Feature/instant controls

Source/Blend4Real/Private/Blend4Real.cpp

@@ -122,10 +122,23 @@ void FBlend4RealModule::OnBeginPIE(bool bIsSimulating)
 	{
 		bWasEnabledBeforePIE = false;
 	}
+
+	// Unregister the input processor entirely during PIE to prevent transient mode from
+	// activating and accessing invalid viewport state
+	if (BlenderInputHandler.IsValid())
+	{
+		BlenderInputHandler->UnregisterInputProcessor();
+	}
 }
 
 void FBlend4RealModule::OnEndPIE(bool bIsSimulating)
 {
+	// Re-register the input processor so it can intercept keys again (including for transient mode)
+	if (BlenderInputHandler.IsValid())
+	{
+		BlenderInputHandler->RegisterInputProcessor();
+	}
+
 	// Re-enable if it was enabled before PIE started
 	if (bWasEnabledBeforePIE && BlenderInputHandler.IsValid() && !BlenderInputHandler->IsEnabled())
 	{

Source/Blend4Real/Private/Blend4RealInputProcessor.cpp

@@ -42,9 +42,8 @@ FBlend4RealInputProcessor::~FBlend4RealInputProcessor()
 
 void FBlend4RealInputProcessor::RegisterInputProcessor()
 {
-	if (bIsEnabled && FSlateApplication::IsInitialized())
+	if (FSlateApplication::IsInitialized())
 	{
-		PlatformInputs::InitializeKeyboardLayoutCache();
 		FSlateApplication::Get().RegisterInputPreProcessor(SharedThis(this));
 	}
 }
@@ -59,6 +58,9 @@ void FBlend4RealInputProcessor::Init(TSharedPtr<ILevelEditor>)
 	GLevelEditorModeTools().SetShowWidget(true);
 	GLevelEditorModeTools().SaveConfig();
 
+	// Always register so we can intercept transform keys (G/R/S) for transient activation even when disabled
+	RegisterInputProcessor();
+
 	// Load saved enabled state from global editor settings (stored in user's AppData, not project)
 	bool bWasEnabled = false;
 	GConfig->GetBool(TEXT("Blend4Real"), TEXT("bEnabled"), bWasEnabled, GEditorSettingsIni);
@@ -76,11 +78,19 @@ void FBlend4RealInputProcessor::UnregisterInputProcessor()
 {
 	if (FSlateApplication::IsInitialized())
 	{
-		PlatformInputs::ShutdownKeyboardLayoutCache();
 		FSlateApplication::Get().UnregisterInputPreProcessor(SharedThis(this));
 	}
 }
 
+void FBlend4RealInputProcessor::EndTransientModeIfActive()
+{
+	if (bTransientMode)
+	{
+		bTransientMode = false;
+		ToggleEnabled();
+	}
+}
+
 void FBlend4RealInputProcessor::ToggleEnabled(const bool bInvalidateRender)
 {
 	bIsEnabled = !bIsEnabled;
@@ -110,9 +120,12 @@ void FBlend4RealInputProcessor::ToggleEnabled(const bool bInvalidateRender)
 		{
 			ViewportClient->Invalidate();
 		}
-		else if (GEditor && GEditor->GetActiveViewport())
+		else if (GEditor)
 		{
-			GEditor->GetActiveViewport()->Invalidate();
+			if (FViewport* ActiveViewport = GEditor->GetActiveViewport())
+			{
+				ActiveViewport->Invalidate();
+			}
 		}
 	}
 
@@ -122,13 +135,13 @@ void FBlend4RealInputProcessor::ToggleEnabled(const bool bInvalidateRender)
 
 	if (bIsEnabled)
 	{
-		RegisterInputProcessor();
+		PlatformInputs::InitializeKeyboardLayoutCache();
 		PivotVisualizationController->Enable();
 		UE_LOG(LogTemp, Display, TEXT("Blender Controls: Enabled"));
 	}
 	else
 	{
-		UnregisterInputProcessor();
+		PlatformInputs::ShutdownKeyboardLayoutCache();
 		PivotVisualizationController->Disable();
 		UE_LOG(LogTemp, Display, TEXT("Blender Controls: Disabled"));
 	}
@@ -232,9 +245,44 @@ void FBlend4RealInputProcessor::Tick(const float DeltaTime, FSlateApplication& S
 
