What's a MeshLibrary?

Godot’s tileset for GridMap. Each entry is a mesh plus optional collision and navigation data, indexed by ID. GridMap places these at integer cell positions.

Why is collision missing?

MeshLibrary only bakes collision from StaticBody3D + CollisionShape3D nodes under each mesh in the source scene. A bare MeshInstance3D gets no collision in the library, even if it visually shows.

How do I add collision quickly?

Right-click a MeshInstance3D → Mesh menu → Create Single Convex Collision Sibling. Wraps the mesh in StaticBody3D + matching CollisionShape3D. Then export to MeshLibrary.

Fix: Godot MeshLibrary Physics Shape Not Baked

Quick answer: Add a StaticBody3D + CollisionShape3D under each MeshInstance3D in the source scene, then re-export via Scene → Export As → MeshLibrary.

A dungeon prototype uses GridMap to lay out walls and floors. Player walks straight through every wall. MeshLibrary built fine, meshes render, but no collision — collision wasn’t baked.

Source Scene Layout

Each cell in the library comes from a top-level node in the source scene. For collision to bake, that node needs the right structure:

WallTile (Node3D)
  - MeshInstance3D
  - StaticBody3D
      - CollisionShape3D

The MeshLibrary exporter walks each top-level node looking for these children.

Quick Way: Auto-Generate Collision

For each mesh:

Click the MeshInstance3D in the source scene.
Top toolbar: Mesh → Create Single Convex Collision Sibling.
For walls/floors: Trimesh Static Body for accurate shape.

Godot creates the matching StaticBody3D and CollisionShape3D automatically.

Re-export

Open the source scene. Scene → Export As → MeshLibrary. Pick the existing .meshlib path; overwrite. GridMap auto-refreshes the next time you open it.

Common Pitfalls

Wrong physics body type: only StaticBody3D bakes; CharacterBody3D, RigidBody3D etc. are ignored.
Disabled CollisionShape: disabled = true still exports as disabled. Verify enabled before export.
Bad transforms: rotated/scaled nodes can bake collision in a different pose than the mesh visually shows.

Verifying

Run scene. Walk toward a wall — player stops. Open Editor Debugger → Visible Collision Shapes; shapes should match wall meshes 1:1.

“MeshLibrary is a flat archive. What you put in the source scene is what bakes. Add StaticBody3D children for every collidable.”

For NavigationRegion3D tiles, the same scheme applies but with NavigationMesh + Navigation Region children. Bake nav and physics together for grid-based dungeons.