Unreal Engine 5.7 — UI Module Reference¶
Last verified: 2026-02-13 Knowledge Gap: UE 5.7 UMG and CommonUI improvements
Overview¶
UE 5.7 UI systems: - UMG (Unreal Motion Graphics): Visual widget-based UI (RECOMMENDED) - CommonUI: Cross-platform input-aware UI framework (console/PC) - Slate: Low-level C++ UI (engine/editor UI)
UMG (Unreal Motion Graphics)¶
Create Widget Blueprint¶
- Content Browser > User Interface > Widget Blueprint
- Open Widget Designer
- Drag widgets from Palette: Button, Text, Image, ProgressBar, etc.
Basic UMG Setup in C++¶
Create and Display Widget¶
#include "Blueprint/UserWidget.h"
UPROPERTY(EditAnywhere, Category = "UI")
TSubclassOf<UUserWidget> HealthBarWidgetClass;
void AMyCharacter::BeginPlay() {
Super::BeginPlay();
// Create widget
UUserWidget* HealthBarWidget = CreateWidget<UUserWidget>(GetWorld(), HealthBarWidgetClass);
// Add to viewport
HealthBarWidget->AddToViewport();
}
Remove Widget¶
HealthBarWidget->RemoveFromParent();
Access Widget Elements from C++¶
Bind to Widget Elements¶
UCLASS()
class UMyHealthWidget : public UUserWidget {
GENERATED_BODY()
public:
// ✅ Bind to widget elements (must match names in Widget Blueprint)
UPROPERTY(meta = (BindWidget))
TObjectPtr<UTextBlock> HealthText;
UPROPERTY(meta = (BindWidget))
TObjectPtr<UProgressBar> HealthBar;
void UpdateHealth(int32 CurrentHealth, int32 MaxHealth) {
HealthText->SetText(FText::FromString(FString::Printf(TEXT("%d / %d"), CurrentHealth, MaxHealth)));
HealthBar->SetPercent((float)CurrentHealth / MaxHealth);
}
};
Common UMG Widgets¶
Text Block¶
UPROPERTY(meta = (BindWidget))
TObjectPtr<UTextBlock> ScoreText;
ScoreText->SetText(FText::FromString(TEXT("Score: 100")));
ScoreText->SetColorAndOpacity(FLinearColor::Green);
Button¶
UPROPERTY(meta = (BindWidget))
TObjectPtr<UButton> PlayButton;
void NativeConstruct() override {
Super::NativeConstruct();
// Bind button click
PlayButton->OnClicked.AddDynamic(this, &UMyMenuWidget::OnPlayClicked);
}
UFUNCTION()
void OnPlayClicked() {
UE_LOG(LogTemp, Warning, TEXT("Play clicked"));
}
Image¶
UPROPERTY(meta = (BindWidget))
TObjectPtr<UImage> PlayerAvatar;
PlayerAvatar->SetBrushFromTexture(AvatarTexture);
PlayerAvatar->SetColorAndOpacity(FLinearColor::White);
Progress Bar¶
UPROPERTY(meta = (BindWidget))
TObjectPtr<UProgressBar> HealthBar;
HealthBar->SetPercent(0.75f); // 75%
HealthBar->SetFillColorAndOpacity(FLinearColor::Red);
Slider¶
UPROPERTY(meta = (BindWidget))
TObjectPtr<USlider> VolumeSlider;
void NativeConstruct() override {
Super::NativeConstruct();
VolumeSlider->OnValueChanged.AddDynamic(this, &UMyWidget::OnVolumeChanged);
}
UFUNCTION()
void OnVolumeChanged(float Value) {
// Value is 0.0 - 1.0
UE_LOG(LogTemp, Warning, TEXT("Volume: %f"), Value);
}
EditableTextBox (Input Field)¶
UPROPERTY(meta = (BindWidget))
TObjectPtr<UEditableTextBox> PlayerNameInput;
void NativeConstruct() override {
Super::NativeConstruct();
PlayerNameInput->OnTextChanged.AddDynamic(this, &UMyWidget::OnNameChanged);
}
UFUNCTION()
void OnNameChanged(const FText& Text) {
