A "simple" system to make a functional "Leash" in VRchat using OSC.
I swear I'm not a disappointment to my parents. This is kinda user friendly now.
This can be adapted to any pullable physbone; EG: A tail.

Step 1: Gather Leash Physbone Values

This one is simple. We receive the Leash_Stretch and Leash_Grabbed parameters.
If Leash_Grabbed becomes true, we begin reading Leash_Stretch

We'll use these values in this example:

Leash_IsGrabbed = True
Leash_Stretch = $0.95$

Step 2: Gather Directional Contact values

Based on where the constraint is aimed, it will give us 4 values.

If it was pointing South-South-West, we would get:

Leash_Z+ = $0.0$
Leash_Z- = $0.75$
Leash_X+ = $0.0$
Leash_X- = $0.25$

Step 3: MAAAATH!

Math is fun. Add the negative and positive contacts & multiply by the stretch value.

(Z_Positive - Z_Negative) * Leash_Stretch = Vertical
(X_Positive - X_Negative) * Leash_Stretch = Horizontal

So our calculation for speed output would look like:

$(0.0 - 0.75) * 0.95 = -0.7125$ = Veritcal
$(0.0 - 0.25) * 0.95 = -0.2375$ = Horizontal

Step 4: Outputs

If either value is above the walking deadzone (default 0.15) we start outputting them instead of 0.
If either value is above the running deadzone (0.7) we tell the player to run (x2 speed)

All movement values are relative to the VRC world's movement speed limits.
So we'd be moving at $142.5$% speed south and $47.5$% speed to the West.

If the values are below the deadzones or _IsGrabbed is false, send 0s for the OSC values once to stop movement.

For setup questions/support feel free to shoot me a DM or ask in #OSC-Talkin in my Discord

As with RavenBuilds's take on the OSCLeash, using OSC as an input for movement causes your arms to be locked into desktop pose, please slap some support onto this canny!

TEMPORARY WORKAROUND: Set "XboxJoystickMovement" to true in the config file. Instead of outputting movement with OSC, this will emulate an Xbox controller joystick! Skipping over the above issue entirely. This will probably be removed when VRC fixes the issue. Check the extra steps in setup for this.

1. Via an executable
   • Download latest zip from releases
   • Extract wherever.
   • Run Executable
2. From the source
   • Clone the github
   • Run pip install -r requirements.txt in the directory to install libraries
   • Run the python script

Requires VRC3 Avatar SDK.

1. Download the program via one of the above methods.
2. Define config.json settings if needed.
3. Grab the prefab from releases
4. Set the source of Leash Physbone to whatever you like, and adjust it if needed.
5. The position constrain source on Aim Target should be assigned to the last bone of your leash.
6. If your phybone is off center, copy the constraint from above and paste it on the root of the prefab.
   • The source should be the origin of your leash.
7. Make sure to reset OSC in the radial menu if this is being retrofit as an update to an avatar.
8. Run program.

There will be a setup video later.

If you are using Xbox input

• You need ViGEm installed.
• The VRC window must be focused for inputs to be recieved.

ᴹᵃⁿ ᵗʰᵉʳᵉ'ˢ ᵃ ˡᵒᵗ ᵒᶠ ˢᵉᵗᵗᶦⁿᵍˢ

The list of the parameters your leashes are using.
If you had three leashes, your list might look like this:

        "PhysboneParameters":
        [
            "Leash",
            "Leash2",
            "Leash3"
        ],

The script will automatically read from the _IsGrabbed and _Stretch parameters correlating with the above.

I wouldn't reccomend attempting this at the moment unless you understand constraints and animations.

• Depending on which is grabbed, you'll need to animate two position constraints.
  • We only care about which one was grabbed first.
• The Source of Aim Target should alernate the ends of the leashes
• The source of a psotion constraint on the OSCLeash Prefab should move between the origins of the leashes.

This will be included in a setup video eventually.

WOAAAH! Motion sickness warning! This gets a bit funky but you really don't need to worry about the math.
If you want to enable the feature make sure to set TurningEnabled to True.
This does not work well with the controller workaround
Currently Supports North, East, South, & West

If you had a leash up front and you want to turn to match the direction it's pulled from (EG: a Collar with the leash on the front) Set set the parameter on your Leash Physbone and config to Leash_North.

        "PhysboneParameters":
        [
            "Leash_North",
            "Leash_South",
            "Leash_East",
            "Leash_West"
        ],

We'll parse the name of your leath for North, South, ect based on underscores. So "Tail_South" would work.

Whenever this leash is grabbed and pulled past the deadzone it will begin to turn.
It will continue to turn until it is greater than the TurningDeadzone value.

Here's the simplified logic of the system.

if LeashDirection == "North" and Z_Positive < TurningGoal:
    TurningSpeed = ((X_Negative - X_Positive) * LeashStretch * TurningMultiplier)

If you wish to change the contacts to used for direction calculations, you can do so here.

        "DirectionalParameters":
        {
                "Z_Positive_Param": "Leash_Z+",
                "Z_Negative_Param": "Leash_Z-",
                "X_Positive_Param": "Leash_X+",
                "X_Negative_Param": "Leash_X-"
        }

{
        "IP": "127.0.0.1",
        "ListeningPort": 9001,
        "SendingPort": 9000,
        "RunDeadzone": 0.70,
        "WalkDeadzone": 0.15,
        "StrengthMultiplier": 1.2,
        "TurningEnabled": false,
        "TurningMultiplier": 0.75,
        "TurningDeadzone": 0.15,
        "TurningGoal": 90,
        "ActiveDelay": 0.1,
        "InactiveDelay": 0.5,
        "Logging": false,
        "XboxJoystickMovement": false,
        
        "PhysboneParameters":
        [
                "Leash"
        ],
        "DirectionalParameters":
        {
                "Z_Positive_Param": "Leash_Z+",
                "Z_Negative_Param": "Leash_Z-",
                "X_Positive_Param": "Leash_X+",
                "X_Negative_Param": "Leash_X-"
        }
}

• @ALeonic is responsible for a majority of v2
• @FrostbyteVR babied me through 90% of the process of making v1
• @I5UCC I stared at the code of their ThumbParamsOSC tool for a long time.
• Someone else did this but it was a closed source executable.