? result)
+        {
+            if (storage.HasCache && storage.Cache.TryGetValue(key, out object o))
+            {
+                result = (PointSetNode)o;
+                return true;
+            }
+            else
+            {
+                try
+                {
+                    result = storage.GetPointCloudNode(key);
+                    return true;
+                }
+                catch
+                {
+                    result = null;
+                    return false;
+                }
+            }
+        }
+
+        /// <summary>
+        /// </summary>
+
+        [Obsolete("Use TryGetPointCloudNode with out parameter instead.")]
         public static (bool, IPointCloudNode?) TryGetPointCloudNode(this Storage storage, string key)
         {
             if (storage.HasCache && storage.Cache.TryGetValue(key, out object o))
diff --git a/src/Aardvark.Geometry.PointSet/Views/FilteredNode.cs b/src/Aardvark.Geometry.PointSet/Views/FilteredNode.cs
index e9bec598..e3fc6cf5 100644
--- a/src/Aardvark.Geometry.PointSet/Views/FilteredNode.cs
+++ b/src/Aardvark.Geometry.PointSet/Views/FilteredNode.cs
@@ -254,7 +254,7 @@ public PersistentRef<IPointCloudNode>[]? Subnodes
                                 else if (n0 != null)
                                 {
                                     var n = new FilteredNode(id, false, n0, Filter);
-                                    m_subnodes_cache[i] = new PersistentRef<IPointCloudNode>(id.ToString(), _ => n, _ => (true, n));
+                                    m_subnodes_cache[i] = new PersistentRef<IPointCloudNode>(id, n);
                                 }
                             }
                             else
@@ -318,7 +318,7 @@ private void EnsurePositionsAndDerived()
             m_cache[Octree.BoundingBoxExactLocal.Id] = bboxLocal;
 
             var kd = psLocal.BuildKdTree();
-            var pRefKd = new PersistentRef<PointRkdTreeF<V3f[], V3f>>(Guid.NewGuid().ToString(), _ => kd, _ => (true, kd));
+            var pRefKd = new PersistentRef<PointRkdTreeF<V3f[], V3f>>(Guid.NewGuid(), kd);
             m_cache[Octree.PointRkdTreeFData.Id] = pRefKd;
 
             m_ensuredPositionsAndDerived = true;
@@ -531,7 +531,7 @@ public PersistentRef<PointRkdTreeF<V3f[], V3f>> KdTree
 
             var key = (Id + originalValue.Id).ToGuid().ToString();
             var xs = originalValue.Value.Where((_, i) => m_activePoints.Contains(i)).ToArray();
-            var result = new PersistentRef<T[]>(key, _ => xs, _ => (true, xs));
+            var result = new PersistentRef<T[]>(key, xs);
             m_cache[def.Id] = result;
             return result;
         }