Your First Left 4 Dead Map

This article is currently a work in progress

This tutorial will cover the basics of Left 4 Dead map creation. It will explain the required entities, such as the director, weapons, and spawns. It will also answer some of the questions that Left 4 Dead mappers will have. This tutorial is not intended for new mappers: Basic level construction is already covered in other topics.

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Introduction sequences

• logic_choreographed_scene
• point_viewcontrol_survivor
• point_viewcontrol_multiplayer
• env_fade

Spawn area

• info_survivor_position
• weapon_first_aid_kit_spawn
• weapon_ammo_spawn
• weapon_smg_spawn
• weapon_pumpshotgun_spawn

The Director

Creating areas for the infected to spawn.

• info_director

The director will spawn infected that are out of the line of sight. Sometimes this is outside the normal player boundary. To let the infected into the playable area, there must be a func_simpleladder (with team set to 2) on the back side of the barrier, for them to climb over.

Item and weapon caches

Set spawn flags to randomize

• weapon_molotov_spawn
• weapon_pipe_bomb_spawn
• weapon_pistol_spawn
• weapon_pain_pills_spawn
• weapon_ammo_spawn
• weapon_smg_spawn
• weapon_first_aid_kit_spawn
• weapon_hunting_rifle_spawn
• weapon_rifle_spawn
• weapon_autoshotgun_spawn
• weapon_pumpshotgun_spawn

Rescue closets

Bringing dead players back into the game.

• prop_door_rotating
• info_survivor_rescue

Panic events

Triggering the info_director and summoning the horde.

• info_game_event_proxy
• ambient_generic
• logic_timer

• Examples
  • Car alarms
  • Metal detectors

Crescendo events

Intermediate objectives

• func_button
• filter_activator_team
• info_game_event_proxy

The safe house and changing levels

• prop_door_rotating_checkpoint
• info_landmark
• info_changelevel

Note:Make sure the info_landmark is named and that the landmark name is specified inside the info_changelevel settings along with a map name. Keep in mind the trigger_changelevel has to come in contact with the floor space inside the safe house due to how nav generation works. The trigger brush doesn't necessarily have to overlap the floor space, but it does have to at least touch it, or a good portion of where the nav square(s) will be generated. If the trigger_changelevel doesn't come in contact with the floor space, you will have nav errors when the map is loaded.

Building the navigation mesh

For survivor bots and infected to be able to move, you will need to create a navigation mesh ("mapname.nav" file) for your map. To build a basic mesh you need to have the map already compile and loaded, then open up the console in game and type the following:

sv_cheats 1

nav_edit 1

nav_mark_walkable

nav_generate

nav_analyze

nav_edit 0

sv_cheats 0

The map is reloaded twice during the process, once after nav_generate and again after nav_analyze, but the game should stay in edit mode when the map is reloaded.

Save fine tuning the mesh until after you are completely finished with the map's layout. The build sequence above should only be used for testing purposes. A nav mesh should be thoroughly examined and edited before releasing a map.

Note:For more information related to advanced mesh creation and editing, please refer to Navigation Meshes.

After a map is compiled and the nav mesh is built, sometimes the director still won't spawn infected after the map is loaded. To get around this you don't need a point_clientcommand or logic_auto inside the map to start/enable the director every time the map is loaded, all you have to do is load the map and, assuming you've built the nav mesh already and "sv_cheats" is set to 1, type "director_stop" then "director_start" (without the quotes). You only have to do this once inside the map, then every time you load the map after that the director should start on it's own.

Again, the console commands to kick start the director are:

sv_cheats 1

director_stop

director_start

sv_cheats 0

Finale

Ending the campaign.

Notes

Doors

Type: prop_door_rotating

Frame Dimensions: width: 56, height: 104

World Model: models/props_doors/doormainmetal01.mdl

FAQ

• How do I make the infected spawn?
  • Your map must have a info_director that is enabled, you also may have to use the console command "director_start".

• Why won't the survivor bots move?
  • The most likely cause is a faulty or missing ".nav" file. See Navigation Meshes

• Why is the molotov fire / Smoker's smoke cloud not visible in-game?
  • This is usually due to the lack of a env_fog_controller entity. You also want to make sure no errors were generated during the map's compile process.

• Why won't my rescue closets work?
  • Rescue closets will not function correctly if there are any nav errors present in the map. You will want to make sure Your nav mesh is properly set-up and you don't see the "NAV ERRORS - Map is unplayable!" message in game.

Error messages and what they mean

Navigation mesh related errors

These usually result with a message of "NAV ERRORS - Map is unplayable!" displayed in game when the map is loaded.

• Missing nav file.
• The nav file was built for an older compile.
• Missing Battlefield check found N areas
• GetGoalArea: Cannot find SPAWN_RESCUE_CLOSET area in FINALE, thus cannot guarantee reachability of goal area.
• GetGoalArea: Cannot find end area - no checkpoint or finale located.
• ComputeFlowDistances: ERROR - Cannot compute flow.

Note:To remove the "NAV ERRORS - Map is unplayable!" error message make sure your map has at least an info_player_start, info_director, prop_door_rotating_checkpoint, info_landmark, and an info_changelevel along with a working nav mesh.

Others

• WARN: CL4DBasePanel::UpdateProgressBar called outside of level loading, discarded!
• Engine Error: CModelLoader::FindModel: NULL name
  • This is caused by compiling the map using an outdated FGD which does not have the new values for the env_fog and light_environment. Therefore your compiling a BSP with missing information.
• Assert, File: U:\dev\terror\src\tier0\memstd.cpp, Line: 1623, Assert: ***** OUT OF MEMORY! attempted allocation size: 536873088 ****

See also

• Left 4 Dead Level Creation
• Navigation Meshes