CrimsonUI · Lesson 1 of 9

How CrimsonUI Is Wired

Beginner2 minOverview

Before you start

  • The CrimsonCommon — Setup & Foundations course
  • Unreal Engine 5.8+
Video coming soon

Chapters

The architecture

CrimsonUI is a game-agnostic UI foundation built on Epic's CommonUI. A policy creates one root layout per local player; the layout registers layers keyed by gameplay tags (UI.Layer.Game, UI.Layer.Menu, …); and your screens push onto those layers. Every pushed widget declares how input routes — game, menu, or both — so 'menu open, game input off' stops being manual bookkeeping.

Around that core it ships dialogs, MVVM bases, world-space indicators, context menus, tabs, lists, drag-drop, and touch input — every class a base to subclass, none of it game-specific.

Dependencies

Needs one Crimson plugin — CrimsonCommon (the policy/layout base layer actually lives there) — plus engine plugins CommonUI, EnhancedInput, GameplayAbilities, and ModelViewViewModel, which the editor enables for you.

What we'll build

  1. Enable the plugin
  2. Set the three boot classes
  3. Give CommonUI its Click and Back actions
  4. Register layers in a root layout, wired to a policy
  5. Push a HUD, then screens and dialogs
UI is never authoritative
Nothing in CrimsonUI replicates and dedicated servers create zero UI. Route widget events through server RPCs or GAS — the UI only shows state.

Resources