S PreserveEnts

In multiplayer Source games, all entities are set back to their defaults during a round reset by removing and immediately respawning them, unless their current classnames match an entry in the s_PreserveEnts whitelist. Whitelisted entities either have special code to handle the reset process or none at all, and the entity is therefore considered not ideal for removal.

Some whitelisted entities may not properly account for round resets and are likely to carry their previous properties over to the next round, such as their origins.

Note:

• Some games might not have any way to reset the round (even through mp_forcewin or mp_restartgame commands).
• Contexts aren't preserved between round restart even for preserved entities  (tested in: Left 4 Dead 2)

Games	Has Whitelist	Has Rounds	Notes
Counter-Strike: Source	Yes	Yes
Half-Life: Source	No	-
Half-Life Deathmatch: Source	No	-
Half-Life 2	No	-
Half-Life 2: Deathmatch	Yes	No	Round can be reset using mp_restartgame
Day of Defeat: Source	Yes	Yes
Half-Life 2: Episode One	No	-
Half-Life 2: Episode Two	No	-
Portal	No	-	Whitelist exists, but is not included in the compiled DLLs.
Team Fortress 2	Yes	Yes
Left 4 Dead	Yes	Yes
Left 4 Dead 2	Yes	Yes
Alien Swarm Alien Swarm: Reactive Drop	Yes	No	asw_instant_restart 1 should allow for round reset without full map reload but seems to always crash the game instead in . It's the default behavior in and works properly. Uses m_MapResetFilter.AddKeepEntity() function instead of s_PreserveEnts[] array.
Portal 2	Yes	No	Can round be reset in coop?[confirm]
Counter-Strike: Global Offensive	Yes	Yes

Behavior

If the game has round restart mechanics, a preserved entity may not behave as expected:

• On a new round entities with this classname will intentionally not reset. You can use logic_auto to emulate resetting it.
• Killing it removes it forever, as it is not respawned on a new round.
• It cannot be spawned with a point_template.
• Parenting this with non-preserved entities may have undesirable effects.

Lists

Note:Some entities don't exist in the given games despite being in s_preservedEnts list. (for example info_node* entities in )

Source Code

Alien Swarm

swarm/asw_gamerules.cpp

CAlienSwarm::CAlienSwarm() { // set which entities should stay around when we restart the mission m_MapResetFilter.AddKeepEntity("worldspawn"); m_MapResetFilter.AddKeepEntity("soundent"); m_MapResetFilter.AddKeepEntity("asw_gamerules"); m_MapResetFilter.AddKeepEntity("player"); m_MapResetFilter.AddKeepEntity("asw_player"); m_MapResetFilter.AddKeepEntity("player_manager"); m_MapResetFilter.AddKeepEntity("predicted_viewmodel"); m_MapResetFilter.AddKeepEntity("sdk_team_manager"); m_MapResetFilter.AddKeepEntity("scene_manager"); m_MapResetFilter.AddKeepEntity("event_queue_saveload_proxy"); m_MapResetFilter.AddKeepEntity("ai_network"); }

Alien Swarm: Reactive Drop

swarm/asw_gamerules.cpp

// set which entities should stay around when we restart the mission m_MapResetFilter.AddKeepEntity( "worldspawn" ); m_MapResetFilter.AddKeepEntity( "soundent" ); m_MapResetFilter.AddKeepEntity( "asw_gamerules" ); m_MapResetFilter.AddKeepEntity( "player" ); m_MapResetFilter.AddKeepEntity( "asw_player" ); m_MapResetFilter.AddKeepEntity( "player_manager" ); m_MapResetFilter.AddKeepEntity( "predicted_viewmodel" ); m_MapResetFilter.AddKeepEntity( "sdk_team_manager" ); m_MapResetFilter.AddKeepEntity( "scene_manager" ); m_MapResetFilter.AddKeepEntity( "event_queue_saveload_proxy" ); m_MapResetFilter.AddKeepEntity( "ai_network" ); m_MapResetFilter.AddKeepEntity( "ai_hint" ); m_MapResetFilter.AddKeepEntity( "info_node" ); m_MapResetFilter.AddKeepEntity( "info_hint" ); m_MapResetFilter.AddKeepEntity( "info_node_hint" ); m_MapResetFilter.AddKeepEntity( "info_node_air" ); m_MapResetFilter.AddKeepEntity( "info_node_air_hint" ); m_MapResetFilter.AddKeepEntity( "info_node_climb" ); m_MapResetFilter.AddKeepEntity( "info_marine_hint" ); m_MapResetFilter.AddKeepEntity( "info_node_marine_hint" ); m_MapResetFilter.AddKeepEntity( "infodecal" ); // riflemod: keep health regen entity all the time m_MapResetFilter.AddKeepEntity( "asw_health_regen" );

