momentary_rot_button
momentary_rot_button
is a brush entity available in all Source games.
It is designed to be used for rotating wheels, where the player can rotate them to arbitrary positions before stopping.

Toggle (Disable Auto Return)
flag is enabled and usage is paused, the button will start turning backwards the next time it is used. It will still fire the "OnPressed" outputs as usual, but just rotating the other way.The button will turn backwards until the starting position is reached. At which point the button will look like it stops turning, but it can still be held down until theOnReachedPosition
output will fire.

Toggle (Disable Auto Return)
flag and set the Auto-return speed
to 0.00000000000000000000000000001.
That way it does, technically, turn backwards on its own, but it seemingly stands still. Allowing the button to keep turning forwards when used again.
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CMomentaryRotButton defined in ![]() buttons.cpp
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Contents
Keyvalues
- Speed (deg/sec) <integer>
- The amount, in degrees, that the wheel turns per second.
- Master (Obsolete) <string>
- Legacy support: The name of a master entity. If the master hasn't been activated, this button cannot be used.
- Sounds <choices>
- Sound to play after being turned.
Value Description 0
None 1
Big zap & Warmup 2
Access Denied 3
Access Granted 4
Quick Combolock 5
Power Deadbolt 1 6
Power Deadbolt 2 7
Plunger 8
Small zap 9
Keycard Sound 21
Squeaky 22
Squeaky Pneumatic 23
Ratchet Groan 24
Clean Ratchet 25
Gas Clunk
- Distance <integer>
- The maximum amount, in degrees, that the wheel is allowed to rotate.
- Auto-return speed <integer>
- If the 'Toggle' spawnflag is not set, the speed at which the wheel auto-returns when left alone, in degrees per second.
- Minimum Light Level <string>
- The minimum level of ambient light that hits this brush.
- Start Position <float>
- Postion when spawned. The value is a range between 0.0 and 1.0, where 0 is the unrotated position and 1 is the rotated position + 'Distance'.
- Start Direction <choices>
- Which way the wheel turns.
- -1 : Forward
- 1 : Backward
- Solid BSP <boolean>
- Set this if this brush is in hierarchy with a moving object of some kind, and the player can stand on this brush.
Targetname:
- Name
(targetname)
<string> - The targetname that other entities refer to this entity by.
Parentname:
- Parent
(parentname)
<targetname> - Specifies a movement parent. An entity will maintain its initial offset from its parent. An attachment point can be added to the end of the name, separated by a comma.
Origin:
- Origin (X Y Z)
(origin)
<origin> - The position of this entity's center in the world. Rotating entities typically rotate around their origin.
Angles:
- Pitch Yaw Roll (Y Z X)
(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.
RenderFields:
- Render Mode
(rendermode)
<choices> - Set a non-standard rendering mode on this entity.
- 0: Normal
- 1: Color
- 2: Texture
- 3: Glow
- 4: Solid/Alphatest
- 5: Additive
- 6: Removed, does nothing
- 7: Additive Fractional Frame
- 8: Alpha Add
- 9: World Space Glow
- 10: Don't Render
- Render FX / Transparency (0 - 255)
(renderamt)
<integer> - Transparency amount, requires a Render Mode other than Normal. 0 is invisible, 255 is fully visible.
- Render Color (R G B)
(rendercolor)
<color255> - Color tint.
- Disable Receiving Shadows
(disablereceiveshadows)
<boolean> - Prevent the entity from receiving shadows on itself.
- Render FX
(renderfx)
<choices> - Various somewhat legacy alpha effects.