 bool FBlend4RealInputProcessor::HandleKeyDownEvent(FSlateApplication& SlateApp, const FKeyEvent& InKeyEvent)
 {
+	// Instant Blender Controls: when disabled, intercept transform keys to activate transient mode.
 	if (!bIsEnabled)
 	{
-		return false;
+		const UBlend4RealSettings* Settings = UBlend4RealSettings::Get();
+		if (!Settings || !Settings->bInstantBlenderControls)
+		{
+			return false;
+		}
+
+		const FVector2D MousePosition = SlateApp.GetCursorPos();
+		const FName ViewportFilter = Settings->bInstantControlsLevelOnly ? FName("SLevelViewport") : NAME_None;
+		if (!Blend4RealUtils::IsMouseOverViewport(MousePosition, ViewportFilter))
+		{
+			return false;
+		}
+
+		ETransformMode TransientTransformMode;
+		if (UBlend4RealSettings::MatchesChord(Settings->InstantTranslationKey, InKeyEvent))
+		{
+			TransientTransformMode = ETransformMode::Translation;
+		}
+		else if (UBlend4RealSettings::MatchesChord(Settings->InstantRotationKey, InKeyEvent))
+		{
+			TransientTransformMode = ETransformMode::Rotation;
+		}
+		else if (UBlend4RealSettings::MatchesChord(Settings->InstantScaleKey, InKeyEvent))
+		{
+			TransientTransformMode = ETransformMode::Scale;
+		}
+		else
+		{
+			return false;
+		}
+
+		bTransientMode = true;
+		ToggleEnabled();
+		TransformController->BeginTransform(TransientTransformMode);
+		return true;
 	}
 
 	// Only process input if mouse is over a viewport (not requiring keyboard focus)
@@ -312,13 +360,15 @@ bool FBlend4RealInputProcessor::HandleKeyDownEvent(FSlateApplication& SlateApp,
 				TransformController->ApplyNumericTransform();
 			}
 			TransformController->EndTransform(true);
+			EndTransientModeIfActive();
 			return true;
 		}
 
 		// Escape cancels transform
 		if (Key == EKeys::Escape && ModMask == 0)
 		{
 			TransformController->EndTransform(false);
+			EndTransientModeIfActive();
 			return true;
 		}
 
@@ -393,7 +443,6 @@ bool FBlend4RealInputProcessor::HandleMouseMoveEvent(FSlateApplication& SlateApp
 	const FVector2D Delta = CurrentPosition - LastMousePosition;
 	LastMousePosition = CurrentPosition;
 
-
 	// For ongoing operations (navigation/transform), continue processing even if mouse moves outside viewport
 	// This ensures smooth camera movement and transforms when mouse drags outside viewport
 	const bool bInOperation = NavigationController->IsNavigating() || TransformController->IsTransforming();
@@ -502,11 +551,13 @@ bool FBlend4RealInputProcessor::HandleMouseButtonDownEvent(FSlateApplication& Sl
 		if (UBlend4RealSettings::MatchesChord(Settings->ApplyTransformKey, MouseEvent))
 		{
 			TransformController->EndTransform(true);
+			EndTransientModeIfActive();
 			return true;
 		}
 		if (UBlend4RealSettings::MatchesChord(Settings->CancelTransformKey, MouseEvent))
 		{
 			TransformController->EndTransform(false);
+			EndTransientModeIfActive();
 			return true;
 		}
 	}

Source/Blend4Real/Public/Blend4RealInputProcessor.h

@@ -16,6 +16,16 @@ class UViewportOrbitInteraction;
 /**
  * Input processor for Blender-style controls in Unreal Editor.
  * Acts as a thin dispatcher routing input to specialized controllers.
+ *
+ * Always registered as a Slate input pre-processor. Supports two activation modes:
+ *
+ * - Persistent mode: toggled via the toolbar button. Blend4Real stays enabled until
+ *   explicitly toggled off. All Blender controls (transforms, navigation, selection) are active.
+ *
+ * - Transient mode (opt-in via "Instant Blender Controls" setting): pressing a transform key
+ *   (G/R/S) while Blend4Real is disabled temporarily activates it for the duration of the
+ *   transform. Once confirmed (LMB/Enter/Space) or cancelled (RMB/Escape), Blend4Real
+ *   disables itself and returns to standard Unreal controls.
  */
 class FBlend4RealInputProcessor : public TSharedFromThis<FBlend4RealInputProcessor>, public IInputProcessor
 {
@@ -35,13 +45,19 @@ class FBlend4RealInputProcessor : public TSharedFromThis<FBlend4RealInputProcess
 
