VRChat & Unity Export Guide

Complete guide for exporting HoloScript to VRChat worlds and Unity projects.

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Overview

HoloScript provides two paths to Unity:

Package	Target	Output	Status
@holoscript/vrchat-export	VRChat	UdonSharp scripts + prefabs	✅ Alpha
@holoscript/unity-adapter	Unity (general)	C# MonoBehaviours + prefabs	✅ Ready

                    ┌─────────────────────────┐
                    │   .hsplus (HoloScript)  │
                    └───────────┬─────────────┘
                                │
              ┌─────────────────┼─────────────────┐
              ▼                 ▼                 ▼
    ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
    │ three-adapter   │ │ unity-adapter   │ │ vrchat-export   │
    │ (Web/WebXR)     │ │ (Unity C#)      │ │ (VRChat/Udon)   │
    └─────────────────┘ └─────────────────┘ └─────────────────┘
              │                 │                 │
              ▼                 ▼                 ▼
    ┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
    │ Browser / Quest │ │ Unity Project   │ │ VRChat World    │
    │ via WebXR       │ │ Any platform    │ │ PC / Quest      │
    └─────────────────┘ └─────────────────┘ └─────────────────┘

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VRChat Export (Udon)

Prerequisites

1. Unity 2022.3.22f1 (VRChat current version)
2. VRChat Creator Companion installed
3. VRChat SDK (World SDK 3.5+)
4. UdonSharp package

Quick Start

# Install
npm install @holoscript/vrchat-export

# Export via CLI
holoscript export --target vrchat --output ./my-vrchat-world

Programmatic Export

import { HoloScriptPlusParser } from '@holoscript/core';
import { exportToVRChat } from '@holoscript/vrchat-export';

const parser = new HoloScriptPlusParser();
const { ast } = parser.parse(`
  composition "MyVRChatWorld" {
    environment {
      name: "My VRChat World"
      spawn_point: [0, 0, 0]
      max_players: 32
    }

    template "Ball" {
      @grabbable
      @throwable
      geometry: "sphere"
      color: "#ff0000"
    }

    template "Platform" {
      @climbable
      geometry: "box"
    }

    object "Ball" using "Ball" {
      position: [0, 1, 0]
    }

    object "Platform" using "Platform" {
      position: [0, -0.5, 0]
      scale: [10, 1, 10]
    }
  }
`);

const result = await exportToVRChat(ast, {
  outputDir: './VRChatWorld/Assets/HoloScript',
  projectName: 'MyWorld',
});

console.log(`Generated ${result.stats.prefabCount} prefabs`);
console.log(`Generated ${result.stats.scriptCount} UdonSharp scripts`);

HoloScript to Udon Trait Mapping

HoloScript Trait	VRChat/Udon Equivalent
@grabbable	VRC_Pickup
@throwable	VRC_Pickup + ThrowVelocity
@portal	VRCPortalMarker
@synced	UdonSynced variable
@networked	Manual sync + ownership
@audio	VRC_SpatialAudioSource
@video	VRC_AVProVideoPlayer
@mirror	VRC_MirrorReflection
@avatar_pedestal	VRC_AvatarPedestal

VRChat-Specific Syntax

composition "MyCoolWorld" {
  environment {
    name: "My Cool World"
    spawn_point: [0, 0, 0]
    respawn_height: -10
    max_players: 32
  }

  // VRChat pickup template
  template "Pickup" {
    @grabbable
    geometry: "box"
    pickupable: true
    auto_hold: "auto_detect"
    proximity: 0.1
  }

  // Synced template (network replicated)
  template "NetworkedBall" {
    @grabbable
    @synced
    geometry: "sphere"
    sync_mode: "manual"
    owner_only: true
  }

  // Portal template
  template "WorldPortal" {
    geometry: "portal"
    world_id: "wrld_xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
    instance_type: "public"
  }

  object "Pickup" using "Pickup" {
    position: [0, 1, 0]
  }

  object "NetworkedBall" using "NetworkedBall" {
    position: [0, 2, 0]
  }

  object "WorldPortal" using "WorldPortal" {
    position: [5, 0, 0]
  }
}

Export Workflow

1. Write HoloScript (.hsplus)
        │
        ▼
2. Run: holoscript export --target vrchat
        │
        ▼
3. Open Unity with VRChat SDK
        │
        ▼
4. Import generated files to Assets/
        │
        ▼
5. Build & Test (VRChat SDK → Build & Test)
        │
        ▼
6. Upload to VRChat

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Unity Export (General)

For non-VRChat Unity projects using standard XR frameworks.

