diff --git a/src/main/java/com/marginallyclever/ro3/apps/RO3Frame.java b/src/main/java/com/marginallyclever/ro3/apps/RO3Frame.java
index 70645709b..2ba01a81a 100644
--- a/src/main/java/com/marginallyclever/ro3/apps/RO3Frame.java
+++ b/src/main/java/com/marginallyclever/ro3/apps/RO3Frame.java
@@ -11,6 +11,7 @@
 import com.formdev.flatlaf.FlatLightLaf;
 import com.marginallyclever.communications.application.TextInterfaceToSessionLayer;
 import com.marginallyclever.ro3.RO3;
+import com.marginallyclever.ro3.Registry;
 import com.marginallyclever.ro3.UndoSystem;
 import com.marginallyclever.ro3.apps.about.AboutPanel;
 import com.marginallyclever.ro3.apps.actions.*;
@@ -277,7 +278,6 @@ private void createLayout() {
         detailView.add(nodeDetailView, BorderLayout.CENTER);
         Docking.dock(detailView, treeView, DockingRegion.SOUTH);
         windows.add(detailView);
-        nodeTreeView.addSelectionChangeListener(nodeDetailView);
 
         DockingPanel logView = new DockingPanel("5e565f83-9734-4281-9828-92cd711939df","Log");
         logView.add(logPanel, BorderLayout.CENTER);
diff --git a/src/main/java/com/marginallyclever/ro3/apps/nodedetailview/NodeDetailView.java b/src/main/java/com/marginallyclever/ro3/apps/nodedetailview/NodeDetailView.java
index d26f3b493..ccb97d3b7 100644
--- a/src/main/java/com/marginallyclever/ro3/apps/nodedetailview/NodeDetailView.java
+++ b/src/main/java/com/marginallyclever/ro3/apps/nodedetailview/NodeDetailView.java
@@ -1,5 +1,8 @@
 package com.marginallyclever.ro3.apps.nodedetailview;
 
+import com.marginallyclever.ro3.Registry;
+import com.marginallyclever.ro3.listwithevents.ItemAddedListener;
+import com.marginallyclever.ro3.listwithevents.ItemRemovedListener;
 import com.marginallyclever.ro3.node.Node;
 import com.marginallyclever.ro3.apps.nodetreeview.SelectionChangeListener;
 import org.slf4j.Logger;
@@ -13,7 +16,8 @@
 /**
  * {@link NodeDetailView} is a panel that displays the details of a class that implements {@link Node}.
  */
-public class NodeDetailView extends JPanel implements SelectionChangeListener {
+public class NodeDetailView extends JPanel
+        implements SelectionChangeListener, ItemAddedListener<Node>, ItemRemovedListener<Node> {
     private static final Logger logger = LoggerFactory.getLogger(NodeDetailView.class);
     private final JScrollPane scroll = new JScrollPane();
 
@@ -65,4 +69,28 @@ public void selectionChanged(List<Node> selectedNodes) {
         this.revalidate();
         this.repaint();
     }
+
+    @Override
+    public void addNotify() {
+        super.addNotify();
+        Registry.selection.addItemAddedListener(this);
+        Registry.selection.addItemRemovedListener(this);
+    }
+
+    @Override
+    public void removeNotify() {
+        super.removeNotify();
+        Registry.selection.removeItemAddedListener(this);
+        Registry.selection.removeItemRemovedListener(this);
+    }
+
+    @Override
+    public void itemAdded(Object source,Node item) {
+        selectionChanged(Registry.selection.getList());
+    }
+
+    @Override
+    public void itemRemoved(Object source,Node item) {
+        selectionChanged(Registry.selection.getList());
+    }
 }
diff --git a/src/main/java/com/marginallyclever/ro3/apps/nodetreeview/NodeTreeView.java b/src/main/java/com/marginallyclever/ro3/apps/nodetreeview/NodeTreeView.java
index 44bd31c5e..fcccfa25a 100644
--- a/src/main/java/com/marginallyclever/ro3/apps/nodetreeview/NodeTreeView.java
+++ b/src/main/java/com/marginallyclever/ro3/apps/nodetreeview/NodeTreeView.java
@@ -4,6 +4,8 @@
 import com.marginallyclever.ro3.SceneChangeListener;
 import com.marginallyclever.ro3.apps.actions.AddNode;
 import com.marginallyclever.ro3.apps.actions.RemoveNode;
+import com.marginallyclever.ro3.listwithevents.ItemAddedListener;
+import com.marginallyclever.ro3.listwithevents.ItemRemovedListener;
 import com.marginallyclever.ro3.node.Node;
 import com.marginallyclever.ro3.node.NodeAttachListener;
 import com.marginallyclever.ro3.node.NodeDetachListener;
@@ -13,6 +15,7 @@
 
