L4D2 Level Design/Weapon and Item Spawning
Contents
Weapon placement capability in L4D2 maps has been expanded and enhanced. While you can still place specific weapon and item entities as in L4D1, the new weapon_spawn allows more flexibility by allowing the A.I. Director to procedurally generate your player's arsenal. Another benefit of using these new spawn entities is that they will provide matching items for both versus/scavenge teams.
Weapons inside saferooms will be carried over into the next map, relative to the info_landmark. Which means all the weapon spawns in the upcoming map will be deleted and replaced with whatever weapons and items were available in the previous map's end saferoom. This allows you to place weapon_spawn entities to randomize the appearing weapon and have the same weapon show up in the next saferoom.
This also means that you don't have to pay a lot of attention to having the guns be in the literal exact same spot for both saferooms. Because the only important part will be the info_landmark, which does the heavy lifting for you.
Placing Weapon Spawners
Activate the the Entity tool 
and select the weapon_spawn entity from the Objects drop-down menu.
This entity is a random spawn point for a set of possible weapons based on tier or weapon type.
The Director will randomly pick which weapon_spawn and weapon_item_spawn should be spawned. Sometimes nothing will spawn. The info_map_parameters entity can be used to determine how the map should be populated with items, when used in conjunction with the console command, director_solve_item_density x.
Using the 3D view, navigate to the starting area in the map and click to place a weapon spawn on the table. You should see an older weapon spawn in the instance. Just place it next to it.
Although it appears in the Hammer viewport as an M16 rifle for placement purposes, what it spawns during gameplay will vary.
You can add a "Helper Model" to the entity, to pick what model you want to see. This can be achieved by editing the FGD file, as explained in this Steam Guide
Let's restrict this weapon spawn to tier 1 primary, so we can save tier 2 for later in the map. With the recently placed weapon_spawn entity selected, open the Properties window and click on the Selection field. From the drop down menu, select "Any tier 1 primary".
As you can see from the drop-down, you can similarly limit it to a certain type of weapon, such as any shotgun, any pistol, etc.
Direct Weapon Spawners
If you are building a survival map in which weapon_spawn and weapon_item_spawn does not work, you can determine a specific weapon to always spawn in the same spot using the following entities:
Note:These work on default maps as well, but the Director will not decide whether to spawn them or not.- weapon_autoshotgun_spawn
- weapon_grenade_launcher_spawn
- weapon_hunting_rifle_spawn
- weapon_pistol_magnum_spawn
- weapon_pistol_spawn
- weapon_pumpshotgun_spawn
- weapon_rifle_ak47_spawn
- weapon_rifle_desert_spawn
- weapon_rifle_m60_spawn
- weapon_rifle_sg552_spawn
- weapon_rifle_spawn
- weapon_shotgun_chrome_spawn
- weapon_shotgun_spas_spawn
- weapon_smg_mp5_spawn
- weapon_smg_silenced_spawn
- weapon_smg_spawn
- weapon_sniper_awp_spawn
- weapon_sniper_military_spawn
- weapon_sniper_scout_spawn
Mounted weapons
Mounted guns are also available, which overheat when used for too long. They are usually placed in fortified locations such as Finales or abandoned military outposts.
The minigun overheats after 20 seconds and cools down for 3 seconds. The machine gun takes 15 seconds to overheat and 60 seconds to cool down.
Melee weapons
Placing melee weapons procedurally works in much the same way using the weapon_melee_spawn entity. Go ahead and place one of these and open up the Properties dialog.
The weapons that you want to allow to spawn at this location have to be included in the text field. Names include:
Any– director will place any melee weapon listed in the Missionfile's "meleeweapons" string.baseball_batcricket_batcrowbarelectric_guitarfireaxefrying_pangolfclubkatanaknifemachetepitchforkshoveltonfa
You may also list multiple specific melee weapons separated by a comma, and the director will select from among that subset of weapons:
crowbar,fireaxe,machete
You may even have additional custom melee weapons by crating a working weapon model and then creating a melee weapon script in "scripts/melee". Copy an existing one as a base and modify it to make it easier for you.
The name of that script, without extension, is the name to use in the missionfile to allow it at all, and the weapon_melee_spawn entity.
Item spawning
Item spawning works in much the same way, with weapon_item_spawn providing a way to spawn any one of a set of items. Let's go ahead and add a couple to the arsenal on the table.
Under Properties, you can specify the items that you wish to allow by changing their value to 1.
Similarly, laser sights and ammo upgrade packs are placed using the upgrade_spawn entity.
Predetermined Item Spawners
For Predetermined item spawn points, use the following entities.
- weapon_adrenaline_spawn
- weapon_ammo_spawn
- weapon_chainsaw_spawn
- weapon_defibrillator_spawn
- weapon_first_aid_kit_spawn
- weapon_gascan_spawn
- weapon_item_spawn
- weapon_melee_spawn
- weapon_molotov_spawn
- weapon_pain_pills_spawn
- weapon_pipe_bomb_spawn
- weapon_scavenge_item_spawn
- weapon_upgradepack_explosive_spawn
- weapon_upgradepack_incendiary_spawn
- weapon_vomitjar_spawn
The following items require FGD file edits to use properly. How to do so can be found on this Steam Guide
- upgrade_ammo_explosive - Deployed explosive ammunition.
- upgrade_ammo_incendiary - Deployed incendiary ammunition.
- upgrade_laser_sight - laser sight box.
Carryable Objects
Although Oxygen Tanks, Propane Tanks and Firework Crates have their own entities, they're spawned as Prop_physics instead.
Place a Prop_physics entity into your map and use any of the following models to spawn their carryable counterpart:
- models/props_junk/propanecanister001a.mdl
- models/props_junk/explosive_box001.mdl
- models/props_equipment/oxygentank01.mdl
Gascans can be spawned using weapon_gascan_spawn
Test run
Go ahead and run your map. Each time you reload it, you should see a different collections of weapons, with the exception of the L4D1 shotgun in the original instance. That will remain the same since it is a weapon_pumpshotgun_spawn.
Note: If you want to have that older weapon_pumpshotgun_spawn not appear in the Left 4 Dead 2 version of the map, but still want to keep it in the .VMF, you can create a logic_auto in the L4D2 .VMF and have it kill the pump shotgun.