UE5-Modular-Game-Framework/docs/developer/INDEX.md

Developer Reference — UE5 Modular Game Framework

Version: 1.6 | Generated: 2026-05-22 | Files: 19 (1 index + 2 overview + 1 migration + 1 integration + 1 prototype + 1 starter + 10 category docs + 1 combined + 1 capture) | C++: 15 full + 10 stubs = 25 systems

This directory contains developer-facing reference documentation for every system in the framework. Unlike the blueprint spec files (which define what to build), these documents explain how each system works internally — the data flow, state machines, integration points, and design rationale. Use these when you need to understand a system's behavior to implement, debug, or extend it.

Who This Is For

• Blueprint implementers turning .md specs into actual UE5 Blueprint assets
• Debuggers tracing why something doesn't work
• Designers needing to understand constraints before modifying Data Assets
• New team members learning the framework's internal logic

Directory Map

docs/developer/
├── INDEX.md                              ← THIS FILE
├── architecture-overview.md              ← Framework-wide architecture walkthrough
├── implementation-patterns.md            ← Common UE5 Blueprint patterns used
├── cpp-integration-guide.md              ← C++ per-system integration & setup (22 systems)
├── project-setup-migration.md            ← Project setup & migration guide
├── project-prototype-guide.md            ← Step-by-step prototype build guide (NEW)
├── 00-starter-gameinstance.md            ← Starter GameInstance: GI_StarterGameInstance setup guide
├── 01-core-foundation.md                 ← Foundation systems explained
├── 02-player-systems.md                  ← Player state & embodiment (systems 08-15)
├── 03-interaction-systems.md             ← Interaction & world manipulation (systems 16-23)
├── 04-inventory-systems.md               ← Inventory, items & collectibles (systems 24-34)
├── 05-saveload-systems.md                ← Save/load, persistence, death loop (systems 35-43)
├── 06-ui-systems.md                      ← UI, menus & diegetic presentation (systems 44-57)
├── 07-narrative-systems.md               ← Narrative, dialogue, objectives (systems 58-68)
├── 08-weapons-systems.md                 ← Weapons, equipment & damage (systems 69-79)
├── 09-ai-systems.md                      ← AI, perception & encounters (systems 80-88)
├── 10-adaptive-systems.md                ← Adaptive environment & atmosphere (systems 89-101, 132-133)
├── 11-16-systems.md                      ← Meta, Settings, Polish, Data Assets, Input, State (systems 102-135)
└── 17-capture-systems.md                 ← Planar Capture System — Mirrors, Portals, Monitors, Horror (systems 136-147)

