diff --git a/Editor/ObjectWindow.cpp b/Editor/ObjectWindow.cpp
index 10732c20a..60b643645 100644
--- a/Editor/ObjectWindow.cpp
+++ b/Editor/ObjectWindow.cpp
@@ -710,7 +710,7 @@ void ObjectWindow::Create(EditorComponent* editor)
 			x->SetLightmapRenderRequest(true);
 		}
 
-		scene.InvalidateBVH();
+		scene.SetAccelerationStructureUpdateRequested(true);
 
 	});
 	AddWidget(&generateLightmapButton);
diff --git a/WickedEngine/RenderPath3D.cpp b/WickedEngine/RenderPath3D.cpp
index 84e9e5779..8092650e7 100644
--- a/WickedEngine/RenderPath3D.cpp
+++ b/WickedEngine/RenderPath3D.cpp
@@ -526,6 +526,13 @@ void RenderPath3D::Update(float dt)
 	if (getSceneUpdateEnabled())
 	{
 		scene->Update(dt * wiRenderer::GetGameSpeed());
+
+		if (wiRenderer::GetRaytracedShadowsEnabled() ||
+			getAO() == AO_RTAO ||
+			getRaytracedReflectionEnabled())
+		{
+			scene->SetAccelerationStructureUpdateRequested(true);
+		}
 	}
 
 	// Frustum culling for main camera:
@@ -596,15 +603,18 @@ void RenderPath3D::Render() const
 		RenderFrameSetUp(cmd);
 		});
 
-	// Acceleration structures:
-	//	async compute parallel with depth prepass
-	cmd = device->BeginCommandList(QUEUE_COMPUTE); 
-	device->WaitCommandList(cmd, cmd_prepareframe);
-	wiJobSystem::Execute(ctx, [this, cmd](wiJobArgs args) {
+	if (scene->IsAccelerationStructureUpdateRequested())
+	{
+		// Acceleration structures:
+		//	async compute parallel with depth prepass
+		cmd = device->BeginCommandList(QUEUE_COMPUTE);
+		device->WaitCommandList(cmd, cmd_prepareframe);
+		wiJobSystem::Execute(ctx, [this, cmd](wiJobArgs args) {
 
-		wiRenderer::UpdateRaytracingAccelerationStructures(*scene, cmd);
+			wiRenderer::UpdateRaytracingAccelerationStructures(*scene, cmd);
 
-		});
+			});
+	}
 
 	static const uint32_t drawscene_flags =
 		wiRenderer::DRAWSCENE_OPAQUE |
diff --git a/WickedEngine/RenderPath3D_PathTracing.cpp b/WickedEngine/RenderPath3D_PathTracing.cpp
index 761876b34..b2ab00d10 100644
--- a/WickedEngine/RenderPath3D_PathTracing.cpp
+++ b/WickedEngine/RenderPath3D_PathTracing.cpp
@@ -144,10 +144,8 @@ void RenderPath3D_PathTracing::Update(float dt)
 		resetProgress();
 	}
 
-	if (sam == 0)
-	{
-		scene->InvalidateBVH();
-	}
+	scene->SetAccelerationStructureUpdateRequested(sam == 0);
+	setSceneUpdateEnabled(sam == 0);
 
 	RenderPath3D::Update(dt);
 
@@ -255,7 +253,10 @@ void RenderPath3D_PathTracing::Render() const
 
 			wiRenderer::UpdateRenderData(visibility_main, frameCB, cmd);
 
-			wiRenderer::UpdateRaytracingAccelerationStructures(*scene, cmd);
+			if (scene->IsAccelerationStructureUpdateRequested())
+			{
+				wiRenderer::UpdateRaytracingAccelerationStructures(*scene, cmd);
+			}
 			});
 
 		// Main scene:
diff --git a/WickedEngine/wiRenderer.cpp b/WickedEngine/wiRenderer.cpp
index e7a6fd6fa..79deab487 100644
--- a/WickedEngine/wiRenderer.cpp
+++ b/WickedEngine/wiRenderer.cpp
@@ -3534,7 +3534,7 @@ void UpdatePerFrameData(
 
 	wiJobSystem::Wait(ctx);
 