- 0: None
- 1: Slow Pulse (varies alpha by ±16 over a period of 1.5 s)
- 2: Fast Pulse (varies alpha by ±16 over a period of 0.4 s)
- 3: Slow Wide Pulse (varies alpha by ±64 over a period of 1.5 s)
- 4: Fast Wide Pulse (varies alpha by ±64 over a period of 0.4 s)
- 5: Slow Fade Away (decreases alpha by -1 per frame/(in all games since
) Fades out over 4 s)
- 6: Fast Fade Away (decreases alpha by -4 per frame/(in all games since
) Fades out over 1 s)
- 7: Slow Become Solid (increases alpha by +1 per frame/(in all games since
) Fades in over 4 s)
- 8: Fast Become Solid (increases alpha by +4 per frame/(in all games since
) Fades in over 1 s)
- 9: Slow Strobe (transparent 0.8 s, visible 0.8 s, repeat)
- 10: Fast Strobe (transparent 0.2 s, visible 0.2 s, repeat)
- 11: Faster Strobe (transparent 0.09 s, visible 0.09 s, repeat)
- 12: Slow Flicker (transparent 0.18 s, visible 1.5 s, repeat)
- 13: Fast Flicker (transparent 0.14 s, visible 0.2 s, repeat)
- 14: Constant Glow ("NoDissipation;" purpose uncertain—for sprites?) (not in
)
- 15: Distort (causes unnatural flickering and position shifting)/(in all games since
) Fade Out (instant; not very useful outside of code)
- 16: Hologram (Distort + "distance fade")/(in all games since
) Fade In (instant; not very useful outside of code)
- 17: Scale Up ("Explode"/"scale up really big!" causes wild stretching of model parts) (in
)/Fade Wider Pulse (varies alpha by ±255 over a period over a period of 0.26 s) (in all games since
)
Confirm:which branches/games is it available in, and where does it do what?
- 18: Glow Shell (purpose unclear) (in all games since
) (not in
)
Confirm:what does this do? and which games is it in?
- 19: Clamp Minimum Scale ("keep this sprite from getting very small (SPRITES only!)") (not in
)
- 20: Environmental Rain ("for environmental rendermode, make rain") (in
) (not in
)
Confirm:which games? may be nonfunctional.
- 21: Environmental Snow ("for environmental rendermode, make snow") (in
) (not in
)
Confirm:which games? may be nonfunctional.
- 22: Spotlight FX ("TEST CODE for experimental spotlight") (in
) (not in
)
- 23: Ragdoll ("HACKHACK: TEST CODE for signalling death of a ragdoll character;" ragdolls an entity but doesn't kill it) (in
) (not in
)
Confirm:which games? may be nonfunctional?
- 24: Fade Wider Pulse (varies alpha by ±255 over a period over a period of 0.26 s) (in
) (not in
)
- 25:
kRenderFXMax
/Fade Near (removed since) (not in
)
Todo: what does this do? may be nonfunctional
Flags
- [
1
] : Not Solid - [
32
] : Toggle (Disable Auto Return) - [
64
] : X Axis - [
128
] : Y Axis - [
1024
] : Use Activates - [
2048
] : Starts locked - [
8192
] : Jiggle when used while locked - [
16384
] : Non-Solid (only in)
Note:doesn't do anything
Inputs
Lock
- Lock the button, preventing it from functioning.
Unlock
- Unlock the button, allowing it to function.
SetPosition
<string>- Move to a position. The parameter must be a value between 0 and 1, where 0 is the unrotated position and 1 is the rotated position + 'Distance'.
SetPositionImmediately
<string>- Immediately teleport to a position. The parameter must be a value between 0 and 1, where 0 is the unrotated position and 1 is the rotated position + 'Distance'.
_DisableUpdateTarget
- Prevent the Position output from firing. Used to implement "jiggle when locked" by firing
SetPosition
inputs.
_EnableUpdateTarget
- Allow the Position output to fire again. Used to implement "jiggle when locked" by firing
SetPosition
inputs.
Base:
AddContext
<string>- Adds to the entity's list of response contexts. See Context.
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:
// 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"
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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
toFireUser4
- Fires the respective
OnUser
outputs; 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 thanKill
input.
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.
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) (also in
)
- 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) (also in
)
- 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) (also in
) !FGD
- Calls a VScript function defined in the scope of the receiving entity.
TerminateScriptScope
(only in) !FGD
- Destroys the script scope of the receving 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.
Parentname:
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.
ClearParent
- Removes this entity from the the movement hierarchy, leaving it free to move independently.
RenderFields:
Alpha
<integer 0–255>- Sets the entity's transparency to a number from 0 (invisible) to 255 (fully visible). Requires the entity to have its
rendermode
set to a number other than0
.
Color
<color255>- Sets an RGB color for the entity.
Outputs
Position
<integer>- Fired whenever the button moves. The output is the position of button from 0 to 1, where 0 is the unrotated position and 1 is the rotated position + 'Distance'.
OnPressed
<integer>- Fired when the button is first pressed.
OnUnpressed
<integer>- Fired when the button is first released from being pressed.
OnFullyClosed
- Fired when the button has reached position 1, the rotated position + 'Distance'.
OnFullyOpen
- Fired when the button has reached position 0, the unrotated starting position.
OnReachedPosition
- Fired whenever the button reaches a goal position: i.e. when it becomes open, becomes closed, or reaches the point specified by a '
SetPosition
' input.
Targetname:
OnUser1
toOnUser4
- These outputs each fire in response to the firing of the like-numbered
FireUser1
toFireUser4
Input; see User Inputs and Outputs.