Quick Reference — Every System at a Glance

#	System	Category	Role
—	GI_StarterGameInstance	Project Setup	Minimal GameInstance; tag validation entry point
01	DA_GameTagRegistry	Foundation	Central GameplayTag → asset registry
02	FL_GameUtilities	Foundation	Shared utility functions (logging, math)
03	I_InterfaceLibrary	Foundation	All framework interfaces
04	GI_GameFramework	Foundation	Application kernel; owns subsystems
05	GM_CoreGameMode	Foundation	Spawns player, manages game rules
06	GS_CoreGameState	Foundation	Shared game state, phase tracker
07	DA_ItemData	Foundation	Base item data asset
08	BPC_HealthSystem	Player	Health, damage, death trigger
09	BPC_StaminaSystem	Player	Stamina pool, sprint drain, exhaustion
10	BPC_StressSystem	Player	Psychological stress tiers, hallucinations
11	BPC_MovementStateSystem	Player	Movement mode + posture, GASP liaison
12	BPC_HidingSystem	Player	Hide/peek/breath-hold, LOS checks
13	BPC_EmbodimentSystem	Player	First-person body, arm IK, overlays
14	BPC_CameraStateLayer	Player	Camera FOV/offset per state
15	BPC_PlayerMetricsTracker	Player	Player metrics: accuracy, deaths, ratios
16	BPC_InteractionDetector	Interaction	Raycast interaction detection
17	I_HidingSpot	Interaction	Interface for hideable objects
18	BPC_DiegeticDisplay	Interaction	In-world screens (wristwatch, monitors)
19	BP_DoorActor	Interaction	Physical door with state machine
20	BP_PuzzleDeviceActor	Interaction	Puzzle device base actor
21	BPC_ContextualTraversalSystem	Interaction	Vault/mantle/slide/squeeze/climb
22	BPC_PhysicsDragSystem	Interaction	Grab/drag/release physics objects
23	BPC_UsableWorldObjectSystem	Interaction	Generic world object use (levers, buttons)
24	BPC_ContainerInventory	Inventory	World container inventory
25	BP_ItemPickup	Inventory	Physical item pickup in world
26	BPC_ActiveItemSystem	Inventory	Quick-slot item management
27	BPC_CollectibleTracker	Inventory	Collectible tracking, set bonuses
28	BPC_ConsumableSystem	Inventory	Consumable use (health packs, syringes)
29	BPC_DocumentArchiveSystem	Inventory	Document/journal archive
30	BPC_EquipmentSlotSystem	Inventory	Equipment slots, equip/unequip
31	BPC_InventorySystem	Inventory	Core inventory grid
32	BPC_ItemCombineSystem	Inventory	Item combination crafting
33	BPC_JournalSystem	Inventory	Quest/objective journal
34	BPC_KeyItemSystem	Inventory	Key item tracking, use-on-target
35	SS_SaveManager	Save/Load	Save/load subsystem
36	I_Persistable	Save/Load	Persistence interface
37	BP_Checkpoint	Save/Load	Checkpoint actor
38	BPC_AltDeathSpaceSystem	Save/Load	Alternate death/void space
39	BPC_DeathHandlingSystem	Save/Load	Death orchestrator
40	BPC_PersistentCorpseSystem	Save/Load	Corpse persistence
41	BPC_PersistentWorldStateRecorder	Save/Load	World state change recording
42	BPC_PlayerRespawnSystem	Save/Load	Respawn logic
43	BPC_RunHistoryTracker	Save/Load	Run/session history
44	SS_UIManager	UI	UI subsystem, menu stack
45	WBP_AccessibilityUI	UI	Accessibility settings UI
46	WBP_DiegeticHUDFrame	UI	Diegetic in-world HUD frame
47	WBP_HUDController	UI	Root HUD widget
48	WBP_InteractionPromptDisplay	UI	Interaction prompt popup
49	WBP_InventoryMenu	UI	Inventory grid UI
50	WBP_JournalDocumentViewer	UI	Document/journal viewer
51	WBP_MainMenu	UI	Main menu
52	WBP_MenuFlowController	UI	Menu state machine
53	WBP_NotificationToast	UI	Toast notification
54	WBP_ObjectiveDisplay	UI	Active objective HUD element
55	WBP_PauseMenu	UI	Pause menu
56	WBP_ScreenEffectController	UI	Full-screen effects
57	WBP_SettingsMenu	UI	Settings menu
58	BPC_NarrativeStateSystem	Narrative	Narrative state machine
59	BPC_ObjectiveSystem	Narrative	Objective tracker
60	BPC_DialoguePlaybackSystem	Narrative	Dialogue playback
61	BPC_DialogueChoiceSystem	Narrative	Dialogue choices
62	BPC_BranchingConsequenceSystem	Narrative	Consequence execution
63	BPC_TrialScenarioSystem	Narrative	Timed trial/puzzle scenario
64	BPC_CutsceneBridge	Narrative	Cutscene bridge
65	BPC_LoreUnlockSystem	Narrative	Lore/journal unlock
66	DA_NarrativeDataAssets	Narrative	Narrative data assets
67	BP_NarrativeTriggerVolume	Narrative	Narrative trigger volume
68	BPC_EndingAccumulator	Narrative	Ending condition tracker
69	BP_WeaponBase	Weapons	Weapon base actor
70	BPC_AmmoComponent	Weapons	Ammo pool
71	BPC_CombatFeedbackComponent	Weapons	Combat feedback (hit markers)
72	BPC_DamageReceptionSystem	Weapons	Damage reception/resistance
73	BPC_DeathCauseTracker	Weapons	Death cause logging
74	BPC_FirearmSystem	Weapons	Firearm specialization
75	BPC_HitReactionSystem	Weapons	Hit reaction animations
76	BPC_MeleeSystem	Weapons	Melee weapon system
77	BPC_RecoilSystem	Weapons	Recoil pattern
78	BPC_ReloadSystem	Weapons	Reload system
79	BPC_ShieldDefenseSystem	Weapons	Shield defense
80	BP_EnemyBase	AI	Enemy base character
81	BP_PatrolPath	AI	Patrol path spline
82	BPC_AlertSystem	AI	AI alert states
83	BPC_AIStateMachine	AI	AI state machine
84	AI_BaseAgentController	AI	Base AI controller
85	BB_AgentBoard	AI	AI blackboard definition
86	BPC_AIMemorySystem	AI	AI memory/last known locations
87	BPC_AIPerceptionSystem	AI	AI perception (sight/hearing)
88	BPC_BehaviourVariantSelector	AI	Behavior variant selection
89	BPC_DifficultyManager	Adaptive	Dynamic difficulty scaling
90	BPC_FearSystem	Adaptive	Fear system (AI + player)
91	BPC_PerformanceScaler	Adaptive	Performance scaling (LOD)
92	BPC_ProceduralEncounter	Adaptive	Procedural encounter generation
93	BPC_AdaptiveEnvironmentDirector	Adaptive	Adaptive environment director
94	BPC_AtmosphereStateController	Adaptive	Atmosphere state (tone, tension)
95	BPC_AudioAtmosphereController	Adaptive	Audio atmosphere [DEPRECATED]
96	BPC_LightEventController	Adaptive	Light events (flicker/strobe)
97	BPC_MemoryDriftSystem	Adaptive	Memory drift distortions
98	BPC_PacingDirector	Adaptive	Pacing director
99	BPC_PlaystyleClassifier	Adaptive	Playstyle classification
100	BPC_RareEventSystem	Adaptive	Rare event system
101	BPC_ScareEventSystem	Adaptive	Scare event system
102	BPC_ProgressStatTracker	Meta	Progress statistics
103	SS_AchievementSystem	Meta	Achievement subsystem
104	BPC_AccessibilitySettings	Settings	Accessibility settings
105	SS_SettingsSystem	Settings	Persistent settings subsystem
106	BPC_AnalyticsTracker	Polish	Analytics/telemetry
107	BPC_DevCheatManager	Polish	Developer cheats
108	BPC_ErrorHandler	Polish	Error/crash handling
109	BPC_FPSCounter	Polish	FPS counter
110	BPC_LoadingScreen	Polish	Loading screen
111	BPC_TutorialSystem	Polish	Tutorial system
112	WBP_CreditsScreen	Polish	Credits screen
113	WBP_DebugMenu	Polish	Debug menu
114	WBP_SplashScreen	Polish	Splash screen
115	DA_AdaptationRule	Data Assets	Difficulty adaptation rules
116	DA_AtmosphereProfile	Data Assets	Atmosphere profile (audio/light/FX)
117	DA_BehaviourVariant	Data Assets	AI behavior variant
118	DA_DataAssetArchitecture	Data Assets	Data asset architecture overview
119	DA_EncounterData	Data Assets	Encounter definition
120	DA_EquipmentConfig	Data Assets	Equipment configuration
121	DA_HapticProfile	Data Assets	Haptic feedback profile
122	DA_InteractionData	Data Assets	Interaction definition
123	DA_ObjectiveData	Data Assets	Objective/quest data
124	DA_PuzzleData	Data Assets	Puzzle definition
125	DA_RareEvent	Data Assets	Rare event definition
126	DA_RoomMutation	Data Assets	Room mutation definition
127	DA_ScareEvent	Data Assets	Scare event definition
128	SS_EnhancedInputManager	Input	Enhanced Input manager
129	DA_InputMappingProfile	Data Assets	Input mapping profile per platform
130	BPC_StateManager	State	Central state authority
131	DA_StateGatingTable	State	State gating rules
132	SS_AudioManager	Adaptive	Audio subsystem (MetaSounds)
133	BP_RoomAudioZone	Adaptive	Room audio zone trigger
134	DA_AudioSettings	Data Assets	Audio bus/settings config
135	DA_RoomAcousticPreset	Data Assets	Room acoustic profile

