Why does my Godot navigation bake miss part of the level?

NavigationPolygon's Parse Mode determines what geometry is included. Default is StaticBody2D children — if your walls are TileMap or CollisionPolygon2D under a different parent, they're not parsed. Set Parse Mode to Both Types and add walls to the Source Group.

How do I bake at runtime after dynamic changes?

NavigationServer2D.region_bake_navigation_polygon(region_rid). Or NavigationRegion2D.bake_navigation_polygon(true) which is a thin wrapper. Bakes synchronously by default; pass async = true for a threaded bake when level pieces stream.

Why are agents walking through walls?

Bake source includes don't include the walls, so the navmesh covers the whole level including 'inside' walls. Add the wall colliders to the parsing group, or use NavigationObstacle2D nodes to carve out forbidden regions on top of the bake.

Fix: Godot 4 NavigationRegion2D Bake Skipping Polygons

Quick answer: Open the NavigationPolygon resource on the region. Set Parse Geometry → Source Group, then add your wall nodes to that group. Bake. The bake now sees walls regardless of where they live in the tree.

You bake a NavigationRegion2D and half your dungeon’s walls are ignored. Agents walk diagonally through stone. The bake source isn’t finding the wall colliders because they’re not where the parser is looking.

The Symptom

Bake produces a navmesh that ignores some walls (often TileMap-based ones). Or the navmesh covers regions that should be impassable. Agents path through walls.

The Mental Model

NavigationRegion2D bakes a NavigationPolygon resource. The polygon’s Geometry section configures:

Parsed Geometry Type — Mesh Instances, Static Colliders, or Both.
Source Geometry Mode — Root Node Children, Group With Children, or Group Explicit.
Source Group Name — for Group modes, the group whose nodes contribute geometry.

Default Source Geometry Mode = Root Node Children only finds direct children of the NavigationRegion2D. If your walls are nested elsewhere, they’re invisible to the bake.

The Fix

Step 1: Set Source Geometry Mode = Group With Children. Open the NavigationPolygon. Geometry → Source Geometry Mode → Group With Children. Name the group “navmesh_source.”

Step 2: Add wall nodes to the group. Select your wall TileMap or StaticBody2D. Inspector → Node tab → Groups → Add “navmesh_source.”

Step 3: Set Parsed Geometry Type to Both. Some walls are colliders, some are mesh outlines. Both Types covers all bases.

Step 4: Bake. Click NavigationRegion2D in scene tree. Click the “Bake NavigationPolygon” button in the inspector preview. The polygon updates to enclose the walkable area, with walls excluded.

Runtime Bake

extends NavigationRegion2D

func rebake_for_destruction(broken_wall: Node2D) -> void:
    broken_wall.queue_free()
    await get_tree().process_frame
    bake_navigation_polygon(true)   # async

For dynamically changing levels, rebake after the change. Async bake doesn’t block the main thread.

NavigationObstacle2D for Dynamic Carve

For obstacles that move at runtime (a moving block, a temporarily-locked door), use NavigationObstacle2D instead of rebaking. The obstacle creates a runtime hole in the navmesh that agents avoid without re-baking.

Verifying

Project Settings → Debug → Settings → Visible Navigation. Reload the scene. The navmesh renders as a colored polygon. Walk the camera; navmesh should follow walkable area, miss walls. If walls appear inside, the source group doesn’t include them.

“Group source. Both types. Bake. Walls become walls.”

Related Issues

For NavigationAgent2D not pathing, see agent not pathing. For dynamic obstacle, see obstacle blocking.

Source group. Bake. The pathfinding sees the level.