Func rotating

GoldSrc

Source Engine

Class hierarchy
CFuncRotating ↳CBaseEntity
bmodels.cpp

func_rotating is a brush entity available in all Source games.

Bug:Always fire the Stop input on this entity before killing it, otherwise looping sounds may continue playing forever!  [todo tested in ?]

Bug:The maximum degrees this angle can turn is 360000 degrees, at which it stops rotating. Periodically fire the Stop/Start inputs as a workaround  [todo tested in ?]

Workaround:Both bugs mentioned above can be fixed in VScript supported titles with the following entity script.

// save this to a new file in your /scripts/vscripts/ folder and set the `vscripts` keyvalue on the entity to the filename.
function OnPostSpawn()
{
    // m_angRotation will fail to hit 360,000.0, reset it a bit earlier
    local maxangle = 359000.0
    local xyz = array(3, 0.0)

    self.ValidateScriptScope()
    local scope = self.GetScriptScope()

    // if using your own think function, copy the contents from this function to yours and delete this.
    scope.RotateFixThink <- function() {

        for (local i = 0; i < 3; i++)
        {
            xyz[i] = NetProps.GetPropFloat(self, format("m_angRotation[%d]", i))

            if ( xyz[i] == 0.0 || xyz[i] < maxangle) continue

            xyz[i] %= 360.0
            self.SetLocalAngles(QAngle(xyz[0], xyz[1], xyz[2]))
            break
        }
        return -1
    }
    // remove this if setting your own think separately.
    AddThinkToEnt(self, "RotateFixThink")

    scope.noise <- NetProps.GetPropString(self, "m_NoiseRunning")

    // see OnDestroy callback on the script functions page.
    scope.setdelegate({}.setdelegate({
        id       = self.GetScriptId()
        index    = self.entindex()
        parent   = scope.getdelegate()
        _delslot = function(k)
        {
            if (k == id)
            {
                local ent = EntIndexToHScript(index)
                StopAmbientSoundOn(ent.GetScriptScope().noise, ent)
            }
            delete parent[k];
        }
    }))
}

Entity Description

A visual guide showing the axis in each viewport (Click to enlarge)

It is used to create rotating brushes. Compare with func_door_rotating.

Friction Explanation & Formula

Fan friction may be a little tricky to understand. Below is an explanation of how it works.

If Hammer has the fanfriction key set to 0 and the game spawns the entity, code sets it to 1 so it doesn't divide by zero.

Friction = fanfriction key / 100

---

Key	Hammer Value	Code Value
fanfriction	100	1
fanfriction	50	0.5
fanfriction	0/1	0.01

---

Note: These formulas get called every 0.1 seconds.

Purpose: Think function: Accelerates a func_rotating to a higher angular velocity.

new_speed = fabs( current_speed ) + 0.2 * maxspeed * fanfriction;

Purpose: Decelerates the rotator from a higher speed to a lower one.

new_speed = fabs( current_speed ) - 0.1 * maxspeed * fanfriction;

---

Conclusion:

• A higher fanfriction value will accelerate/deaccelerate faster.
• A lower fanfriction value will accelerate/deaccelerate slower.

Keyvalues

Note:For Keyvalues and Inputs affecting brush rendering, see Brush entity/Rendering related keyvalues and inputs

Name (targetname) <string>[ Edit ]

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

Max Rotation Speed (maxspeed) <float>

The maximum rotation speed of the brushes, in degrees per second. Seems to be limited to a number around 2000, after which the rotational speed ignores the last remaining digits (e.g., 2500=250).

Friction (0 - 100%) (fanfriction) <float>

The amount of rotational friction. Value must be between 0 and 100 %. The lower the friction is, the slower it spins up and spins down. This is the opposite of how it would work in real life.

Note:Defaults to 100% if set to zero.

Rotating sound WAV (message) <sound>

Sound to play while rotating.

Bug:Always fire the Stop input on this entity before killing it, otherwise looping sounds may continue playing forever!  [todo tested in ?]

Volume (10 = loudest) (volume) <integer>

The volume of the rotation sound.

Blocking Damage (dmg) <integer>

Damage done to any entity that blocks the rotation, per frame.

Solid Type (solidbsp) <boolean>

Brush solidity type

• 0 : VPhysics
• 1 : BSP

Flags

Start ON : [1]

Reverse Direction : [2]

X Axis : [4]

If enabled, the entity will spin at the X Axis.

Y Axis : [8]

If enabled, the entity spin at the Y Axis.

Acc/Dcc : [16]

If enabled, the entity will accelerate and decelerate from maximum speed based on the Friction property.

Client-side Rotation : [16] (only in )

Intended to simulate the entity entirely on the client.

Note: This entity did not rotate visually until the 19/12/2018 patch, due to bugged implementation of the Client-side rotation spawnflag.

Fan Pain : [32]

With this enabled, the player will be hurt when coming into contact with the brush.

Not Solid : [64]

Small Sound Radius : [128]

Use ATTN_IDLE (60dB).

Medium Sound Radius : [256]

Use ATTN_STATIC (~67dB).

Large Sound Radius : [512]

Use ATTN_NORM (~75dB). If the other two options are unset, this is used.

Client-side Animation : [1024] (in all games since )

Inputs

SetSpeed <floatRedirectInput/float>

Set the speed as a ratio of the specified Max Rotation Speed, where 0 is stopped and 1 is the Max Rotation Speed. Negative values rotate backwards.
If you want to set by degrees per second instead, first fire "Addoutput - Maxspeed X" to this entity, followed by "Start" with a delay of 0.01 seconds.

Start

Start the rotator rotating.

Stop

Stop the rotator from rotating.

StopAtStartPos

Stop the rotator from rotating when it gets around to the start position again (on its rotation axis). If the speed is greater than 100 degrees per second, slows down to 100 degrees per second and spins for one extra revolution before stopping.

StartForward

Start the rotator rotating forward at maximum speed.

StartBackward

Start the rotator rotating backward at maximum speed.

Toggle

Toggle the rotator between rotating and not rotating.

Reverse

Reverse the direction of rotation of the rotator, preserving the current speed.

SnapToStartPos  (in all games since )

Snap to the initial position and stop moving.

GetSpeed  (in all games since )

Causes the func_rotating to fire its OnGetSpeed output with its current speed.

Outputs

OnGetSpeed <integerRedirectOutput/integer> (in all games since )

Fired when the GetSpeed input is called. The current speed of the func_rotating is passed with this output.

See also

• func_door_rotating
• func_platrot
• func_rot_button
• momentary_rot_button