 import javax.swing.*;
 import javax.swing.event.EventListenerList;
+import javax.swing.event.TreeSelectionEvent;
 import javax.swing.tree.*;
 import java.awt.*;
 import java.security.InvalidParameterException;
@@ -23,13 +26,16 @@
 /**
  * {@link NodeTreeView} is a panel that displays the node tree.
  */
-public class NodeTreeView extends JPanel implements NodeAttachListener, NodeDetachListener, NodeRenameListener, SceneChangeListener {
+public class NodeTreeView extends JPanel
+        implements NodeAttachListener, NodeDetachListener, NodeRenameListener,
+        SceneChangeListener, ItemAddedListener<Node>, ItemRemovedListener<Node> {
     private static final Logger logger = LoggerFactory.getLogger(NodeTreeView.class);
     private final JTree tree;
     private final NodeTreeBranch treeModel = new NodeTreeBranch(Registry.getScene());
     private final EventListenerList listenerList = new EventListenerList();
     private final JToolBar toolBar = new JToolBar();
     private final RemoveNode removeNode = new RemoveNode(this);
+    private boolean isExternalChange = false;
 
     public NodeTreeView() {
         super();
@@ -57,26 +63,31 @@ private void setupTree() {
         tree.setCellRenderer(cellRender);
         tree.setCellEditor(new NodeTreeBranchEditor(tree, cellRender));
         tree.setTransferHandler(new NodeTreeTransferHandler());
-        tree.addTreeSelectionListener((e) ->{
-            // single selection
-            TreePath path = e.getPath();
-            if(path==null) {
-                // no selection
-                removeNode.setEnabled(false);
-                fireSelectionChangeEvent(List.of());
-            } else {
-                NodeTreeBranch selectedNode = (NodeTreeBranch) path.getLastPathComponent();
-                // scene root cannot be deleted.
-                removeNode.setEnabled(selectedNode != treeModel.getRoot());
-                fireSelectionChangeEvent(List.of(selectedNode.getNode()));
-            }
-        });
+        tree.addTreeSelectionListener(this::changeSelection);
+    }
+
+    private void changeSelection(TreeSelectionEvent e) {
+        if(isExternalChange) return;
+
+        Registry.selection.removeAll();
+        removeNode.setEnabled(false);
+        // handle many selections
+        for(TreePath path : e.getPaths()) {
+            NodeTreeBranch selectedNode = (NodeTreeBranch) path.getLastPathComponent();
+            // scene root cannot be deleted.
+            removeNode.setEnabled(selectedNode != treeModel.getRoot());
+            Registry.selection.add(selectedNode.getNode());
+        }
     }
 
     @Override
     public void addNotify() {
         super.addNotify();
         Registry.addSceneChangeListener(this);
+        Registry.selection.addItemAddedListener(this);
+        Registry.selection.addItemRemovedListener(this);
+
+
         listenTo(Registry.getScene());
     }
 
@@ -91,6 +102,8 @@ public void removeNotify() {
         super.removeNotify();
         stopListeningTo(Registry.getScene());
         Registry.removeSceneChangeListener(this);
+        Registry.selection.removeItemAddedListener(this);
+        Registry.selection.removeItemRemovedListener(this);
     }
 
     private void stopListeningTo(Node node) {
@@ -220,7 +233,6 @@ public void beforeSceneChange(Node oldScene) {
         //logger.debug("beforeSceneChange");
         stopListeningTo(oldScene);
         tree.clearSelection();  // does not trigger selection change event?
-        fireSelectionChangeEvent(List.of());
         removeNode.setEnabled(false);
     }
 
@@ -271,4 +283,28 @@ public void removeSelectedNodes() {
             } // else root node, can't remove.
         }
     }
+
+    @Override
+    public void itemAdded(Object source,Node item) {
+        isExternalChange = true;
+        try {
+            var branch = findTreeNode(item);
+            if (branch == null) throw new InvalidParameterException("item not found in tree " + item.getAbsolutePath());
+            tree.addSelectionPath(new TreePath(branch.getPath()));
+        } finally {
+            isExternalChange = false;
+        }
+    }
+
+    @Override
+    public void itemRemoved(Object source,Node item) {
+        isExternalChange = true;
+        try {
+            var branch = findTreeNode(item);
+            if(branch==null) throw new InvalidParameterException("item not found in tree "+item.getAbsolutePath());
+            tree.removeSelectionPath(new TreePath(branch.getPath()));
+        } finally {
+            isExternalChange = false;
+        }
+    }
 }
diff --git a/src/main/java/com/marginallyclever/ro3/apps/render/Viewport.java b/src/main/java/com/marginallyclever/ro3/apps/render/Viewport.java
index f5037a81e..c4ec2e5f9 100644
--- a/src/main/java/com/marginallyclever/ro3/apps/render/Viewport.java
+++ b/src/main/java/com/marginallyclever/ro3/apps/render/Viewport.java
@@ -170,7 +170,7 @@ private void addRenderPassSelection() {
         button.setToolTipText("Select the render passes to use.");
 
         for(RenderPass renderPass : renderPasses.getList()) {
-            addRenderPass(renderPass);
+            addRenderPass(null,renderPass);
         }
     }
 
