Try the demo

This walkthrough completes one city-building session using the shipped DemoMap layout and default Blueprint settings.

Goal

Place roads, build one residential and one commercial structure, collect income, watch population grow, and save your city.

Placement flow

sequenceDiagram
  participant You
  participant PC as BP_CBT_PlayerController
  participant Road as BP_Road
  participant Bld as BP_CBT_BaseBuilding
  participant SG as BP_CBT_Singleton
  You->>PC: Open road tool (WBP_RoadFrame)
  PC->>Road: Drag spline with PrimaryClick
  Road->>PC: CreateRoad → BP_RoadTile
  You->>PC: Select House (WBP_BuildingSelect)
  PC->>Bld: Preview on grid
  You->>PC: PrimaryClick place
  Bld->>SG: Construction → AddPopulation
  You->>PC: Select Shop, place near road
  Bld->>SG: CollectIncome

Steps

1. Launch

1. Open the template and press Play on DemoMap (or start at MainMenu → Play Game).
2. Confirm WBP_PlayerHUD shows currency, XP, level, and population bars.
3. New games start with Starting Currency 100000 and Starting Premium Cash 10 (BP_CBT_PlayerController class defaults).

2. Lay roads

1. Open the road tool (WBP_RoadFrame on the HUD).
2. Click to set spline points along an empty area; right-click or cancel to exit preview.
3. Confirm CreateRoad spawns BP_RoadTile segments snapped to BP_CBT_Grid.

Note

Buildings require bIsNearRoad — leave at least one road tile adjacent to every building footprint.

3. Place a house

1. Open the residential tab on WBP_BuildingFrame.
2. Select House (BP_CBT_House) in WBP_BuildingSelect.
3. Move the preview ghost; press Z / C to rotate.
4. Primary-click to place. Internal_StartConstruction should return Success when currency and road rules pass.
5. Watch WBP_ConstructionTimer count down ConstructionTime, then AddPopulation on the singleton.

4. Place a shop

1. Switch to the commercial tab.
2. Select Shop (BP_CBT_Shop) — shipped Unlock Level is 2, so you may need one level-up before it appears in the picker.
3. Place adjacent to the same road network (cost: 5 currency + 12 premium cash).
4. After construction, workers hire over time (Worker Add Delay 1.5 s, max 10). Income ticks every Profit Delay 60 s at Revenue Per Worker 268.
5. Click WBP_CollectCurrency on the building (bAutoCollectIncome is false on the shipped class).

5. Run the simulation

HUD control	ESimulationState
Pause / Play	Paused ↔ NormalSpeed
Normal speed	NormalSpeed
Double speed	DoubleSpeed

Observe BP_CBT_TimeOfDay switching day/night — building window lights and BP_Vehicle traffic react via OnDayStarted / OnNightStarted.

6. Save

1. Click SaveGameBtn on WBP_PlayerHUD.
2. Internal_SaveGame writes to slot CityBuilderSaveGame.
3. Stop PIE, press Play again, and use LoadGameBtn (or MainMenu → Load Game) to verify persistence.

What to verify

Check	Expected behaviour
Road on invalid terrain	Preview clears; tiles only on valid grid cells
Building far from road	EStartConstructionResult → NotNearRoad; no currency spent
Insufficient funds	NotEnoughMoney; preview remains
Level up	WBP_LevelUpNotification when XP threshold met — new buildings respect UnlockLevel
Bulldoze	Delete or WBP_Bulldoze → BulldozePrepare removes actor and updates save arrays

Next

• Tune economy and progression — adjust costs and income
• Blueprint reference — full property list