SnapScaleEnabled

SnapScaleEnabled

#Overview

name: SnapScaleEnabled

The value of this variable can be defined or overridden in .ini config files. 1 .ini config file referencing this setting variable.

It is referenced in 9 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of SnapScaleEnabled is to control whether actor sizes will snap to the grid in the Unreal Engine editor’s viewport. This setting is primarily used for level editing and actor manipulation within the editor.

This setting variable is primarily used by the Level Editor subsystem of Unreal Engine, specifically in the viewport interaction and manipulation tools. It’s referenced in several modules including LevelEditor, UnrealEd, and VREditor.

The value of this variable is set in the ULevelEditorViewportSettings class, which is a configuration class for Level Editor viewport settings. It can be toggled through various editor actions and UI elements, such as toolbar buttons or menu items.

SnapScaleEnabled interacts with other snapping and grid-related variables, such as GridEnabled for location snapping and ScalingGridSizes for determining the snap increments.

Developers should be aware that this variable affects the behavior of scaling operations in the viewport. When enabled, it forces actor scaling to align with the grid, which can be useful for precise positioning but may also limit fine-grained control.

Best practices when using this variable include:

  1. Providing a clear way for users to toggle this setting in the editor UI.
  2. Considering the appropriate grid size when this setting is enabled, as it directly affects the granularity of scaling operations.
  3. Ensuring that the snapping behavior is consistent across different editor tools and modes that involve scaling.
  4. Documenting the behavior for end-users, especially level designers, so they understand how it affects their workflow.

#Setting Variables

#References In INI files

Location: <Workspace>/Engine/Config/BaseEditorPerProjectUserSettings.ini:416, section: [/Script/UnrealEd.LevelEditorViewportSettings]

#References in C++ code

#Callsites

This variable is referenced in the following C++ source code:

#Loc: <Workspace>/Engine/Source/Editor/LevelEditor/Private/Elements/Component/ComponentElementLevelEditorViewportInteractionCustomization.cpp:192

Scope (from outer to inner):

file
function     void FComponentElementLevelEditorViewportInteractionCustomization::ValidateScale
lambda-function

Source code excerpt:

		int32 MaxAxisIndex = -1;
		const ULevelEditorViewportSettings* ViewportSettings = GetDefault<ULevelEditorViewportSettings>();
		bool SnapScaleAfter = ViewportSettings->SnapScaleEnabled;

		//Found the number of active axis
		//Found if we have to swap some sign
		for (int Axis = 0; Axis < 3; ++Axis)
		{
			if (bActiveAxes[Axis])

#Loc: <Workspace>/Engine/Source/Editor/LevelEditor/Private/Elements/Component/ComponentElementLevelEditorViewportInteractionCustomization.cpp:254

Scope (from outer to inner):

file
function     void FComponentElementLevelEditorViewportInteractionCustomization::ValidateScale
lambda-function

Source code excerpt:


			FVector::FReal AbsoluteScaleValue = InOriginalPreDragScale[MaxAxisIndex] + InOutScaleDelta[MaxAxisIndex];
			if (ViewportSettings->SnapScaleEnabled)
			{
				AbsoluteScaleValue = FMath::GridSnap(InOriginalPreDragScale[MaxAxisIndex] + InOutScaleDelta[MaxAxisIndex], (FVector::FReal)GEditor->GetScaleGridSize());
				SnapScaleAfter = false;
			}

			FVector::FReal ScaleRatioMax = AbsoluteScaleValue / InOriginalPreDragScale[MaxAxisIndex];

#Loc: <Workspace>/Engine/Source/Editor/LevelEditor/Private/LevelEditorActions.cpp:2199

Scope (from outer to inner):

file
function     void FLevelEditorActionCallbacks::ScaleGridSnap_Clicked

Source code excerpt:

void FLevelEditorActionCallbacks::ScaleGridSnap_Clicked()
{
	GUnrealEd->Exec( GetWorld(), *FString::Printf( TEXT("MODE SCALEGRID=%d"), !GetDefault<ULevelEditorViewportSettings>()->SnapScaleEnabled ? 1 : 0 ) );
}

bool FLevelEditorActionCallbacks::ScaleGridSnap_IsChecked()
{
	return GetDefault<ULevelEditorViewportSettings>()->SnapScaleEnabled;
}

bool FLevelEditorActionCallbacks::SaveAnimationFromSkeletalMeshComponent(AActor * EditorActor, AActor * SimActor, TArray<USkeletalMeshComponent*> & OutEditorComponents)
{
	FLevelEditorModule& LevelEditorModule = FModuleManager::GetModuleChecked<FLevelEditorModule>( TEXT("LevelEditor") );