Prerequisites

1. Unity 2021.3+ (LTS recommended)
2. XR Plugin Management package
3. XR Interaction Toolkit (or Oculus/SteamVR SDK)

Quick Start

npm install @holoscript/unity-adapter

Programmatic Export

import { exportToUnity } from '@holoscript/unity-adapter';

const result = await exportToUnity(ast, {
  outputDir: './UnityProject/Assets/HoloScript',
  projectName: 'MyVRGame',
  xrFramework: 'xr-interaction-toolkit', // or 'oculus', 'steamvr'
});

XR Framework Options

Framework	Best For
xr-interaction-toolkit	Cross-platform (Quest, PC VR, AR)
oculus	Meta Quest optimization
steamvr	PC VR via SteamVR/OpenVR
none	Non-XR Unity projects

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Side-by-Side Comparison

Same HoloScript, Different Targets

Source (.hsplus):

composition "BallDemo" {
  template "Ball" {
    @grabbable
    geometry: "sphere"
    color: "#ff0000"
  }

  object "Ball" using "Ball" {
    position: [0, 1, 0]
  }
}

VRChat Export (UdonSharp):

using UdonSharp;
using VRC.SDKBase;
using VRC.Udon;

public class Ball : UdonSharpBehaviour
{
    [UdonSynced] private Vector3 position;

    void Start()
    {
        transform.position = new Vector3(0, 1, 0);
    }

    public override void OnPickup()
    {
        Networking.SetOwner(Networking.LocalPlayer, gameObject);
    }
}

Unity Export (C#):

using UnityEngine;
using UnityEngine.XR.Interaction.Toolkit;

public class Ball : MonoBehaviour
{
    private void Awake()
    {
        transform.position = new Vector3(0, 1, 0);
    }

    public void OnSelectEntered(SelectEnterEventArgs args)
    {
        Debug.Log($"{gameObject.name} grabbed");
    }
}

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Best Practices

1. Design for Multiple Targets

composition "CrossPlatformItem" {
  // Use standard traits that map to both VRChat and Unity
  template "Item" {
    @grabbable
    @physics
    geometry: "sphere"
  }

  object "Item" using "Item" {
    position: [0, 1, 0]
  }
}

2. Use Conditional Compilation

// VRChat-specific
@if target == "vrchat" {
  portal#spawn {
    world_id: "wrld_xxx"
  }
}

// Unity-specific
@if target == "unity" {
  teleporter#spawn {
    scene: "MainMenu"
  }
}

3. Test in Web First

The Three.js adapter provides instant preview:

// Fast iteration in browser
import { createWorld } from '@holoscript/three-adapter';

const world = createWorld({ container: document.body });
await world.loadFile('./scene.hsplus');
world.start();

Then export to Unity/VRChat when ready.

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CLI Commands

# Export to VRChat
holoscript export scene.hsplus --target vrchat --output ./VRChatProject

# Export to Unity
holoscript export scene.hsplus --target unity --output ./UnityProject/Assets

# Preview in browser first
holoscript dev scene.hsplus

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Troubleshooting

VRChat Export Issues

Issue	Solution
"UdonSharp not found"	Install UdonSharp via VCC
"SDK version mismatch"	Use Unity 2022.3.22f1
"Pickup not working"	Add Rigidbody, set isKinematic
"Sync not working"	Check ownership transfer

Unity Export Issues

Issue	Solution
"XRGrabInteractable missing"	Install XR Interaction Toolkit
"Namespace conflict"	Change projectName in config
"Prefab won't import"	Check Unity version compatibility

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See Also

• HoloScript Language Spec
• Traits Reference
• VRChat Creator Companion
• Unity XR Interaction Toolkit

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License

MIT - HoloScript packages are open source.