claw-code/.guardrails/examples/cpp/unreal-ui

Unreal Engine CommonUI - 2026 Best Practices

Overview

This module demonstrates production-ready Unreal Engine 5.4+ CommonUI plugin implementations with volumetric UI, GPU instancing, and systemic rulesets for physics/chemistry interactions.

Architecture

Stack

• Unreal Engine 5.4+ - Latest UE5 features
• CommonUI Plugin - Unified UI framework
• Volumetric Rendering - Z-depth UI layers
• GPU Instancing - Batch UI element rendering

2026 Best Practices

Core Design Patterns

CommonUI Framework

// CommonUI widget creation
auto* hudWidget = CreateWidget<UCommonUserWidget>(GetWorld(), HUDClass);
hudWidget->Initialize();

Volumetric UI with Z-Depth

• Holographic inventory previews
• Parallax scrolling for UI layers
• Eye-tracking focus indicators

GPU Instancing

• Batched UI element rendering
• Shared material batches
• Efficient VR/AR UI rendering

Game Core Loop Integration

• Action Phase: Combat HUD with reactive health bars
• Reward Phase: Loot reveal with volumetric glow
• Upgrade Phase: Skill tree with Z-depth nodes

DDA 3.0 (Dynamic Difficulty Adjustment)

Enemy AI Heuristic Adjustment

• UI opacity adapts to player stress
• Visual complexity reduction for difficult tier
• Enhanced feedback for relaxed tier

Accessibility (WCAG 3.0+)

Colorblindness Independence

// Shape + icon redundancy
HealthBar->SetShapeIndicator(true); // Not just color

Eye-Tracking Support

• Dwell-based selection (150ms threshold)
• Pupil dilation stress detection
• Blink confirmation pattern

Spatial Computing (XR)

Volumetric Rendering

• Z-depth parallax (0.3f factor)
• Holographic item previews
• Eye-tracking focus rings

GPU Instancing for XR

• Batched VR UI rendering
• Shared material for efficiency
• Low-latency UI updates

Ethical Engagement

Rest-State Mechanics

// Mandatory calm state after 45-minute sessions
if (SessionDuration > 45) {
    EnterRestState();
}

Transparent Loot Tables

• Drop rates displayed inline
• Pity timer visualization
• No obfuscated RNG indicators

Systemic Rulesets

Physics/Chemistry Interaction

• UI elements obey physics rules
• Chemical reaction metaphors for combos
• Emergent gameplay through interaction

File Structure

unreal-ui/
  README.md             - This documentation
  CommonUI.cpp          - UE5 CommonUI example
  volumetric-ui.cpp     - Volumetric UI with Z-depth
  gpu-instancing.cpp    - GPU instancing for UI
  systemic-ruleset.cpp  - Physics/chemistry ruleset

Usage

// Initialize CommonUI system
auto* uiSystem = UEuralCommonUI::Get();
uiSystem->Initialize();

// Enable volumetric rendering
uiSystem->SetVolumetricDepth(0.5f);

// Enable GPU instancing
uiSystem->EnableGPUInstancing(true);

Testing

Run Unreal UI tests:

UnrealEditor -run=test -test=examples/cpp/unreal-ui

References

• Unreal Engine CommonUI Plugin
• UE5 Volumetric Rendering
• WCAG 3.0 Accessibility Guidelines