constructing_a_building_system.md

Constructing a Building

Objective

Create a system where the player can:

1. Select a worker unit.
2. Issue a command to construct a building at a specified location.
3. Manage construction progress, completion, and any dependencies.

Step 1: Setting Up the Root Scene

1. Create the Root Scene:

   • Create a new Node3D scene and save it as MainScene.tscn.
   • Add the following child nodes:
     • DirectionalLight3D: For consistent global lighting.
     • Camera3D: Position it for a top-down RTS perspective.
     • PlaneMesh: To act as the ground. Set its size and material as needed for your environment.

   Screenshot Suggestion: Show the scene hierarchy with MainScene, light, camera, and plane nodes.

2. Environment Settings:

   • Configure the environment for a basic 3D appearance:
     • In the WorldEnvironment node, add a default environment resource.
     • Adjust ambient lighting and background to your preference.

   Screenshot Suggestion: Show the environment configuration.

Step 2: Adding RTSController and Managers

1. Add RTSController:

   • Add an RTSController node to the MainScene.
   • Attach the RTSController.gd script to it.

2. Add Managers:

   • Add the following child nodes under the RTSController:
     • SelectionManager: Attach SelectionManager.gd.
     • CommandManager: Attach CommandManager.gd.
     • ConstructionManager: Attach ConstructionManager.gd.

   Screenshot Suggestion: Show the RTSController with its child managers in the hierarchy.

Step 3: Adding BuildingEntity Scene

1. Create the BuildingEntity Scene:

   • Create a new scene with a Node3D as the root.
   • Add the following child nodes:
     • MeshInstance3D: For the building's visual representation.
     • QueueComponent: For managing production (e.g., units from the building).
     • DamageableComponent: Optional, for destructible buildings.

   Screenshot Suggestion: Show the BuildingEntity scene hierarchy.

2. Save and Configure:

   • Save the scene as BuildingEntity.tscn.
   • Add the scene to a folder like resources/building_scenes.

Step 4: Implementing Construction Logic

1. Configure ConstructionManager:
   • Ensure the ConstructionManager script handles construction requests:
     • Spawning the BuildingEntity at the specified position.
     • Using worker units (if provided) to handle construction progress.

func start_construction(building_scene: PackedScene, target_position: Vector3, worker: UnitEntity = null):
    if worker:
        worker.state_machine.transition_to("build")
    else:
        var building_instance = building_scene.instance()
        building_instance.global_transform.origin = target_position
        get_tree().current_scene.add_child(building_instance)
        emit_signal("construction_started", building_scene.resource_path, null)
        emit_signal("construction_completed", building_instance)

1. Worker Logic:
   • Ensure the UnitEntity includes a BuildState for constructing buildings:
     • Adjust construction progress over time.
     • Transition back to IdleState when the building is complete.

Step 5: Testing and Enhancements

1. Test Construction:
   • Run the game.
   • Select a worker unit and issue a build command for a building.
   • Verify that the building spawns and transitions to the completed state.
2. Enhancements:
   • Add a placement preview for buildings before finalizing their position.
   • Add construction animations or effects during the building process.