CrimsonCommon · Lesson 3 of 4

Adopt the Modular Base Classes

Beginner6 minSetupBlueprints

Before you start

  • Completed: Enable the Plugin
  • A project with a Character, controllers, game mode/state, and game instance to reparent
Video coming soon

Chapters

Swap base classes

Replace Unreal's default framework classes with the Crimson modular equivalents:

ReplaceWith
ACharacterACrimsonModularCharacter
APawnACrimsonModularPawn
APlayerControllerACrimsonModularPlayerController
APlayerStateACrimsonModularPlayerState
AGameModeBase / AGameModeACrimsonModularGameModeBase / ACrimsonModularGameMode
AGameStateBase / AGameStateACrimsonModularGameStateBase / ACrimsonModularGameState
UGameInstanceUCrimsonCommonGameInstance
Adopt incrementally
You don't have to swap everything at once. The base classes are independent — reparent the Character today and the Player State later, and use only the ones your project actually has.
Also: AI controllers
If your project uses a custom AI controller, there's ACrimsonModularAIController (base AAIController) — reparent it the same way.

Reparent in Blueprint

You don't recreate anything — you reparent. Open each core Blueprint, click Class Settings, and in the Details panel set Parent Class to the Crimson modular type. Compile and Save. Your components and graphs are preserved; only the base changes.

The Game Instance is set in Project Settings → Maps & Modes → Game Instance Class — point it at CrimsonCommonGameInstance (or your own Blueprint reparented onto it).

Change inheritance in C++

Same idea, expressed as inheritance — change what your classes extend, fix the includes, and rebuild.

cpp
// Before
class ACrimsonStartCharacter : public ACharacter { /* ... */ };


// After
#include "Actors/CrimsonModularCharacter.h"
class ACrimsonStartCharacter : public ACrimsonModularCharacter { /* ... */ };
Reminder
Referencing CrimsonCommon types requires the module add from the previous lesson: PublicDependencyModuleNames.Add("CrimsonCommon").

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