 	void ToggleEnabled(const bool bInvalidateRender = true);
 	bool IsEnabled() const { return bIsEnabled; }
-
-private:
 	void RegisterInputProcessor();
 	void UnregisterInputProcessor();
+
+private:
 	void Init(TSharedPtr<ILevelEditor> InLevelEditor);
 
+	/** End transient mode if active: clears the flag and disables Blend4Real. */
+	void EndTransientModeIfActive();
+
 	bool bIsEnabled = false;
+
+	/** When true, Blend4Real was activated by a transform key press and will auto-disable when the transform ends. */
+	bool bTransientMode = false;
 	bool bCursorHidden = false;
 	FVector2D LastMousePosition = FVector2D::ZeroVector;
 	FIntPoint PreNavigationCursorPos = FIntPoint::ZeroValue;

Source/Blend4Real/Public/Blend4RealSettings.h

@@ -33,6 +33,32 @@ class BLEND4REAL_API UBlend4RealSettings : public UDeveloperSettings
 	UPROPERTY(Config, EditAnywhere, Category = "Navigation", meta = (DisplayName = "Orbit Mode", ToolTip = "Controls how the camera orbits when using middle mouse button"))
 	EBlend4RealOrbitMode OrbitMode = EBlend4RealOrbitMode::OrbitAroundMouseProjection;
 
+	// Instant Blender Controls: press G/R/S to start a transform without enabling Blend4Real first.
+	// Blend4Real activates automatically for the duration of the transform, then returns to standard Unreal controls.
+	UPROPERTY(Config, EditAnywhere, Category = "General", meta = (DisplayName = "Instant Controls",
+		ToolTip = "When enabled, pressing a transform key (G/R/S) over a viewport will temporarily activate Blender controls for that transform. Once confirmed or cancelled, controls return to standard Unreal behavior. This works independently of the toolbar toggle."))
+	bool bInstantBlenderControls = false;
+
+	UPROPERTY(Config, EditAnywhere, Category = "General", meta = (DisplayName = "Instant Controls Level Viewport Only",
+		EditCondition = "bInstantBlenderControls",
+		ToolTip = "When enabled, Instant Blender Controls only activates in the Level Editor viewport, not in Blueprint or other viewports."))
+	bool bInstantControlsLevelOnly = true;
+
+	UPROPERTY(Config, EditAnywhere, Category = "General", meta = (DisplayName = "Instant Grab Key",
+		EditCondition = "bInstantBlenderControls",
+		ToolTip = "Key to start a grab/translate transform in Instant Blender Controls mode."))
+	FInputChord InstantTranslationKey = FInputChord(EKeys::G);
+
+	UPROPERTY(Config, EditAnywhere, Category = "General", meta = (DisplayName = "Instant Rotation Key",
+		EditCondition = "bInstantBlenderControls",
+		ToolTip = "Key to start a rotation transform in Instant Blender Controls mode."))
+	FInputChord InstantRotationKey = FInputChord(EKeys::R);
+
+	UPROPERTY(Config, EditAnywhere, Category = "General", meta = (DisplayName = "Instant Scale Key",
+		EditCondition = "bInstantBlenderControls",
+		ToolTip = "Key to start a scale transform in Instant Blender Controls mode."))
+	FInputChord InstantScaleKey = FInputChord(EKeys::S, EModifierKey::Shift);
+
 	// Helper methods to get orbit flags
 	bool ShouldOrbitAroundSelection() const { return OrbitMode == EBlend4RealOrbitMode::OrbitAroundSelection; }
 	bool ShouldOrbitAroundMouseHit() const { return OrbitMode == EBlend4RealOrbitMode::OrbitAroundMouseProjection; }