View source for Collision groups

Collision groups define what types of collision can collide with each other. For example, an entity using <code>COLLISION_GROUP_DEBRIS</code> will only collide with the world and not any dynamic entities.

When the game tests a pair collision groups, the lower collision group is always first in the checks. All collision groups can touch triggers.

== List ==
These are defined in <code>public/const.h</code>:
{{todo|List collision groups and interactions from {{hl2}} and {{dods}}}}

{| class="standard-table"
|- style="z-index:1; position:sticky; top:0"
! width="100px" | Name
! width="50px" | Value
! width="75px" | Solid to players
! width="75px" | Solid to bullets
! width="75px" | Solid to projectiles
! width="75px" | Solid to physics
! width="75px" | Solid to world
! Description
|- id="none"
| <center>COLLISION_GROUP_NONE</center>
| <center>0</center>
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Default collision group
|- id="debris"
| <center>COLLISION_GROUP_DEBRIS</center>
| <center>1</center>
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
| Typically used for small objects that shouldn't interfere with gameplay. Will not touch triggers unless the trigger has the Debris spawnflag enabled. Collides with <code>COLLISION_GROUP_PUSHAWAY</code>.
|- id="trigger"
| <center>COLLISION_GROUP_DEBRIS_TRIGGER</center>
| <center>2</center>
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
| Despite the name, this is the same as <code>COLLISION_GROUP_DEBRIS</code>, but does not collide with <code>COLLISION_GROUP_PUSHAWAY</code>.
|- id="debris"
| <center>COLLISION_GROUP_INTERACTIVE_DEBRIS</center>
| <center>3</center>
| {{No|style=background:#FFFF00}}<br>{{hl2dm}} Yes
| {{No}}
| {{No}}
| {{No}}
| {{Yes}}
| Same as above, but doesn't collide with other <code>COLLISION_GROUP_INTERACTIVE_DEBRIS</code>. [[VPhysics]] props that are asleep will be converted to <code>COLLISION_GROUP_DEBRIS</code>
|- id="interactive"
| <center>COLLISION_GROUP_INTERACTIVE</center>
| <center>4</center>
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Does not collide with debris. [[$collisiontext|Gibs]] from models not flagged as debris are set to this group. [[func_door]] and [[func_door_rotating]] use this if set to ignore debris.
|- id="player"
| <center>COLLISION_GROUP_PLAYER</center>
| <center>5</center>
| {{Yes}}
| {{Yes}}
| {{Yes|style=background:#FFFF00}}<br>{{tf2}} Depends
| {{Yes}}
| {{Yes}}
| Used by players, but NOT for movement collision. Does not collide with <code>COLLISION_GROUP_PASSABLE_DOOR</code>.
Except in {{hl2dm}}, this will not collide with <code>COLLISION_GROUP_PUSHAWAY</code>. 

In {{tf2}}, does not collide with grenade, engineer buildings (except teleporters), combat object groups and tank groups.
|- id="glass"
| <center>COLLISION_GROUP_BREAKABLE_GLASS</center>
| <center>6</center>
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Used by [[func_breakable_surf]]. Does not collide with other <code>COLLISION_GROUP_BREAKABLE_GLASS</code>. NPCs ignore these for weapon [[LOS]] checks.
In {{hl2}}, crossbow bolts will go through this.
|- id="vehicle"
| <center>COLLISION_GROUP_VEHICLE</center>
| <center>7</center>
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Used by [[Half-Life_2_Vehicles|driveable vehicles]]. Always collides against <code>COLLISION_GROUP_VEHICLE_CLIP</code>
|- id="movement"
| <center>COLLISION_GROUP_PLAYER_MOVEMENT</center>
| <center>8</center>
| {{Yes|style=background:#FFFF00}}<br>{{tf2}} Depends
| {{Yes}}
| {{Yes|style=background:#FFFF00}}<br>{{tf2}} No
| {{Yes}}
| {{Yes}}
| Used by player movement collision tests.
{{hl2}} Behaves identically to <code>COLLISION_GROUP_PLAYER</code>. 
Except in {{hl2dm}}, this will not collide with <code>COLLISION_GROUP_PUSHAWAY</code>. 

