Nav Mesh

A Navigation Mesh (NavMesh or nav mesh) is a data structure that stores data used for path finding, which is typically used by bots. In Source, navigation meshes are used by the following entities:

1. Bots and Hostages in:
   • Counter-Strike: Source
   • Counter-Strike: Global Offensive
2. NextBot entities in:
   • Left 4 Dead
   • Left 4 Dead 2
   • Garry's Mod
   • Team Fortress 2
   • Postal III
   • Jabroni Brawl: Episode 3
   • Black Mesa

…to realize what's navigable in their environment, and path to their desired destination.

NAV file format

Main article:  .nav

NAV files

Navigation Mesh data is stored in a NAV file corresponding to the map file (.bsp) for which it is used. For example, the nav mesh for cstrike\maps\de_dust.bsp is stored in cstrike\maps\de_dust.nav.

Navigation Mesh Editing

Main article:  Nav Mesh Editing

Main article:  Nav Mesh Commands

The Navigation Mesh Editing is done in-game. A (new) .nav file can be generated with nav_generate (which requires sv_cheats 1 and nav_edit 1).

Game Specific SubVersions

Game	Nav Mesh Class	Subversion	Notes
Source Garry's Mod	TheNavMesh	0	Garry's Mod uses the base navigation mesh (It doesn't use its own implementation unlike Valve games)
Counter-Strike: Source Counter-Strike: Global Offensive	CSNavMesh	1	* Appends approach area data to each area.
Team Fortress 2	CTFNavMesh	2	Appends TF2-specific attribute flag to area data.
Left 4 Dead	TerrorNavMesh	13
Left 4 Dead 2	TerrorNavMesh	14

See also

• Navigation Mesh Console Command Reference
• List of L4D Series Nav Mesh Attributes
• L4D Level Design/Nav Meshes
• L4D Level Design/Nav Flow
• L4D Level Design/Advanced Nav Editing

External links

• Official forums for the bot system (down) - Archived version.
• Waypointing for CS:S Bots/Hostages (Edit Life)