func_occluder is a brush entity available in all Source games.
It hides models that are entirely covered by it in the player's view, according to how it has been textured. They are used to control visibility in places where func_areaportals or world brushes are unsuitable. Calculations of model visibility ingame is done in real time and is not in the final compile process. Use func_occluders wisely because they do calculations in real time and can cost a lot of CPU if there are too many in a map.
This entity works according to how materials has been applied to it:
- All sides covered with the occluder or trigger materials will occlude.
- All sides covered with the nodraw material will not occlude.
Occluders and Areaportals
There are several important differences between occluders and areaportals:
- An occluder only hides props, not world geometery or static brushes.
- An occluder does not split visleaves.
- An occluder can be free standing and does not need to separate two areas.
- Activate/deactivate the occlusion system.
- Activate/deactivate wireframe rendering of what the occlusion system is doing.
- Show the occlusion proxies
- Prevents occlusion testing for entities that take up more than X% of the screen. 0 means use whatever the level said to use.
- Prevents this occluder from being used if it takes up less than X% of the screen. 0 means use whatever the level said to use.
- Activate/deactivates spew about what the occlusion system is doing.
- At least this many occluders will be used, no matter how big they are.
- Start Active
- If the entity starts inactive, use the
Toggleinputs to turn it on.
- The targetname that other entities refer to this entity by.
- Entity Scripts
<scriptlist>(New with Left 4 Dead 2)
- Space delimited list of VScript files (without file extension) that are executed after all entities have spawned. The scripts are all executed in the same script scope, later ones overwriting any identical variables and functions.
- Script think function
<string>(New with Left 4 Dead 2)
- Name of a function in this entity's script which will be called automatically every 100 milliseconds (ten times a second) for the duration of the script. It can be used to create timers or to simulate autonomous behavior. The return value (if present) will set the time until the next call. Note:Try to avoid expensive operations in this function, as it may cause performance problems.
- Control the state of the occluder.
- Removes this entity and any entities parented to it from the world.
- Functions the same as
Kill, although entities with a large number of children are killed marginally faster.
- Evaluates a keyvalue/output on this entity. It can be potentially very dangerous, use with care.
<output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>
- Fire the
OnUseroutputs; see User Inputs and Outputs.
- Same as a player invoking +use; may not do anything. Can also be invoked by creating an output that does not specify an input.
This input is not included in Valve's FGDs.
<script>(New with Left 4 Dead 2)
- Execute a VScript file from disk, without file extension. The script contents are merged with the script scope of the receiving entity.
<string>(New with Left 4 Dead 2)
- Execute a string of VScript source code in the scope of the entity receiving the input. String quotation may be needed when fired via console. Bug:Warning:Never try to pass string parameters to a script function with this input. It will corrupt the VMF structure because of the nested quotation marks, which then must be removed manually with a text editor.
<string>(New with Left 4 Dead 2) !FGD
- Execute a VScript function in the scope of the receiving entity. Note:This input is missing from some games FGD files.
<origin>(New with Alien Swarm) !FGD
- Set this entity's origin in the map. Note:This input is missing from some games FGD files.
<angles>(New with Alien Swarm) !FGD
- Set this entity's angles in the map. Note:This input is missing from some games FGD files.
- These Outputs each fire in response to the firing of the like-numbered
FireUser4Input; see User Inputs and Outputs.
OnKilled(New with Left 4 Dead)
- This Output fires when the entity is killed and removed from the game.