diff --git a/assignment-client/src/scripts/EntityScriptServer.cpp b/assignment-client/src/scripts/EntityScriptServer.cpp
index f1a6c97831..514eb62380 100644
--- a/assignment-client/src/scripts/EntityScriptServer.cpp
+++ b/assignment-client/src/scripts/EntityScriptServer.cpp
@@ -301,10 +301,17 @@ void EntityScriptServer::run() {
 
     entityScriptingInterface->setEntityTree(_entityViewer.getTree());
 
-    DependencyManager::set<AssignmentParentFinder>(_entityViewer.getTree());
+    auto treePtr = _entityViewer.getTree();
+    DependencyManager::set<AssignmentParentFinder>(treePtr);
 
+    if (!_entitySimulation) {
+        SimpleEntitySimulationPointer simpleSimulation { new SimpleEntitySimulation() };
+        simpleSimulation->setEntityTree(treePtr);
+        treePtr->setSimulation(simpleSimulation);
+        _entitySimulation = simpleSimulation;
+    }
 
-    auto tree = _entityViewer.getTree().get();
+    auto tree = treePtr.get();
     connect(tree, &EntityTree::deletingEntity, this, &EntityScriptServer::deletingEntity, Qt::QueuedConnection);
     connect(tree, &EntityTree::addingEntity, this, &EntityScriptServer::addingEntity, Qt::QueuedConnection);
     connect(tree, &EntityTree::entityServerScriptChanging, this, &EntityScriptServer::entityServerScriptChanging, Qt::QueuedConnection);
@@ -451,6 +458,7 @@ void EntityScriptServer::resetEntitiesScriptEngine() {
 
     connect(newEngine.data(), &ScriptEngine::update, this, [this] {
         _entityViewer.queryOctree();
+        _entityViewer.getTree()->preUpdate();
         _entityViewer.getTree()->update();
     });
 
diff --git a/assignment-client/src/scripts/EntityScriptServer.h b/assignment-client/src/scripts/EntityScriptServer.h
index 944fee36a3..b795339174 100644
--- a/assignment-client/src/scripts/EntityScriptServer.h
+++ b/assignment-client/src/scripts/EntityScriptServer.h
@@ -21,6 +21,7 @@
 #include <EntityEditPacketSender.h>
 #include <plugins/CodecPlugin.h>
 #include <ScriptEngine.h>
+#include <SimpleEntitySimulation.h>
 #include <ThreadedAssignment.h>
 #include "../entities/EntityTreeHeadlessViewer.h"
 
@@ -75,6 +76,7 @@ private:
 
     static int _entitiesScriptEngineCount;
     ScriptEnginePointer _entitiesScriptEngine;
+    SimpleEntitySimulationPointer _entitySimulation;
     EntityEditPacketSender _entityEditSender;
     EntityTreeHeadlessViewer _entityViewer;