@@ -192,12 +192,12 @@ public void removeNotify() {
         renderPasses.removeItemRemovedListener(this::removeRenderPass);
     }
 
-    private void addRenderPass(RenderPass renderPass) {
+    private void addRenderPass(Object source,RenderPass renderPass) {
         addRenderPassInternal(renderPass);
         addGLEventListener(renderPass);
     }
 
-    private void removeRenderPass(RenderPass renderPass) {
+    private void removeRenderPass(Object source,RenderPass renderPass) {
         removeRenderPassInternal(renderPass);
         removeGLEventListener(renderPass);
     }
@@ -237,13 +237,13 @@ private void removeRenderPassInternal(RenderPass renderPass) {
         }
     }
 
-    private void addCamera(Camera camera) {
+    private void addCamera(Object source,Camera camera) {
         if(cameraListModel.getIndexOf(camera) == -1) {
             cameraListModel.addElement(camera);
         }
     }
 
-    private void removeCamera(Camera camera) {
+    private void removeCamera(Object source,Camera camera) {
         cameraListModel.removeElement(camera);
     }
 
diff --git a/src/main/java/com/marginallyclever/ro3/apps/render/renderpasses/DrawMeshes.java b/src/main/java/com/marginallyclever/ro3/apps/render/renderpasses/DrawMeshes.java
index 0033d3061..a1889caa2 100644
--- a/src/main/java/com/marginallyclever/ro3/apps/render/renderpasses/DrawMeshes.java
+++ b/src/main/java/com/marginallyclever/ro3/apps/render/renderpasses/DrawMeshes.java
@@ -281,7 +281,7 @@ private void drawAllMeshes(GL3 gl3, List<MeshInstance> meshes, Camera camera) {
     // https://learnopengl.com/Advanced-Lighting/Shadows/Shadow-Mapping
     private Matrix4d getLightSpaceMatrix() {
         // orthographic projection from the light's point of view
-        Matrix4d lightProjection = MatrixHelper.orthographicMatrix4d(-10,10,-10,10,1.0,100.0);
+        Matrix4d lightProjection = MatrixHelper.orthographicMatrix4d(-10,10,-10,10,1.0,75);
         // look at the scene from the light's point of view
         Matrix4d lightView = MatrixHelper.lookAt(fromLightUnit,  // from
                                                 new Vector3d(0,0,0),  // to
diff --git a/src/main/java/com/marginallyclever/ro3/listwithevents/ItemAddedListener.java b/src/main/java/com/marginallyclever/ro3/listwithevents/ItemAddedListener.java
index dfb52c78e..b27a34462 100644
--- a/src/main/java/com/marginallyclever/ro3/listwithevents/ItemAddedListener.java
+++ b/src/main/java/com/marginallyclever/ro3/listwithevents/ItemAddedListener.java
@@ -3,5 +3,5 @@
 import java.util.EventListener;
 
 public interface ItemAddedListener<T> extends EventListener {
-    void itemAdded(T item);
+    void itemAdded(Object source,T item);
 }
\ No newline at end of file
diff --git a/src/main/java/com/marginallyclever/ro3/listwithevents/ItemRemovedListener.java b/src/main/java/com/marginallyclever/ro3/listwithevents/ItemRemovedListener.java
index 2e7ce41d6..6209ef5fb 100644
--- a/src/main/java/com/marginallyclever/ro3/listwithevents/ItemRemovedListener.java
+++ b/src/main/java/com/marginallyclever/ro3/listwithevents/ItemRemovedListener.java
@@ -3,5 +3,5 @@
 import java.util.EventListener;
 
 public interface ItemRemovedListener<T> extends EventListener {
-    void itemRemoved(T item);
+    void itemRemoved(Object source,T item);
 }
\ No newline at end of file
diff --git a/src/main/java/com/marginallyclever/ro3/listwithevents/ListWithEvents.java b/src/main/java/com/marginallyclever/ro3/listwithevents/ListWithEvents.java
index 6cb6e6a0a..b4de8682b 100644
--- a/src/main/java/com/marginallyclever/ro3/listwithevents/ListWithEvents.java
+++ b/src/main/java/com/marginallyclever/ro3/listwithevents/ListWithEvents.java
@@ -2,7 +2,6 @@
 
 import javax.swing.event.EventListenerList;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 
 /**
@@ -41,13 +40,13 @@ public void removeItemRemovedListener(ItemRemovedListener<T> listener) {
 
     protected void fireItemAdded(T item) {
         for (ItemAddedListener<T> l : listenerList.getListeners(ItemAddedListener.class)) {
-            l.itemAdded(item);
+            l.itemAdded(this,item);
         }
     }
 
     protected void fireItemRemoved(T item) {
         for (ItemRemovedListener<T> l : listenerList.getListeners(ItemRemovedListener.class)) {
-            l.itemRemoved(item);
+            l.itemRemoved(this,item);
         }
     }
 
@@ -60,4 +59,8 @@ public void removeAll() {
             remove(list.get(0));
         }
     }
+
+    public int size() {
+        return list.size();
+    }
 }
\ No newline at end of file