/hz-unity-meta-quest-ui

name: hz-unity-meta-quest-ui
license: Apache-2.0
description: Configures Unity UI for Meta VR and Horizon OS VR development — world-space canvases, TextMesh Pro setup, comfortable sizing, viewing distances, and interaction readiness.

Meta VR UI Setup

When to use this skill

Use this skill automatically when:

• Setting up a Canvas for VR
• Creating UI text with TextMesh Pro in a VR project
• Adding buttons, sliders, or other interactive UI in VR
• User reports pink/magenta text, unclickable buttons, or UI sizing issues in VR
• Configuring VR interaction (ray or poke) on a Canvas

Driving the Editor

Build the UI against an open Editor with `unity-cli` rather than hand-editing scene YAML — the Editor applies changes to the actual active scene.

unity status --format json          # look for state "ready"
unity command run_script --file AgentScripts/BuildUI.cs --entry BuildUI.Run --format json

Canvas construction is multi-component work, so it belongs in a `run_script` `.cs` file (kept **outside `Assets/`**, path relative to the project root) rather than a chain of single commands. Add `--dry_run true` to compile-check a script before it mutates the scene — but read the verdict from **`data.result.success`**: a compile failure still returns outer `success: true` and exit code `0`, with the errors in `data.result.diagnostics`. Connecting, `--project-path`, and Safe Mode recovery are in the **`unity-cli`** skill; MCP equivalents are in [references/unity-mcp-fallback.md](references/unity-mcp-fallback.md).

Single-property reads and writes are cheaper as direct commands than as a script:

unity command get_component_properties --target MenuUI --type Canvas --format json
unity command set_transform --target MenuUI --position "[0,1.5,2]" --format json
unity command find_gameobjects --name MenuUI --format json

Array parameters take a **JSON array in one argument** (`--position "[0,1.5,2]"`). Space- or comma-separated components are rejected with `INVALID_COMMAND_ARGS`. Note `set_transform` writes **local** position — see the **unity-placement** skill for parented canvases.

Prerequisite: TMP Essential Resources

Before creating ANY VR UI, verify TMP resources are imported:

unity command find_assets --name "LiberationSans SDF" --format json

A `data.result.count` of `0` means they are missing — use the **tmp-resources** skill before proceeding.

Step 1: Create World Space Canvas

// AgentScripts/BuildUI.cs
using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.UI;

public static class BuildUI
{
    public static string Run()
    {
        // Adapt the name to match your canvas (e.g., "MainMenu", "SettingsUI")
        var go = new GameObject("MenuUI");
        var canvas = go.AddComponent<Canvas>();
        canvas.renderMode = RenderMode.WorldSpace;

        go.AddComponent<GraphicRaycaster>();

        // Remove CanvasScaler — not appropriate for VR
        var scaler = go.GetComponent<CanvasScaler>();
        if (scaler != null)
            Object.DestroyImmediate(scaler);

        var rt = go.GetComponent<RectTransform>();
        rt.localScale = new Vector3(0.001f, 0.001f, 0.001f);
        rt.sizeDelta = new Vector2(1920f, 1080f);
        rt.position = new Vector3(0f, 1.5f, 2f);

        Undo.RegisterCreatedObjectUndo(go, "Create VR Canvas");
        EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
        return $"Created VR Canvas '{go.name}'. Scale: {rt.localScale}, Size: {rt.sizeDelta}, Position: {rt.position}";
    }
}

Persist it when the shape is right:

unity command save_scene --format json

Canvas rules

• **Render Mode**: Always World Space. Screen Space modes break stereo rendering.
• **Scale**: 0.001 on all axes (1 unit in canvas = 1mm in world).
• **CanvasScaler**: Remove it. Physical size is controlled by world scale, not screen adaptation.
• **Distance**: Place 1.5-3m from user. Never closer than 0.5m. Max 5m for readable text.
• **Physical size formula**: `Canvas sizeDelta * scale = meters`. Example: 1920 * 0.001 = 1.92m wide.

Step 2: Create child UI elements

All child elements (panels, buttons, text) must follow these rules:

• **localScale**: Always `[1, 1, 1]`. Never scale children to compensate for canvas scale.
• **localPosition.z**: Always `0`. Children must sit on the canvas plane.
• **Size control**: Use `RectTransform.sizeDelta` and anchors, never scale.

// AgentScripts/BuildPanel.cs
using TMPro;
using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.UI;

public static class BuildPanel
{
    public static string Run()
    {
        // Replace "MenuUI" with the actual canvas name used in Step 1
        var canvas = GameObject.Find("MenuUI");
        if (canvas == null) return "ERROR: Canvas 'MenuUI' not found.";

        // Panel
        var panel = new GameObject("ButtonPanel");
        panel.transform.SetParent(canvas.transform, false);
        var panelRT = panel.AddComponent<RectTransform>();
        panelRT.localScale = Vector3.one;
        panelRT.sizeDelta = new Vector2(800f, 600f);
        var panelImg = panel.AddComponent<Image>();
        panelImg.color = new Color(0.1f, 0.1f, 0.1f, 0.95f);
        panelImg.raycastTarget = false;

        var layout = panel.AddComponent<VerticalLayoutGroup>();
        layout.spacing = 50f;
        layout.padding = new RectOffset(80, 80, 100, 100);
        layout.childAlignment = TextAnchor.MiddleCenter;

        // Button
        var btnGO = new GameObject("StartButton");
        btnGO.transform.SetParent(panel.transform, false);
        var btnRT = btnGO.AddComponent<RectTransform>();
        btnRT.localScale = Vector3.one;
        btnRT.sizeDelta = new Vector2(400f, 120f);
        var btnImg = btnGO.AddComponent<Image>();
        btnImg.color = new Color(0.2f, 0.6f, 1f, 1f);
        btnGO.AddComponent<Button>();

        // B