Skill v1.0.2

version: "1.0.2" name: godot-genre-rts description: "Expert blueprint for real-time strategy games including unit selection (drag box, shift-add), command systems (move, attack, gather), pathfinding (NavigationAgent2D with RVO avoidance), fog of war (SubViewport mask shader), resource economy (gather/build loop), and AI opponents (behavior trees, utility AI). Use for base-building RTS or tactical combat games. Trigger keywords: RTS, unit_selection, command_system, fog_of_war, pathfinding_RVO, resource_economy, command_queue."

NEVER Do (Expert Anti-Patterns)

Unit Logic & Pathfinding

• NEVER allow pathfinding "Jitter" when moving group units; strictly stagger path queries and enable RVO Avoidance only when units are in motion to save CPU cycles.
• NEVER update RVO avoidance every frame for all units; strictly use Avoidance Threading (Project Settings) and replace static units with NavigationObstacle.
• NEVER let units get stuck in infinite path loops; strictly implement a timeout and IDLE state if a destination is unreachable.
• NEVER use _process() on hundreds of individual units; strictly use a central UnitManager or _physics_process only when required.
• NEVER calculate unit visibility manually for Fog of War; strictly use a Shader-based mask (SubViewport + ColorRect) for GPU efficiency.
• NEVER process unit AI or pathfinding synchronously for mass groups; strictly offload to `WorkerThreadPool` and stagger path updates.
• NEVER use high-poly visual meshes as NavMesh source geometry; strictly use simplified Collision Shapes for baking.

Interaction & Commands

• NEVER forget Command Queuing (Shift-Click); strictly store an Array[Command] and implement a "Force Move/Attack" bypass.
• NEVER create excessive micromanagement; strictly automate low-level tasks like auto-aggro range and auto-return for resource gathering.
• NEVER use exact floating-point equality (==) for grid or timers; strictly use is_equal_approx() for deterministic triggers.
• NEVER rely on the visual SceneTree for selection data; strictly maintain a Typed Selection Set of RefCounted or Resource objects for deterministic serialization and netcode.
• NEVER forget Command Queuing; strictly implement a Command Pattern using serializable Dictionary or JSON states for save-game and multiplayer playback.
• NEVER forget to duplicate_deep() globally shared Resources; otherwise, modifying one unit's data (e.g., stats) affects all.

Performance & Simulation

• NEVER render thousands of units using separate MeshInstance3D nodes; strictly use `MultiMeshInstance` with `INSTANCE_CUSTOM` data to drive unique GPU-side state animations (walking/attacking/color).
• NEVER calculate transforms for mass units on the main thread; strictly use `WorkerThreadPool` to push buffers to RenderingServer.multimesh_set_buffer().
• NEVER update every unit's navigation path in the same frame; strictly use random timers to stagger updates.
• NEVER use standard Strings for high-frequency AI state identifiers; strictly use StringName (&"harvesting") for pointer-speed comparisons.
• NEVER allow simulation coordinates to exceed 8192 units without float-precision management; strictly use world-origin shifts.
• NEVER use CSGShape3D for building placement ghosts; strictly use optimized static ArrayMesh geometry.

🛠 Expert Components (scripts/)

MANDATORY: Read the script for the workflow you are implementing — do not re-inline selection/fog recipes in the agent body.

Selection / commands

• selection_manager_marquee_2d.gd — MANDATORY for 2D drag-box, filter, shift-add.
• selection_manager_raycast_3d.gd — MANDATORY for 3D PhysicsServer picks.
• rts_selection_overlay.gd — Selection visuals / box overlay.
• rts_group_commander.gd — SceneTree group broadcast for mass orders.
• rts_targeting_logic.gd — Distance-squared enemy filtering.