-	if (!device->CheckCapability(GRAPHICSDEVICE_CAPABILITY_RAYTRACING_PIPELINE) && !device->CheckCapability(GRAPHICSDEVICE_CAPABILITY_RAYTRACING_INLINE) && scene.BVH_invalid)
+	if (!device->CheckCapability(GRAPHICSDEVICE_CAPABILITY_RAYTRACING_PIPELINE) && !device->CheckCapability(GRAPHICSDEVICE_CAPABILITY_RAYTRACING_INLINE) && scene.IsAccelerationStructureUpdateRequested())
 	{
 		scene.BVH.Update(scene);
 	}
@@ -4275,12 +4275,10 @@ void UpdateRaytracingAccelerationStructures(const Scene& scene, CommandList cmd)
 	}
 	else
 	{
-		if (scene.BVH_invalid)
-		{
-			scene.BVH_invalid = false;
-			scene.BVH.Build(scene, cmd);
-		}
+		scene.BVH.Build(scene, cmd);
 	}
+
+	scene.acceleration_structure_update_requested = false;
 }
 void OcclusionCulling_Render(const CameraComponent& camera_previous, const Visibility& vis, CommandList cmd)
 {
@@ -7800,6 +7798,8 @@ void RefreshLightmapAtlas(const Scene& scene, CommandList cmd)
 		for (uint32_t i = 0; i < scene.objects.GetCount(); ++i)
 		{
 			const ObjectComponent& object = scene.objects[i];
+			if (!object.lightmap.IsValid())
+				continue;
 
 			if (object.IsLightmapRenderRequested())
 			{
diff --git a/WickedEngine/wiScene.cpp b/WickedEngine/wiScene.cpp
index fd5cd19ff..a920be251 100644
--- a/WickedEngine/wiScene.cpp
+++ b/WickedEngine/wiScene.cpp
@@ -1569,7 +1569,7 @@ namespace wiScene
 
 		if (lightmap_refresh_needed.load())
 		{
-			InvalidateBVH();
+			SetAccelerationStructureUpdateRequested(true);
 		}
 		if (lightmap_repack_needed.load())
 		{
diff --git a/WickedEngine/wiScene.h b/WickedEngine/wiScene.h
index d2ec34b71..adb8550a7 100644
--- a/WickedEngine/wiScene.h
+++ b/WickedEngine/wiScene.h
@@ -1280,18 +1280,17 @@ namespace wiScene
 		};
 		uint32_t flags = EMPTY;
 
+
 		wiSpinLock locker;
 		AABB bounds;
 		std::vector<AABB> parallel_bounds;
 		WeatherComponent weather;
 		wiGraphics::RaytracingAccelerationStructure TLAS;
 		std::vector<uint8_t> TLAS_instances;
-
 		wiGPUBVH BVH; // this is for non-hardware accelerated raytracing
-		mutable bool BVH_invalid = false;
-		void InvalidateBVH() {
-			BVH_invalid = true;
-		}
+		mutable bool acceleration_structure_update_requested = false;
+		void SetAccelerationStructureUpdateRequested(bool value = true) { acceleration_structure_update_requested = value; }
+		bool IsAccelerationStructureUpdateRequested() const { return acceleration_structure_update_requested; }
 
 		// Occlusion query state:
 		wiGraphics::GPUQueryHeap queryHeap[arraysize(ObjectComponent::occlusionQueries)];
diff --git a/WickedEngine/wiVersion.cpp b/WickedEngine/wiVersion.cpp
index 3c5421c97..856eefaee 100644
--- a/WickedEngine/wiVersion.cpp
+++ b/WickedEngine/wiVersion.cpp
@@ -9,7 +9,7 @@ namespace wiVersion
 	// minor features, major updates, breaking compatibility changes
 	const int minor = 56;
 	// minor bug fixes, alterations, refactors, updates
-	const int revision = 45;
+	const int revision = 46;
 
 	const std::string version_string = std::to_string(major) + "." + std::to_string(minor) + "." + std::to_string(revision);