Weapon physcannon

Class hierarchy
CWeaponPhysCannon ↳CBaseHL2MPCombatWeapon ↳CWeaponHL2MPBase ↳CBaseCombatWeapon ↳CBaseAnimating ↳CBaseEntity
weapon_physcannon.cpp

weapon_physcannon is a model entity available in Half-Life 2 series and Portal.

It's the Zero-Point Energy Field Manipulator (AKA Gravity Gun), used to manipulate physics objects in the game world. Before it is picked up, the gravity gun also follows all physics rules as if it were a prop_physics.

The Zero-Point Energy Field Manipulator was designed for handling hazardous materials, but the people at Eli's lab mainly used it for heavy lifting.

It does not require any ammunition or recharging. Special interactions between a physics prop and the gravity gun are defined by the physgun_interactions in the model's QC file.

Gravity Gun has two attacks: punt and grab. Primary attack emits a charge, making props fly. Secondary attack attracts prop to the gun and grabs it. In this state, primary attack throws the prop, secondary attack releases it.

The effective range of each attack depends largely on the mass of the prop. Some NPCs (antlions and headcrabs) are pushed back by the impact of a punt at close range.

Tip:To supercharge the Gravity Gun, use an env_global entity to enable the global state super_phys_gun. This does not work in Half-Life 2: Deathmatch nor Portal.

Bug:Sometimes the game may crash when the player is holding something at the moment they pick up the gravity gun.  [todo tested in ?]

Games

Half-Life 2

Player obtains the Gravity Gun given by Alyx on d1_eli_02 (Black Mesa East).

Half-Life 2: Episode One and Half-Life 2: Episode Two

On the beginning of both Half-Life 2: Episode One and Half-Life 2: Episode Two, player obtains the Gravity Gun given by Dog on ep1_citadel_00 (Undue Alarm, EP1), and Alyx on ep2_outland_01 (To The White Forest, EP2).

Players spawn with a Gravity Gun on all maps after the beginning of both Episode One and Two.

Half-Life 2: Deathmatch

Players spawn with a Gravity Gun by default.

Portal

Only available if placed in a custom map or using a cheat such as impulse 101 or give weapon_physcannon.

KeyValues

Name (targetname) <string>[ Edit ]

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

Flags

Start Constrained : [1]

Prevents the model from moving. Off by default.

Start without grab functionality. : [2] (removed since )

Deny player pickup (reserve for NPC) : [2] (in all games since )

Not puntable by Gravity Gun : [4] (in all games since )

Inputs

EnableGrab

Enable the grab functionality. Obsolete (in all games since )

HideWeapon  !FGD

If this weapon is being held, hide the worldmodel and/or viewmodel via EF_NODRAW. Weapon will still be useable. The weapon will become visible again if the holder is to switch between weapons in their inventory.

Outputs

Weapon:

OnNPCPickup

!activator = NPC
!caller = this entity
Fires when an NPC picks up this weapon.

OnPlayerUse

!activator = player
!caller = this entity
Fires when the player +uses this weapon.

OnPlayerPickup

!activator = player
!caller = this entity
Fires when a player picks up this weapon.

OnCacheInteraction

Fires when the player 'proves' they've found this weapon. Fires on: Player Touch, +USE pickup, Physcannon pickup, Physcannon punt.

Dedicated console variables

Cvar/Command	Parameters or default value	Descriptor	Effect
g_debug_physcannon	0	bool	Enables Gravity Gun debugging, which shows a wireframe outline around objects when picked up
physcannon_ball_cone	0.997	float	The dot product of the search cone when using the charged Gravity Gun; if it detects a Prop combine ball within this cone, it'll prioritize picking it up
physcannon_chargetime	2	float	Todo: Add a description for this variable.
physcannon_cone	0.97	float	Changes how wide the pickup range is, lower numbers are wider. This is a dot product value
physcannon_dmg_glass	15	float	Todo: Add a description for this variable.
physcannon_maxforce	1500.0	float	Todo: Add a description for this variable.
physcannon_maxmass	250.0	float	Sets the maximum mass at which an object can be picked up by the gravity gun
physcannon_mega_enabled	0	bool	Enables Dark Energy Field Manipulator Code Fix:Half-Life 2: Deathmatch Zero Point Energy Field Manipulator fix.
physcannon_mega_pullforce	8000.0	float	How much force used by Dark Energy Field Manipulator to pull objects to player.
physcannon_mega_tracelength	850.0	float	The distance at which the Dark Energy Field Manipulator will be able to pull an object
physcannon_minforce	700.0	float	Todo: Add a description for this variable.
physcannon_pullforce	4000.0	float	How much force to be used when pulling objects to the player
physcannon_punt_cone	0.997	float	Todo: Add a description for this variable.
physcannon_right_turrets	0	float	Todo: Add a description for this variable.
physcannon_tracelength	250.0	float	How far an object can be pulled from

Console commands

Cvar/Command	Parameters or default value	Descriptor	Effect
phys_swap			Swaps between gravity gun and the most recently-used weapon. Bound to 'g' by default.

See Also

• Half-Life 2: Deathmatch Zero Point Energy Field Manipulator fix