Units / navigation / army

• rts_unit.gd — MANDATORY unit controller (states + NavigationAgent).
• crowd_navigation_unit.gd — RVO / crowd agent wiring.
• rts_path_query_pool.gd — Pooled Navigation path queries.
• navigation_mask_helper.gd — Nav layers / avoidance bitmasks.
• rts_army_manager.gd — WorkerThreadPool army AI batches.
• rts_unit_stat_duplicator.gd — duplicate_deep() isolation for unit Resources.

Economy / build / fog / ghosts

• global_economy_manager.gd — Gather/spend bank Autoload pattern.
• building_grid_astar.gd — Grid placement pathing.
• fog_of_war_tile_mask.gd — MANDATORY TileMapLayer fog clear (2D/grid).
• rendering_ghost_spawner.gd — Placement ghosts via RenderingServer RIDs.
• rts_formation_manager.gd — Center-of-mass group path + per-unit formation offsets.
• rts_massive_unit_renderer.gd — MultiMeshInstance3D army renderer synced from unit transforms.

Core Loop

1. Gather: Units collect resources (Gold, Wood, etc.).
2. Build: Construct base buildings to unlock tech/units.
3. Train: Produce an army of diverse units.
4. Command: Micromanage units in real-time battles.
5. Expand: Secure map control and resources.

Skill Chain

Decision Tree: NavigationAgent+RVO vs MultiMesh+server sim

Rule: Keep NavigationAgent+RVO while units need individual collision avoidance and micromanage feel. Switch to MultiMesh + server-side transforms when draw-call/node cost dominates — path as squads, not as thousands of agents.

Architecture Overview

1. Selection Manager

MANDATORY: selection_manager_marquee_2d.gd (2D) or selection_manager_raycast_3d.gd (3D). Maintain a typed selection set (not SceneTree-only) for netcode/save. Overlay: rts_selection_overlay.gd.

2. Unit Controller (State Machine)

MANDATORY: rts_unit.gd for Idle/Move/Attack/Hold + NavigationAgent. Deep state graphs → godot-state-machine-advanced. Always duplicate_deep() shared stat Resources (rts_unit_stat_duplicator.gd).

3. Group Movement & Formations

Avoid clumping on one click target: compute center of mass, apply relative offsets, issue per-unit destinations. For hundreds of units, use one NavigationServer path for the COM (Batch 09) plus rts_group_commander.gd / rts_path_query_pool.gd.

4. Fog of War

MANDATORY for tile/grid fog: fog_of_war_tile_mask.gd. SubViewport mask + shader overlay is valid for soft vision — implement via docs (Using Viewports) + godot-shaders-basics; Do NOT paste long fog shaders into this skill body when the tile-mask script covers the grid path.

Key Mechanics Implementation

Command Queue

Shift-click chains: store Array of serializable commands; pop on finish; draw queued path lines. Pair with selection scripts' issue-command hooks.

Resource Gathering

ResourceNode → work timer → DropoffPoint → bank update. Wire bank through global_economy_manager.gd / godot-economy-system.

Common Pitfalls

1. Pathfinding jitter — Enable RVO; call set_velocity + move on velocity_computed; stagger group path queries.
2. Too much micro — Auto-aggro / auto-return gather; command queue for force-move/attack.
3. Node explosion — Past a few hundred units, follow the decision tree (MultiMesh + army manager), not per-unit _process.

Godot-Specific Tips

• Avoidance: NavigationAgent* RVO requires set_velocity() + velocity_computed for the actual move.
• Server architecture: Central UnitManager / rts_army_manager.gd for 100+ units.
• Groups: Units, Buildings, Resources for selection filters.

🚀 Elite Technical Implementations (Batch 09)

1. Center-of-Mass Formation Movement

For large selections, one NavigationServer path from COM → target, then offset each unit (see decision tree). Keep the algorithm in project code or formation helpers; pair with rts_path_query_pool.gd so path objects are pooled.