In {{tf2}}, will not collide with projectile, rocket, grenade, combat object and tank groups. Engineer buildings (except teleporters), players (if <code>tf_avoidteammates</code> is 1), [[bot_npc_archer]], [[bot_npc_decoy]], [[func_croc]], [[func_forcefield]], [[func_respawnroom]], [[func_respawnroomvisualizer]], [[tf_target_dummy]] will check for team-specific [[$contents|contents]] (usually the entity's team number decide these) to consider collision. [[passtime_ball]] will not collide with this, but [[_ballplayertoucher]] (spawned by the ball) will.
|- id="npc"
| <center>COLLISION_GROUP_NPC</center>
| <center>9</center>
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Used by NPCs. Always collides with <code>COLLISION_GROUP_DOOR_BLOCKER</code>
|- id="vehicle"
| <center>COLLISION_GROUP_IN_VEHICLE</center>
| <center>10</center>
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| Set on players/NPCs which enter a vehicle.
|- id="weapon"
| <center>COLLISION_GROUP_WEAPON</center>
| <center>11</center>
| {{No}}
| {{Yes}}
| {{Yes|style=background:#FFFF00}}<br>{{tf2}} Depends
| {{Yes}}
| {{Yes}}
| Used by weapons, including when dropped.
In {{tf2}}, does not collide with rockets.
|- id="clip"
| <center>COLLISION_GROUP_VEHICLE_CLIP</center>
| <center>12</center>
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| Used by [[func_vehicleclip]]. Ony collides with <code>COLLISION_GROUP_VEHICLE</code>.
|- id="projectile"
| <center>COLLISION_GROUP_PROJECTILE</center>
| <center>13</center>
| {{Yes|style=background:#FFFF00}}<br>{{tf2}} No
| {{Yes}}
| {{No|style=background:#FFFF00}}<br>{{tf2}} Depends
| {{Yes}}
| {{Yes}}
| Set on projectiles. Does not collide with other projectiles.
In {{tf2}}, rockets and grenades have their own collision groups. This will not collide with rockets, however it does collide with grenades!
|- id="blocker"
| <center>COLLISION_GROUP_DOOR_BLOCKER</center>
| <center>14</center>
| {{No}}
| {{No}}
| {{No|style=background:#FFFF00}}<br>{{tf2}} Depends
| {{No}}
| {{No}}
| Used by [[prop_door_rotating]] (creates a [[entity_blocker]] entity). Only supposed to collide with <code>COLLISION_GROUP_NPC</code>.
In {{tf2}}, also collides with rockets, grenades and certain projectiles.
{{todo|Investigate the projectile behavior more}}
|- id="door"
| <center>COLLISION_GROUP_PASSABLE_DOOR</center>
| <center>15</center>
| {{No}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Used by [[func_door]] and [[func_door_rotating]] when the non-solid spawnflag is set.
|- id="dissolving"
| <center>COLLISION_GROUP_DISSOLVING</center>
| <center>16</center>
| {{No}}
| {{Yes}}
| {{No}}
| {{Yes}}
| {{Yes}}
| Set on entities dissolved with [[env_entity_dissolver]]. Only collides with <code>COLLISION_GROUP_NONE</code>.
|- id="pushaway"
| <center>COLLISION_GROUP_PUSHAWAY</center>
| <center>17</center>
| {{No|style=background:#FFFF00}}<br>{{hl2dm}} Yes
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Set by [[func_physbox_multiplayer]]. Also set by [[prop_physics_multiplayer]] on spawn and when awakened, if [[sv_turbophysics]] is enabled. Collides with <code>COLLISION_GROUP_DEBRIS</code>. Used to push away props from the player in {{css}} and {{dods}}.
|- id="actor"
| <center>COLLISION_GROUP_NPC_ACTOR</center>
| <center>18</center>
| {{Yes|style=background:#FFFF00}}<br>{{hl2}} No
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Set on NPCs when they are potentially stuck in a player. Behaves identically to <code>COLLISION_GROUP_NPC</code> if not testing against <code>COLLISION_GROUP_PLAYER</code>.
|- id="scripted"
| <center>COLLISION_GROUP_NPC_SCRIPTED</center>
| <center>19</center>
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Set on NPCs playing out a [[scripted_sequence]], if NPC collisions are set to be disabled.
In {{hl2}}, does not collide with other <code>COLLISION_GROUP_NPC_SCRIPTED</code>
|}

Extended collision groups in {{tf2|2}} only:

{| class="standard-table"
|- style="z-index:1; position:sticky; top:0"
! width="100px" | Name
! width="50px" | Value
! width="75px" | Solid to players
! width="75px" | Solid to hitscan
! width="75px" | Solid to projectiles
! width="75px" | Solid to physics
! width="75px" | Solid to world
! Description
|- id="grenades"
| <center>TFCOLLISION_GROUP_GRENADES</center>
| <center>20</center>
| {{No}}
| {{Yes}}
| {{N/A}}<br>Depends
| {{Yes}}
| {{Yes}}
| Set by grenade projectiles. Does not collide with other <code>TFCOLLISIONGROUP_GRENADES</code> and rockets.
|- id="object"
| <center>TFCOLLISION_GROUP_OBJECT</center>
| <center>21</center>
| {{N/A}}<br>Depends
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Set by Engineer buildings except teleporters. Uses team-specific [[$contents|contents]] on players.
|- id="solidtoplayermovement"
| <center>TFCOLLISION_GROUP_OBJECT_SOLIDTOPLAYERMOVEMENT</center>
| <center>22</center>
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Set on teleporters. 
|- id="combatobject"
| <center>TFCOLLISION_GROUP_COMBATOBJECT</center>
| <center>23</center>
| {{No}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Set by placed sappers and the medigun shield ([[entity_medigun_shield]]). 
|- id="rockets"
| <center>TFCOLLISION_GROUP_ROCKETS</center>
| <center>24</center>
| {{No}}
| {{Yes}}
| {{No}}
| {{Yes}}
| {{Yes}}
| Set by rocket projectiles. Collides with <code>COLLISION_GROUP_PLAYER</code> but not player movement. Does not collide with weapons or any projectiles except rockets. Collides with medigun shields.
|- id="respawnrooms"
| <center>TFCOLLISION_GROUP_RESPAWNROOMS</center>
| <center>25</center>
| {{Yes}}
| {{No}}
| {{No}}
| {{No}}
| {{No}}
| Used by [[func_respawnroom]] and [[func_respawnroomvisualizer]]. 
|- id="tank"
| <center>TFCOLLISION_GROUP_PUMPKIN_BOMB</center>
| <center>26</center>
| {{No}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| {{Yes}}
| Set by team-assigned [[tf_pumpkin_bomb]]s.
|- id="rockets"
| <center>TFCOLLISION_GROUP_ROCKET_BUT_NOT_WITH_OTHER_ROCKETS</center>
| <center>27</center>
| {{No}}
| {{Yes}}
| {{No}}
| {{Yes}}
| {{Yes}}
| Set by arrows and the Short Circuit's secondary attack ([[tf_projectile_mechanicalarmorb]]). Same as <code>TFCOLLISION_GROUP_ROCKETS</code> but doesn't collide with other rockets.
|}
== Table ==