FString PlayerName = Text.ToString();
}
UMG Animations¶
Play Animation¶
UPROPERTY(Transient, meta = (BindWidgetAnim))
TObjectPtr<UWidgetAnimation> FadeInAnimation;
void ShowUI() {
PlayAnimation(FadeInAnimation);
}
Stop Animation¶
StopAnimation(FadeInAnimation);
Canvas Panel (Layout)¶
Canvas Panel (Absolute Positioning)¶
// Use in Widget Blueprint for absolute positioning
// Anchor widgets to corners/edges for responsive UI
Vertical Box (Stack Vertically)¶
// Auto-stacks children vertically
Horizontal Box (Stack Horizontally)¶
// Auto-stacks children horizontally
Grid Panel (Grid Layout)¶
// Arranges children in a grid
World Space UI (3D UI)¶
Widget Component (3D UI in World)¶
#include "Components/WidgetComponent.h"
UWidgetComponent* HealthBarWidget = CreateDefaultSubobject<UWidgetComponent>(TEXT("HealthBar"));
HealthBarWidget->SetupAttachment(RootComponent);
HealthBarWidget->SetWidgetClass(HealthBarWidgetClass);
HealthBarWidget->SetWidgetSpace(EWidgetSpace::World); // 3D world space
HealthBarWidget->SetDrawSize(FVector2D(200, 50));
Input Handling in UMG¶
Override Keyboard Input¶
UCLASS()
class UMyWidget : public UUserWidget {
GENERATED_BODY()
public:
virtual FReply NativeOnKeyDown(const FGeometry& InGeometry, const FKeyEvent& InKeyEvent) override {
if (InKeyEvent.GetKey() == EKeys::Escape) {
// Handle Escape key
CloseMenu();
return FReply::Handled();
}
return Super::NativeOnKeyDown(InGeometry, InKeyEvent);
}
};
CommonUI (Cross-Platform Input)¶
Enable CommonUI Plugin¶
// Enable: Edit > Plugins > CommonUI
// Restart editor
Use CommonUI Widgets¶
// CommonUI widgets:
// - CommonActivatableWidget: Base for screens/menus
// - CommonButtonBase: Input-aware button (gamepad + mouse)
// - CommonTextBlock: Text with styling
CommonActivatableWidget Example¶
UCLASS()
class UMyMenuWidget : public UCommonActivatableWidget {
GENERATED_BODY()
public:
virtual void NativeOnActivated() override {
Super::NativeOnActivated();
// Menu activated (shown)
}
virtual void NativeOnDeactivated() override {
Super::NativeOnDeactivated();
// Menu deactivated (hidden)
}
};
HUD Class (Alternative to UMG)¶
Create HUD¶
UCLASS()
class AMyHUD : public AHUD {
GENERATED_BODY()
public:
virtual void DrawHUD() override {
Super::DrawHUD();
// Draw text
DrawText(TEXT("Score: 100"), FLinearColor::White, 50, 50);
// Draw texture
DrawTexture(CrosshairTexture, Canvas->SizeX / 2, Canvas->SizeY / 2, 32, 32);
}
};
Performance Tips¶
Optimize UMG¶
// Invalidation boxes: Only redraw when content changes
// Add "Invalidation Box" widget to Widget Blueprint
// Disable tick if not needed
bIsFocusable = false;
SetVisibility(ESlateVisibility::Collapsed); // Collapsed = not rendered
Debugging¶
UI Debug Commands¶
// Console commands:
// widget.debug - Show widget hierarchy
// Slate.ShowDebugOutlines 1 - Show widget bounds
// stat slate - Show Slate performance
Sources¶
- https://docs.unrealengine.com/5.7/en-US/umg-ui-designer-for-unreal-engine/
- https://docs.unrealengine.com/5.7/en-US/commonui-plugin-for-advanced-user-interfaces-in-unreal-engine/