# Sketch only — prefer pooled queries from rts_path_query_pool.gd
static func move_group_to_target(units: Array, target: Vector3, map_rid: RID) -> void:
    if units.is_empty():
        return
    var com := Vector3.ZERO
    for u in units:
        com += u.global_position
    com /= units.size()
    var path: PackedVector3Array = NavigationServer3D.map_get_path(map_rid, com, target, true)
    if path.is_empty():
        return
    var dest: Vector3 = path[path.size() - 1]
    for u in units:
        u.set_movement_target(dest + (u.global_position - com))

2. MultiMesh armies (when decision tree says so)

Pre-allocate instance_count, drive visible_instance_count, push transforms (optionally via WorkerThreadPool → RenderingServer.multimesh_set_buffer). No per-soldier MeshInstance3D. See Official Documentation → Using MultiMesh.

3. Fog — script first

Prefer fog_of_war_tile_mask.gd. SubViewport vision masks: docs + godot-shaders-basics (do not duplicate long shader bodies here).

MANDATORY for depth beyond decision trees and script catalog: rts-mass-army-deep.md. Do NOT Load on first-pass wiring — use bundled scripts/ first.

Reference

Progressive disclosure: open Official Documentation links only when researching a specific API;

load Related Skills when routing work to a peer domain — do not preload the whole lattice.

Official Documentation

• Navigation (tutorial index) — Entry map for agents, servers, meshes, layers, and obstacles before wiring army movement.
• Using NavigationAgents — set_velocity / velocity_computed RVO loop that stops crowd jitter and stuck IDLE timeouts.
• Using NavigationServers — Direct map path queries for center-of-mass formation moves without per-unit agent spam.
• Using navigation path query objects — Pooled NavigationPathQueryParameters* patterns for mass move orders without heap churn.
• Optimizing navigation performance — Staggered queries, avoidance budgets, and obstacle swaps when hundreds of units path each tick.
• Using MultiMesh — GPU instance buffers for thousands of units instead of one MeshInstance per soldier.
• Using multiple threads — WorkerThreadPool contracts for army AI batches off the main thread.
• Ray-casting — Direct space-state picks for 3D selection and ground click targeting.
• Using Viewports — SubViewport vision masks that feed fog-of-war shaders without CPU tile floods.
• Mouse and input coordinates — Screen-to-world mapping for marquee boxes, unproject selection, and shift-queued orders.
• AStarGrid2D — Fast grid pathing for building footprints and base placement checks.
• Resources — Why unit stats must duplicate(true) so health/armor never mutate a shared template.

Related Skills

Prerequisites

• godot-project-foundations — Physics ticks, navigation/avoidance project settings, and input map actions before selection and pathing stay deterministic.
• godot-input-handling — Mouse buttons, shift-modifiers, and physics-step sampling that drive marquee select and command queuing.
• godot-navigation-pathfinding — NavigationAgent RVO, maps, layers, and query-object pools this genre's army movement builds on.

Complements

• godot-camera-systems — RTS pan/zoom/edge-scroll framing so selection and orders stay readable at strategic scale.
• godot-raycasting-queries — PhysicsServer ray/shape recipes for 3D picks under heavy unit counts.
• godot-state-machine-advanced — Idle/Move/Attack/Hold command states and queue transitions per unit without spaghetti flags.
• godot-shaders-basics — CanvasItem/spatial mask shaders that sample SubViewport fog textures.
• godot-autoload-architecture — Global economy and army managers as Autoloads with clear boot order.
• godot-economy-system — Gather/spend ledgers and cost dictionaries the RTS bank Autoload should reuse.
• godot-signal-architecture — Group broadcast and command buses so commanders never hard-iterate every unit node.

Downstream / consumers

• godot-monte-carlo-balancer — Build-order policies, unit cost curves, and AI opponent strength — simulate win% instead of gut-tuning gather rates.
• godot-performance-optimization — Escalate here when MultiMesh buffers, avoidance, or WorkerThreadPool still dominate the profiler.
• godot-combat-system — Hit/hurt and targeting contracts once move/attack commands need damage resolution.

Master

• godot-master — Library router and mirrored module entry; open when discovering which Domain Skill owns a cross-cutting RTS concern.