Glimmer

GPU-accelerated shimmer loading placeholders for Unity UI.

Installation

Via OpenUPM (Recommended)

Install via OpenUPM CLI:

openupm add com.iraklichkuaseli.glimmer

Or add the package via OpenUPM scoped registry in Packages/manifest.json:

{
  "scopedRegistries": [
    {
      "name": "OpenUPM",
      "url": "https://package.openupm.com",
      "scopes": ["com.iraklichkuaseli"]
    }
  ],
  "dependencies": {
    "com.iraklichkuaseli.glimmer": "1.0.2"
  }
}

Via Git URL

Add this line to your Packages/manifest.json:

{
  "dependencies": {
    "com.iraklichkuaseli.glimmer": "https://github.com/irakli/glimmer.git"
  }
}

Or install via Package Manager:

1. Open Window → Package Manager
2. Click the + button
3. Select "Add package from git URL"
4. Enter: https://github.com/irakli/glimmer.git

Requirements

• Unity 2022.3 or later
• Unity 6000+ for async ShowAsync/HideAsync
• TextMeshPro

Features

• GPU shimmer - Shader-based animation, zero CPU overhead
• Explicit targets - Assign Graphics in Inspector, use "Refresh Targets" to auto-discover
• Live preview - See effect in Editor without Play mode
• Non-destructive - Original materials restored on Hide()

Usage

Basic

[SerializeField] private GlimmerGroup glimmer;

public void Load()
{
    glimmer.Show();

    // ... fetch data ...

    glimmer.Hide();
}

Async (Unity 6000+)

public async Awaitable LoadAsync()
{
    await glimmer.ShowAsync(0.2f);  // Fade in

    var data = await FetchDataAsync();
    DisplayData(data);

    await glimmer.HideAsync(0.3f);  // Fade out
}

Runtime Configuration

// Change colors at runtime
glimmer.SetColors(
    baseColor: new Color(0.9f, 0.9f, 0.9f, 0.5f),
    shimmerColor: new Color(1f, 1f, 1f, 0.5f)
);

// Change animation parameters
glimmer.SetAnimation(
    duration: 1.5f,   // Shimmer cycle duration
    angle: 25f,       // Shimmer angle (-45 to 45)
    width: 0.25f      // Shimmer band width (0.1 to 0.5)
);

Components

Component	Purpose
GlimmerGroup	Main controller - add as sibling after text targets
GlimmerElement	Per-element overrides (ignore, corner radius)

GlimmerElement

Add to any target Graphic for per-element control:

Property	Description
IgnoreGlimmer	Exclude this element from the shimmer effect
CornerRadius	Override corner radius (when enabled)

Setup

Create via menu: GameObject > UI > Glimmer Group

Important: Place GlimmerGroup after any sibling TextMeshPro elements.

Container
├── Image
├── TMP_Text      ← text target (index 1)
├── GlimmerGroup  ← must be after text (index 2+)
└── Background    ← other elements can be after

Why? Unity UI renders siblings in hierarchy order. For TextMeshPro elements, GlimmerGroup renders its own mesh quads as placeholders (the text is made transparent). If GlimmerGroup is before a text target, the placeholder will be obscured.

The Inspector will warn you if GlimmerGroup is incorrectly positioned and offer a "Move After Text Targets" button to fix it.

API Reference

GlimmerGroup

Method	Description
Show()	Activates glimmer effect
Hide()	Hides glimmer, restores materials
Toggle()	Toggles between Show/Hide
ShowAsync(duration, ct)	Fade-in animation (Unity 6000+)
HideAsync(duration, ct)	Fade-out animation (Unity 6000+)
SetColors(base, shimmer)	Change colors at runtime
SetAnimation(duration, angle, width)	Change animation parameters
Initialize()	Pre-warm glimmer (call during screen setup)
Refresh()	Force refresh of all materials
RefreshTargets()	(Editor) Re-discover Graphics in hierarchy
ClearTargets()	(Editor) Clear all target Graphics

Properties

Property	Type	Description
IsShowing	bool	Whether glimmer is currently visible
TargetGraphics	IReadOnlyList<Graphic>	List of target Graphics

Events

Event	Description
StateChanged	Fired when IsShowing changes (parameter: bool isShowing)
PropertiesChanged	Fired when colors or animation parameters change

Advanced Usage

Async Cancellation

ShowAsync and HideAsync support cancellation tokens. If cancelled mid-animation, they throw OperationCanceledException:

var cts = new CancellationTokenSource();

try
{
    await glimmer.ShowAsync(0.5f, cts.Token);
}
catch (OperationCanceledException)
{
    // Animation was cancelled - call Hide() to reset state
    glimmer.Hide();
}

Material Lifecycle

GlimmerGroup manages materials non-destructively:

• Original materials and colors are saved during Show()
• Cached glimmer materials are reused across Show/Hide cycles
• Original materials are restored on Hide()
• All cached materials are destroyed on component destruction

Component Enable/Disable

If GlimmerGroup is disabled while showing, it will automatically resume showing when re-enabled.

Pre-warming

Call Initialize() during screen setup to avoid first-show latency:

private void Start()
{
    glimmer.Initialize(); // Pre-load shader, ready for instant Show()
}

Package Structure

com.iraklichkuaseli.glimmer/
├── package.json             # UPM package manifest
├── README.md                # This file
├── CHANGELOG.md             # Version history
├── LICENSE.md               # MIT License
├── Runtime/
│   ├── GlimmerGroup.cs      # Main controller component
│   ├── GlimmerElement.cs    # Per-element overrides
│   ├── IrakliChkuaseli.Glimmer.asmdef
│   └── Shaders/
│       └── Glimmer.shader   # GPU shimmer shader
├── Editor/
│   ├── GlimmerGroupEditor.cs    # Custom inspector
│   ├── GlimmerElementEditor.cs  # Element inspector
│   └── IrakliChkuaseli.Glimmer.Editor.asmdef
├── Icons/
└── Tests/
    ├── Editor/
    └── Runtime/

Troubleshooting

Glimmer not showing on TextMeshPro elements

Problem: Text placeholders are invisible or behind other elements.

Solution: Ensure GlimmerGroup is positioned after all TMP_Text targets in the hierarchy. The Inspector shows a warning and "Move After Text Targets" button if this is misconfigured.

Shader not found error

Problem: Console shows "Shader 'UI/Glimmer/Shimmer' not found".

Solution:

1. Verify the package is fully imported (check Runtime/Shaders/Glimmer.shader exists)
2. Try reimporting the package via Package Manager
3. Check for shader compilation errors in the Console

Materials not restoring after Hide()

Problem: Original materials look different after calling Hide().

Solution: This can happen if you modify target Graphics while glimmer is showing. Call Refresh() after modifying targets, or call Hide() before making changes.

Async methods not available

Problem: ShowAsync and HideAsync don't exist.

Solution: These methods require Unity 6000+. On older Unity versions, use synchronous Show()/Hide() methods.

Corner radius looks wrong

Problem: Rounded corners have artifacts or look cut off.

Solution: Corner radius is automatically clamped to half the minimum rect dimension. For very small elements, reduce the corner radius.

License

MIT