How to Use These Docs

1. New to the framework? Start with architecture-overview.md to understand the big picture.
2. Setting up a new project? Read 00-starter-gameinstance.md first — create GI_StarterGameInstance to validate your GameplayTags immediately. Then follow project-setup-migration.md for full Project Settings, plugins, Data Tables, and init sequence.
3. Building a prototype? Follow project-prototype-guide.md — step-by-step instructions from blank project to working test character with verification checklist.
4. Using the C++ classes? Read cpp-integration-guide.md — per-system setup steps, Blueprint children to create, usage patterns, and build order. See ../checklists/cpp-blueprint-status.md for the full 135-system status grid.
5. Need the prioritized BP build list? See ../checklists/remaining-blueprint-build-order.md — every system with C++ status, what BP to build, and dependency-safe order.
6. Implementing a system? Read the Blueprint Spec in docs/blueprints/ — every file has a Manual Implementation Guide with node-by-node logic.
7. Need to understand internals? Read the corresponding Developer Reference doc in this directory.
8. Debugging? Each category doc includes a data flow section showing how data moves between systems.
9. Need UE5 Blueprint patterns? See implementation-patterns.md.
10. Multiplayer networking? See ../architecture/multiplayer-networking.md. Every doc has a Multiplayer Networking section.

Relationship to Spec Files

Aspect	Blueprint Spec (docs/blueprints/)	Developer Reference (docs/developer/)
Purpose	Define what to build with node-by-node logic (v2.0)	Explain how it works (understanding)
Audience	Implementers building Blueprints manually	Anyone needing to understand internals
Content	Enums, structs, variables, functions, Manual Implementation Guide	Data flow, state machines, design rationale
Format	TEMPLATE.md v2.0 — includes Build Checklist	Per-category reference docs + cpp-integration-guide + project-setup-migration

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Developer Reference Index v1.4 — Companion to the Blueprint Spec system. Update both together.