#Loc: <Workspace>/Engine/Source/Editor/UnrealEd/Classes/Settings/LevelEditorViewportSettings.h:437

Scope (from outer to inner):

file
class        class ULevelEditorViewportSettings : public UObject

Source code excerpt:

	/** If enabled, actor sizes will snap to the grid. */
	UPROPERTY(EditAnywhere, config, Category=GridSnapping, meta=(DisplayName = "Enable Scale Snapping"))
	uint32 SnapScaleEnabled:1;

	/** If enabled, actors will snap to surfaces in the viewport when dragged around */
	UPROPERTY(config)
	FSnapToSurfaceSettings SnapToSurface;

private:

#Loc: <Workspace>/Engine/Source/Editor/UnrealEd/Private/STransformViewportToolbar.cpp:1002

Scope (from outer to inner):

file
function     ECheckBoxState STransformViewportToolBar::IsScaleGridSnapChecked

Source code excerpt:

ECheckBoxState STransformViewportToolBar::IsScaleGridSnapChecked() const
{
	return GetDefault<ULevelEditorViewportSettings>()->SnapScaleEnabled ? ECheckBoxState::Checked : ECheckBoxState::Unchecked;
}

void STransformViewportToolBar::HandleToggleLocationGridSnap( ECheckBoxState InState )
{
	GUnrealEd->Exec( GEditor->GetEditorWorldContext().World(), *FString::Printf( TEXT("MODE GRID=%d"), !GetDefault<ULevelEditorViewportSettings>()->GridEnabled ? 1 : 0 ) );
}

#Loc: <Workspace>/Engine/Source/Editor/UnrealEd/Private/STransformViewportToolbar.cpp:1033

Scope (from outer to inner):

file
function     void STransformViewportToolBar::HandleToggleScaleGridSnap

Source code excerpt:

void STransformViewportToolBar::HandleToggleScaleGridSnap(ECheckBoxState InState)
{
	GUnrealEd->Exec( GEditor->GetEditorWorldContext().World(), *FString::Printf( TEXT("MODE SCALEGRID=%d"), !GetDefault<ULevelEditorViewportSettings>()->SnapScaleEnabled ? 1 : 0 ) );
}

#undef LOCTEXT_NAMESPACE

#Loc: <Workspace>/Engine/Source/Editor/UnrealEd/Private/SnappingUtils.cpp:121

Scope (from outer to inner):

file
function     bool FEditorViewportSnapping::IsSnapScaleEnabled

Source code excerpt:

bool FEditorViewportSnapping::IsSnapScaleEnabled()
{
	return GetDefault<ULevelEditorViewportSettings>()->SnapScaleEnabled;
}

bool FEditorViewportSnapping::IsSnapToVertexEnabled(bool bIsPivot)
{
	if( GetDefault<ULevelEditorViewportSettings>()->bSnapVertices )
	{

#Loc: <Workspace>/Engine/Source/Editor/UnrealEd/Private/UnrealEdSrv.cpp:3047

Scope (from outer to inner):

file
function     bool UUnrealEdEngine::Exec_Mode

Source code excerpt:


		ULevelEditorViewportSettings* ViewportSettings = GetMutableDefault<ULevelEditorViewportSettings>();
		ViewportSettings->SnapScaleEnabled = DWord1;
		ViewportSettings->PostEditChange();

		FEditorSupportDelegates::UpdateUI.Broadcast();
	}

	if( FParse::Value(Str, TEXT("SNAPVERTEX="), DWord1) )

#Loc: <Workspace>/Engine/Source/Editor/VREditor/Private/VREditorActions.cpp:100

Scope (from outer to inner):

file
function     ECheckBoxState FVREditorActionCallbacks::GetScaleSnapState

Source code excerpt:

ECheckBoxState FVREditorActionCallbacks::GetScaleSnapState()
{
	return GetDefault<ULevelEditorViewportSettings>()->SnapScaleEnabled ? ECheckBoxState::Checked : ECheckBoxState::Unchecked;
}

void FVREditorActionCallbacks::OnScaleSnapSizeButtonClicked()
{
	const ULevelEditorViewportSettings* ViewportSettings = GetMutableDefault<ULevelEditorViewportSettings>();
	const int32 NumGridSizes = ViewportSettings->ScalingGridSizes.Num();