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 cell_size doesn't update existing tiles, causing misalignment. Set it once at the start.
NEVER use MeshLibrary without collision shapes — Items without collision spawn visual-only geometry that players fall through.
NEVER enable volumetric fog without DirectionalLight3D — Volumetric fog requires at least one light to scatter. No lights = no visible fog.
NEVER animate CSG nodes during gameplay — Moving a CSG node within another forces the CPU to recalculate the boolean geometry, causing significant performance drops.
NEVER place generic logic nodes in a GridMap — GridMap is highly optimized only for meshes, navigation, and collision. It is not a general-purpose system for placing arbitrary node structures on a grid.
NEVER use non-manifold meshes in CSG — If you import a custom mesh for CSGMesh3D, it must be manifold (closed, no self-intersections, no interior faces, no negative volume). Non-manifold meshes will break the CSG algorithm and are completely unsupported.