From 950289db9f93af31525a2cfb62cb60f47785b99f Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Sat, 3 Dec 2022 11:23:26 +0100
Subject: [PATCH] Fix crash when drawing scene in async and content streaming
 updates model residency

---
 Source/Engine/Level/Scene/SceneRendering.cpp | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/Source/Engine/Level/Scene/SceneRendering.cpp b/Source/Engine/Level/Scene/SceneRendering.cpp
index 07990cb79..55d3946e3 100644
--- a/Source/Engine/Level/Scene/SceneRendering.cpp
+++ b/Source/Engine/Level/Scene/SceneRendering.cpp
@@ -42,9 +42,21 @@ FORCE_INLINE bool FrustumsListCull(const BoundingSphere& bounds, const Array<Bou
 void SceneRendering::Draw(RenderContextBatch& renderContextBatch, DrawCategory category)
 {
     ScopeLock lock(Locker);
+    if (category == PreRender)
+    {
+        // Register scene
+        for (const auto& renderContext : renderContextBatch.Contexts)
+            renderContext.List->Scenes.Add(this);
+
+        // Add additional lock during scene rendering (prevents any Actors cache modifications on content streaming threads - eg. when model residency changes)
+        Locker.Lock();
+    }
+    else if (category == PostRender)
+    {
+        // Release additional lock
+        Locker.Unlock();
+    }
     auto& view = renderContextBatch.GetMainContext().View;
-    for (auto& renderContext : renderContextBatch.Contexts)
-        renderContext.List->Scenes.Add(this);
     auto& list = Actors[(int32)category];
     _drawListData = list.Get();
     _drawListSize = list.Count();