Counter-Strike: Global Offensive

cstrike15/cs_gamerules.cpp

static const char *s_PreserveEnts[] = { "ai_network", "ai_hint", "cs_gamerules", "cs_team_manager", "cs_player_manager", "env_soundscape", "env_soundscape_proxy", "env_soundscape_triggerable", "env_sun", "env_wind", "env_fog_controller", "env_tonemap_controller", "env_cascade_light", "func_brush", "func_wall", "func_buyzone", "func_illusionary", "func_hostage_rescue", "func_bomb_target", "infodecal", "info_projecteddecal", "info_node", "info_target", "info_node_hint", "info_player_counterterrorist", "info_player_terrorist", "info_enemy_terrorist_spawn", "info_deathmatch_spawn", "info_armsrace_counterterrorist", "info_armsrace_terrorist", "info_map_parameters", "keyframe_rope", "move_rope", "info_ladder", "player", "point_viewcontrol", "point_viewcontrol_multiplayer", "scene_manager", "shadow_control", "sky_camera", "soundent", "trigger_soundscape", "viewmodel", "predicted_viewmodel", "worldspawn", "point_devshot_camera", "logic_choreographed_scene", "cfe_player_decal", "info_bomb_target_hint_A", "info_bomb_target_hint_B", "info_hostage_rescue_zone_hint", "generic_actor", "vote_controller", "wearable_item", "point_hiding_spot", "game_coopmission_manager", "chicken", "", // END Marker };

Counter-Strike: Source

cstrike/cs_gamerules.cpp

static const char *s_PreserveEnts[] = { "ai_network", "ai_hint", "cs_gamerules", "cs_team_manager", "cs_player_manager", "env_soundscape", "env_soundscape_proxy", "env_soundscape_triggerable", "env_sun", "env_wind", "env_fog_controller", "func_brush", "func_wall", "func_buyzone", "func_illusionary", "func_hostage_rescue", "func_bomb_target", "infodecal", "info_projecteddecal", "info_node", "info_target", "info_node_hint", "info_player_counterterrorist", "info_player_terrorist", "info_map_parameters", "keyframe_rope", "move_rope", "info_ladder", "player", "point_viewcontrol", "scene_manager", "shadow_control", "sky_camera", "soundent", "trigger_soundscape", "viewmodel", "predicted_viewmodel", "worldspawn", "point_devshot_camera", "", // END Marker };

Day of Defeat: Source

dod/dod_gamerules.cpp

static const char *s_PreserveEnts[] = { "player", "viewmodel", "worldspawn", "soundent", "ai_network", "ai_hint", "dod_gamerules", "dod_team_manager", "dod_player_manager", "dod_objective_resource", "env_soundscape", "env_soundscape_proxy", "env_soundscape_triggerable", "env_sprite", "env_sun", "env_wind", "env_fog_controller", "func_brush", "func_wall", "func_illusionary", "info_node", "info_target", "info_node_hint", "info_player_allies", "info_player_axis", "point_viewcontrol", "shadow_control", "sky_camera", "scene_manager", "trigger_soundscape", "info_dod_detect", "dod_team_allies", "dod_team_axis", "point_commentary_node", "dod_round_timer", "func_precipitation", "func_team_wall", "", // END Marker };

Half-Life 2: Deathmatch

hl2mp/hl2mp_gamerules.cpp

static const char *s_PreserveEnts[] = { "ai_network", "ai_hint", "hl2mp_gamerules", "team_manager", "player_manager", "env_soundscape", "env_soundscape_proxy", "env_soundscape_triggerable", "env_sun", "env_wind", "env_fog_controller", "func_brush", "func_wall", "func_buyzone", "func_illusionary", "infodecal", "info_projecteddecal", "info_node", "info_target", "info_node_hint", "info_player_deathmatch", "info_player_combine", "info_player_rebel", "info_map_parameters", "keyframe_rope", "move_rope", "info_ladder", "player", "point_viewcontrol", "scene_manager", "shadow_control", "sky_camera", "soundent", "trigger_soundscape", "viewmodel", "predicted_viewmodel", "worldspawn", "point_devshot_camera", "", // END Marker };

Portal 2

portal/portal_mp_gamerules.cpp

static const char *s_PreserveEnts[] = { "ai_network", "ai_hint", "hl2mp_gamerules", "team_manager", "player_manager", "env_soundscape", "env_soundscape_proxy", "env_soundscape_triggerable", "env_sun", "env_wind", "env_fog_controller", "func_brush", "func_wall", "func_buyzone", "func_illusionary", "infodecal", "info_projecteddecal", "info_node", "info_target", "info_node_hint", "info_player_deathmatch", "info_player_combine", "info_player_rebel", "info_map_parameters", "keyframe_rope", "move_rope", "info_ladder", "player", "point_viewcontrol", "scene_manager", "shadow_control", "sky_camera", "soundent", "trigger_soundscape", "viewmodel", "predicted_viewmodel", "worldspawn", "point_devshot_camera", "", // END Marker };

