From a48ce78733ec1b286d72f8c61ba6e30ff3e39d09 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Thu, 26 Mar 2026 12:28:31 +0100
Subject: [PATCH] Fix crash when loading `CollisionData` before physics init

#3971
---
 Source/Engine/Content/Asset.cpp           | 34 +++++++++++++++++++++++
 Source/Engine/Content/Asset.h             |  4 +++
 Source/Engine/Content/Assets/Material.cpp | 13 ++-------
 Source/Engine/Physics/CollisionData.cpp   |  2 ++
 4 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/Source/Engine/Content/Asset.cpp b/Source/Engine/Content/Asset.cpp
index 7a35d3b28..a9b1a7fc9 100644
--- a/Source/Engine/Content/Asset.cpp
+++ b/Source/Engine/Content/Asset.cpp
@@ -8,6 +8,8 @@
 #include "Loading/Tasks/LoadAssetTask.h"
 #include "Engine/Core/Log.h"
 #include "Engine/Core/LogContext.h"
+#include "Engine/Graphics/GPUDevice.h"
+#include "Engine/Physics/Physics.h"
 #include "Engine/Profiler/ProfilerCPU.h"
 #include "Engine/Profiler/ProfilerMemory.h"
 #include "Engine/Scripting/ManagedCLR/MCore.h"
@@ -703,6 +705,38 @@ void Asset::onUnload_MainThread()
     OnUnloaded(this);
 }
 
+bool Asset::WaitForInitGraphics()
+{
+#define IS_GPU_NOT_READY() (GPUDevice::Instance == nullptr || GPUDevice::Instance->GetState() != GPUDevice::DeviceState::Ready)
+    if (!IsInMainThread() && IS_GPU_NOT_READY())
+    {
+        PROFILE_CPU();
+        ZoneColor(TracyWaitZoneColor);
+        int32 timeout = 1000;
+        while (IS_GPU_NOT_READY() && timeout-- > 0)
+            Platform::Sleep(1);
+        if (IS_GPU_NOT_READY())
+            return true;
+    }
+#undef IS_GPU_NOT_READY
+    return false;
+}
+
+bool Asset::WaitForInitPhysics()
+{
+    if (!IsInMainThread() && !Physics::DefaultScene)
+    {
+        PROFILE_CPU();
+        ZoneColor(TracyWaitZoneColor);
+        int32 timeout = 1000;
+        while (!Physics::DefaultScene && timeout-- > 0)
+            Platform::Sleep(1);
+        if (!Physics::DefaultScene)
+            return true;
+    }
+    return false;
+}
+
 #if USE_EDITOR
 
 bool Asset::OnCheckSave(const StringView& path) const
diff --git a/Source/Engine/Content/Asset.h b/Source/Engine/Content/Asset.h
index e6607e62c..a7913a5a5 100644
--- a/Source/Engine/Content/Asset.h
+++ b/Source/Engine/Content/Asset.h
@@ -285,6 +285,10 @@ protected:
     virtual void onRename(const StringView& newPath) = 0;
 #endif
 
+    // Utilities to ensure specific engine systems are initialized before loading asset (eg. assets can be loaded during engine startup).
+    static bool WaitForInitGraphics();
+    static bool WaitForInitPhysics();
+
 public:
     // [ManagedScriptingObject]
     String ToString() const override;
diff --git a/Source/Engine/Content/Assets/Material.cpp b/Source/Engine/Content/Assets/Material.cpp
index b4cf55d4d..e46060397 100644
--- a/Source/Engine/Content/Assets/Material.cpp
+++ b/Source/Engine/Content/Assets/Material.cpp
@@ -5,7 +5,6 @@
 #include "Engine/Core/Types/DataContainer.h"
 #include "Engine/Content/Upgraders/ShaderAssetUpgrader.h"
 #include "Engine/Content/Factories/BinaryAssetFactory.h"
-#include "Engine/Graphics/GPUDevice.h"
 #include "Engine/Graphics/RenderTools.h"
 #include "Engine/Graphics/Materials/MaterialShader.h"
 #include "Engine/Graphics/Shaders/Cache/ShaderCacheManager.h"
@@ -156,16 +155,8 @@ Asset::LoadResult Material::load()
     FlaxChunk* materialParamsChunk;
 
     // Wait for the GPU Device to be ready (eg. case when loading material before GPU init)
-#define IS_GPU_NOT_READY() (GPUDevice::Instance == nullptr || GPUDevice::Instance->GetState() != GPUDevice::DeviceState::Ready)
-    if (!IsInMainThread() && IS_GPU_NOT_READY())
-    {
-        int32 timeout = 1000;
-        while (IS_GPU_NOT_READY() && timeout-- > 0)
-            Platform::Sleep(1);
-        if (IS_GPU_NOT_READY())
-            return LoadResult::InvalidData;
-    }
-#undef IS_GPU_NOT_READY
+    if (WaitForInitGraphics())
+        return LoadResult::CannotLoadData;
 
     // If engine was compiled with shaders compiling service:
     // - Material should be changed in need to convert it to the newer version (via Visject Surface)
diff --git a/Source/Engine/Physics/CollisionData.cpp b/Source/Engine/Physics/CollisionData.cpp
index c65ea8a6b..94cef111e 100644
--- a/Source/Engine/Physics/CollisionData.cpp
+++ b/Source/Engine/Physics/CollisionData.cpp
@@ -257,6 +257,8 @@ Asset::LoadResult CollisionData::load()
 
 CollisionData::LoadResult CollisionData::load(const SerializedOptions* options, byte* dataPtr, int32 dataSize)
 {
+    if (WaitForInitPhysics())
+        return LoadResult::CannotLoadData;
     PROFILE_MEM(Physics);
 
     // Load options