func_occluder

Green boxes represent occluded props, red boxes unoccluded ones.

func_occluder is a brush entity available in all Source games.

Entity Description

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 in-game 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.

Occluders are very useful in cases where you have reasonably large func_detail, prop, or func_brush walls. These walls do not cut visleaves and therefore will not stop props from rendering behind these walls. Adding an occluder inside the same wall will at the very least hide all props behind the brush entity walls.

Usually, all faces of a func_occluder are Nodraw or Skip (as seen in Counter-Strike: Global Offensive maps), with the occluding faces using the Occluder or Trigger texture.
The occlusion will only work if the player is looking at the side that has the occluding texture "visible." If the back side is Nodraw, the occlusion will not take place if looked at from the other side.

Usage

Texture on a func_occluder	Effect of that face
	Occlude
	Don't Occlude

Texturing

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.

Debugging Commands

r_occlusion

Activate/deactivate the occlusion system.

r_visocclusion

Activate/deactivate wireframe rendering of what the occlusion system is doing.

r_drawpixelvisibility

Show the occlusion proxies

r_occludeemaxarea

Prevents occlusion testing for entities that take up more than X% of the screen. 0 means use whatever the level said to use.

r_occluderminarea

Prevents occlusion testing for entities that take up less than X% of the screen. 0 means use whatever the level said to use.

r_occlusionspew

Activate/deactivates spew about what the occlusion system is doing.

r_occludermincount

At least this many occluders will be used, no matter how big they are.

Keyvalues

Initial State (StartActive) <choices>

If the entity starts inactive, use the Activate or Toggle inputs to turn it on. Default value is 1.

• 0: Inactive
• 1: Active

Base:

Collisions (solid) <choices>

Method of collision for this entity.

 

• 0: None
• 1: BSP (QPhysics) !FGD
   Bug: In , if an entity using QPhysics collisions is hit by Gel, the game will crash!
• 2: Bounding Box
• 3: Oriented Bounding Box (Use for runtime spawned brush entities meant to be rotated) !FGD
• 4: Oriented Bounding Box but constrained to Yaw only !FGD
• 5: Custom/Test (Usually no collision with anything) !FGD
• 6: VPhysics

Name (targetname) <string>

The name that other entities use to refer to this entity.

Parent (parentname) <targetname>

Maintain the same initial offset to this entity. An attachment point can also be used if separated by a comma at the end. (parentname [targetname],[attachment])

 Tip: Entities transition to the next map with their parents

 Tip: phys_constraintcan be used as a workaround if parenting fails.

Origin (X Y Z) (origin) <coordinates>

The position of this entity's center in the world. Rotating entities typically rotate around their origin.

 Note: Hammer does not move the entities accordingly only in the editor.

Pitch Yaw Roll (X Y Z) (angles) <angle>

This entity's orientation in the world. Pitch is rotation around the Y axis, yaw is the rotation around the Z axis, roll is the rotation around the X axis.

 Note: This works on brush entities, although Hammer doesn't show the new angles.

Classname (classname) <string> !FGD

Determines the characteristics of the entity before it spawns.

 Tip: Changing this on runtime still has use, like making matching an entry in S_PreserveEnts will persist the entity on new rounds!

Flags (spawnflags) <integer> !FGD

Toggles exclusive features of an entity, its specific number is determined by the combination of flags added.

Effects (effects) <integer> !FGD

Combination of effect flags to use.

Entity Scripts (vscripts) <scriptlist> (in all games since )

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.

Think function (thinkfunction) <string> (in all games since )

Name of the function within this entity's script that'll be called automatically every 100 milliseconds, or a user-defined interval if the function returns a number. Avoid expensive operations in this function, as it may cause performance problems.

Lag Compensation (LagCompensate) <boolean> (in all games since ) !FGD

Set to Yes to lag compensate this entity. Should be used very sparingly!

Is Automatic-Aim Target (is_autoaim_target) <boolean> (in all games since ) !FGD

If set to 1, this entity will slow down aiming movement for consoles and joystick controllers when the entity is under the crosshairs.

Inputs

Activate

Deactivate

Toggle

Control the state of the occluder.

Base:

AddContext <string>

Adds to the entity's list of response contexts. Format is <key>:<value>.

AddOutput <string>

Assigns a new keyvalue/output on this entity. For keyvalues, some rely on extra necessary code to be ran and won't work if its simply just changed through this input. There is a strict format that must be followed:

Syntax: 

// Format of changing KeyValues: "AddOutput [key] [value]"
//// Raw text:
"OnUser1" "!self,AddOutput,targetname new_name"

// Format of adding an Output: "AddOutput {targetname}:{inputname}:{parameter}:{delay}:{max times to fire, -1 means infinite}"
//// Raw text:
"OnUser1" "!self,AddOutput,OnUser1:SetParent:!activator:0.0:-1"
// Arguments can be left blank, but the empty blank should still be contained.
//// Raw text:
"OnUser1" "!self,AddOutput,OnUser1:ClearParent::0.0:-1"

ClearContext

Removes all contexts from this entity's list.

ClearParent

Removes this entity from the the movement hierarchy, leaving it free to move independently.

FireUser1 to FireUser4

Fires the respectiveOnUseroutputs; see User Inputs and Outputs.

Kill

Removes this entity and any entities parented to it from the world.

KillHierarchy

Functions the same as Kill, although this entity and any entities parented to it are killed on the same frame, being marginally faster thanKillinput.

RemoveContext <string>

Remove a context from this entity's list. The name should match the key of an existing context.

SetParent <string>

Move with this entity. See Entity Hierarchy (parenting).

SetParentAttachment <string>

Change this entity to attach to a specific attachment point on its parent. The entity will teleport so that the position of its root bone matches that of the attachment. Entities must be parented before being sent this input.

SetParentAttachmentMaintainOffset <string>

As above, but without teleporting. The entity retains its position relative to the attachment at the time of the input being received.

Use  !FGD

Same as a player invoking +use; no effect in most cases.

DispatchResponse <string> !FGD

Dispatches a response to the entity. See Response and Concept.

DispatchEffect <string> (removed since ) !FGD

Dispatches a special effect from the entity's origin; see also List of Client Effects. Replaced by the particle system since .

RunScriptFile <script> (in all games since )

Execute a VScript file from disk, without file extension. The script contents are merged with the script scope of the receiving entity.

RunScriptCode <string> (in all games since )

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: In Hammer, using string arguments will corrupt the VMF file's structure, making the file unviewable for the next Hammer session.

Fix: Remove the string argument manually with a text editor.

CallScriptFunction <string> (in all games since ) !FGD

Calls a VScript function defined in the scope of the receiving entity.

SetLocalOrigin <coordinates> (in all games since ) !FGD

Send this entity to a spot in the map. If the entity is parented to something, it will be offset from the parent by this amount.

SetLocalAngles <angles> (in all games since ) !FGD

Set this entity's angles.

Outputs

Base:

OnUser1 to OnUser4

These outputs each fire in response to the firing of the like-numbered FireUser1 to FireUser4 Input; see User Inputs and Outputs.

OnKilled  (only in )

This output fires when the entity is killed and removed from the game.

External Links

• Visibility Optimization
• Wikipedia on Antiportals