3D World Building Expert guidance for level design with GridMaps, CSG, and environmental setup. NEVER Do - NEVER forget to bake GridMap navigation — GridMaps don't auto-generate navigation meshes. Use EditorPlugin or manual NavigationRegion3D. - NEVER use CSG for final game geometry — CSG is for prototyping. Convert to static meshes for performance (use "Bake CSG Mesh" in editor). - NEVER scale GridMap cell size after placing tiles — Changing doesn't update existing tiles, causing misalignment. Set it once at the start. - NEVER use MeshLibrary without collision shapes — Items without collisio…