Team Fortress 2

teamplayroundbased_gamerules.cpp

// Classnames of entities that are preserved across round restarts static const char *s_PreserveEnts[] = { "player", "viewmodel", "worldspawn", "soundent", "ai_network", "ai_hint", "env_soundscape", "env_soundscape_proxy", "env_soundscape_triggerable", "env_sprite", "env_sun", "env_wind", "env_fog_controller", "func_wall", "func_illusionary", "info_node", "info_target", "info_node_hint", "point_commentary_node", "point_viewcontrol", "func_precipitation", "func_team_wall", "shadow_control", "sky_camera", "scene_manager", "trigger_soundscape", "commentary_auto", "point_commentary_node", "point_commentary_viewpoint", "bot_roster", "info_populator", "", // END Marker };

tf/tf_gamerules.cpp

// Classnames of entities that are preserved across round restarts static const char *s_PreserveEnts[] = { "tf_gamerules", "tf_team_manager", "tf_player_manager", "tf_team", "tf_objective_resource", "keyframe_rope", "move_rope", "tf_viewmodel", "tf_logic_training", "tf_logic_training_mode", "tf_powerup_bottle", "tf_mann_vs_machine_stats", "tf_wearable", "tf_wearable_demoshield", "tf_wearable_robot_arm", "tf_wearable_vm", "tf_logic_bonusround", "vote_controller", "monster_resource", "tf_logic_medieval", "tf_logic_cp_timer", "tf_logic_tower_defense", // legacy "tf_logic_mann_vs_machine", "func_upgradestation", "entity_rocket", "entity_carrier", "entity_sign", "entity_saucer", "tf_halloween_gift_pickup", "tf_logic_competitive", "tf_wearable_razorback", "entity_soldier_statue", "", // END Marker };

Code Dumps

To find the S_PreserveEnts whitelist in the Left 4 Dead games in IDA:

1. Search for the ai_network string reference.
2. Bring up all applicable XREFs.
3. Search for the list that includes survivor_bot and logic_versus_random.

Left 4 Dead

; "ai_network", ; "ai_hint", ; "cs_team_manager", ; "terror_gamerules", ; "terror_player_manager", ; "survivor_bot", ; "env_tonemap_controller", ; "env_tonemap_controller_infected", ; "env_tonemap_controller_ghost", ; "vote_controller", ; "env_soundscape", ; "env_soundscape_proxy", ; "env_soundscape_triggerable", ; "env_sun", ; "env_wind", ; "env_fog_controller", ; "func_wall", ; "func_buyzone", ; "func_illusionary", ; "func_hostage_rescue", ; "func_bomb_target", ; "infodecal", ; "info_projecteddecal", ; "info_node", ; "info_target", ; "info_node_hint", ; "info_player_counterterrorist", ; "info_player_terrorist", ; "info_map_parameters", ; "info_map_parameters_versus", ; "info_ladder", ; "func_simpleladder", ; "player", ; "point_viewcontrol", ; "scene_manager", ; "shadow_control", ; "sky_camera", ; "soundent", ; "trigger_soundscape", ; "viewmodel", ; "predicted_viewmodel", ; "worldspawn", ; "point_devshot_camera", ; "info_survivor_position", ; "logic_versus_random",

Left 4 Dead 2

; "ai_network", ; "ai_hint", ; "cs_team_manager", ; "terror_gamerules", ; "terror_player_manager", ; "survivor_bot", ; "env_tonemap_controller", ; "env_tonemap_controller_infected", ; "env_tonemap_controller_ghost", ; "vote_controller", ; "env_soundscape", ; "env_soundscape_proxy", ; "env_soundscape_triggerable", ; "env_sun", ; "env_wind", ; "env_fog_controller", ; "func_wall", ; "infodecal", ; "info_projecteddecal", ; "info_node", ; "info_node_hint", ; "info_map_parameters", ; "info_map_parameters_versus", ; "info_ladder", ; "func_simpleladder", ; "player", ; "point_viewcontrol", ; "scene_manager", ; "shadow_control", ; "sky_camera", ; "soundent", ; "trigger_soundscape", ; "viewmodel", ; "predicted_viewmodel", ; "worldspawn", ; "point_devshot_camera", ; "weapon_scavenge_item_spawn", ; "logic_versus_random",