Migrate into your project

Use this when you want city-builder systems inside a project you already have, instead of extending the standalone FAB template.

Migration overview

flowchart LR
  FAB["FAB template project"] --> Migrate["Asset Actions → Migrate"]
  Migrate --> Target["Your project Content/"]
  Target --> Collision["Add GenericBuilding + GenericRoad channels"]
  Collision --> Maps["Set GameInstance + maps"]
  Maps --> Play["Play migrated DemoMap"]

Example — minimal migrate into `MyGame`

Assume your project lives at C:/Projects/MyGame/.

Open the City Builder Template FAB project.
In Content Browser, select the folder CityBuilderTemplate.
Right-click → Asset Actions → Migrate → choose C:/Projects/MyGame/Content/.
Confirm the dependency list (includes meshes, materials, widgets, and Misc/ST_CityBuilderTemplate).

Minimum folder:

Content/CityBuilderTemplate/
├── Blueprints/          (all subfolders)
├── Maps/                (DemoMap, MainMenu — optional but recommended)
├── Meshes/
├── Materials/
├── Textures/
├── Misc/
└── 1_BP_CBT_Tut_* …     (optional in-editor tutorials)

Project settings

Merge into your project’s Config/DefaultEngine.ini:

Maps and game instance

[/Script/EngineSettings.GameMapsSettings]
GlobalDefaultGameMode=/Game/CityBuilderTemplate/Blueprints/BP_CBT_GameMode.BP_CBT_GameMode_C
GameInstanceClass=/Game/CityBuilderTemplate/Blueprints/BP_CBT_GameInstance.BP_CBT_GameInstance_C

Point EditorStartupMap / GameDefaultMap at migrated maps or your own menu that calls BP_CBT_GameInstance.

Collision channels

[/Script/Engine.CollisionProfile]
+DefaultChannelResponses=(Channel=ECC_GameTraceChannel1,Name="GenericBuilding",DefaultResponse=ECR_Overlap,bTraceType=False,bStaticObject=False)
+DefaultChannelResponses=(Channel=ECC_GameTraceChannel2,Name="GenericRoad",DefaultResponse=ECR_Overlap,bTraceType=False,bStaticObject=False)
+Profiles=(Name="GenericBuilding",CollisionEnabled=QueryAndPhysics,ObjectTypeName="GenericBuilding",CustomResponses=,HelpMessage="Collision Preset for all generic building types.",bCanModify=True)
+Profiles=(Name="GenericRoad",CollisionEnabled=QueryAndPhysics,ObjectTypeName="GenericRoad",CustomResponses=,HelpMessage="Collision Preset for all generic road types.",bCanModify=True)

Or create GenericBuilding and GenericRoad object channels in Project Settings → Collision.

Without these channels, Internal_CheckNearRoad and placement traces fail silently.

Plugins

The template .uproject enables:

Plugin	Required for
GuidedTutorials	In-editor `_Tut_` tutorial assets
ModelContextProtocol	Optional — editor MCP tooling

Enable GuidedTutorials in your target project if you migrated tutorial assets.

Input

Copy relevant action/axis mappings from the template Config/DefaultInput.ini or merge into your Enhanced Input setup:

PrimaryClick, SecondaryClick, Delete
MoveForward, MoveRight, CameraRotate
CameraZoomIn, CameraZoomOut
BuildingRotateLeft, BuildingRotateRight
PauseGame

BP_CBT_PlayerPawn expects these legacy action names unless you rebind in the controller.

First playable test map

Migrate content (above).
Open migrated CityBuilderTemplate/Maps/DemoMap (or duplicate to Content/MyGame/Maps/CityTest).
World Settings:
- Game Mode Override → BP_CBT_GameMode
Ensure the level contains:
- BP_CBT_Grid
- BP_CBT_Singleton
- BP_CBT_TimeOfDay
- BP_CBT_PlayerController / BP_CBT_PlayerPawn spawn (game mode default pawn)
Press Play — place a road and BP_CBT_House.

Integrate with your game (optional)

Approach	Steps
Sub-level	Keep city in DemoMap; open as sub-level from your hub map via BP_CBT_GameInstance → OpenLevel
Mode switch	Set your menu Game Instance to BP_CBT_GameInstance only on city levels
Systems only	Migrate `Blueprints/` without maps; place Grid, Singleton, and TimeOfDay in your own level

Save slot

Default slot name CityBuilderSaveGame is defined in BP_CBT_ObjectMacros / GetSaveGameSlotNameAndIndex.

Rename only if you change it in one place and update WBP_MainMenu + WBP_PlayerHUD save buttons.

Troubleshooting

Issue	Fix
Buildings won’t place	Check GenericRoad overlaps and bIsNearRoad
HUD missing	BP_CBT_PlayerController must create WBP_PlayerHUD
Save fails	Confirm BP_CBT_SaveGame class on game instance
Wrong map on launch	Update GameMapsSettings in `DefaultEngine.ini`
Grid misaligned	Match BP_CBT_PlayerController → Grid Size and BP_CBT_Grid → Default Grid Size to level scale