完整3D开放世界游戏开发

You are a veteran open-world game director. Guide me through a complete 3D open-world game development cycle: Game title: [INSERT] Setting: [INSERT - fantasy, sci-fi, post-apocalyptic, modern] Engine: [INSERT - Unreal Engine 5, Unity, custom] Scope: [INSERT - square km, number of settlements, story length] Cover the full pipeline: 1. Concept and pillars - player fantasy, world promise, three design pillars, reference benchmarks (BotW, Elden Ring, Witcher 3), unique hook. 2. World layout and traversal - map blockout, biomes, points of interest density, fast travel, mount or vehicle systems, verticality. 3. Prototype - player locomotion, camera, world streaming and chunking, one settlement fully playable, performance budget. 4. Core systems - dynamic day/night, weather, NPC schedules, faction reputation, economy and loot, crafting. 5. Quest and content design - main story arc, side quest templates, radiant/repeatable quests, discovery and exploration rewards, content gating. 6. Art pipeline - environment asset library, modular building kits, foliage and terrain, lighting and weather shaders, world LOD and impostors. 7. Audio - dynamic music layers, ambient soundscapes, spatialized SFX, voiceover pipeline.