Unity TextMeshPro - Professional Text Rendering

Overview

TextMeshPro (TMPro) is Unity's advanced text rendering solution using Signed Distance Field (SDF) technology for resolution-independent, high-quality text with minimal performance overhead.

Foundation Required: unity-csharp-fundamentals (TryGetComponent, FindAnyObjectByType), unity-ui (UI systems, Canvas, UGUI)

Core Topics:

• SDF font asset creation and configuration
• Dynamic vs static font assets
• Rich text formatting and styling
• Material presets and text effects
• Performance optimization patterns
• Localization and dynamic text handling

Quick Start

Basic Text Setup

using TMPro;
using UnityEngine;

public class TextController : MonoBehaviour
{
    [SerializeField] private TMP_Text mDisplayText;

    void Start()
    {
        mDisplayText.text = "Hello, World!";
        mDisplayText.fontSize = 36;
        mDisplayText.color = Color.white;
    }
}

TMP_Text vs TextMeshProUGUI vs TextMeshPro

// TMP_Text - Base class, use for serialization (works with both)
[SerializeField] private TMP_Text mText;

// TextMeshProUGUI - Canvas UI text (most common)
[SerializeField] private TextMeshProUGUI mUiText;

// TextMeshPro - 3D world space text (MeshRenderer)
[SerializeField] private TextMeshPro mWorldText;

Rich Text Formatting

// Basic formatting
text.text = "<b>Bold</b> and <i>Italic</i>";
text.text = "<size=48>Large</size> and <size=24>Small</size>";
text.text = "<color=#FF0000>Red</color> text";

// Advanced formatting
text.text = "<mark=#FFFF00AA>Highlighted</mark>";
text.text = "H<sub>2</sub>O and E=mc<sup>2</sup>";
text.text = "<s>Strikethrough</s> and <u>Underline</u>";

// Sprite embedding
text.text = "Score: 100 <sprite=0>";

Component Selection Guide

Font Asset Best Practices

Font Asset Types

Static Font Asset:
- Pre-generated character set
- Best performance (no runtime generation)
- Use for: Known character sets, optimized builds

Dynamic Font Asset:
- Runtime character generation
- Flexible but slower initial render
- Use for: Localization, user input, unknown characters

Creating Optimal Font Assets

1. Font Asset Creator (Window > TextMeshPro > Font Asset Creator)

   • Set appropriate Atlas Resolution (1024x1024 for basic, 2048x2048 for CJK)
   • Use "Custom Character List" for known character sets
   • Enable Multi Atlas Textures for large character sets

2. Sampling Point Size: Use highest size that fits atlas (better quality)

3. Padding: 5-9 for normal use, higher for effects (outline, glow)

Performance Guidelines

Text Update Optimization

// BAD: Frequent text changes trigger mesh rebuild
void Update()
{
    scoreText.text = $"Score: {score}"; // Rebuilds every frame
}

// GOOD: Update only when value changes
private int mLastScore = -1;

void Update()
{
    if (score != mLastScore)
    {
        mLastScore = score;
        scoreText.text = $"Score: {score}";
    }
}

// BETTER: Use SetText for formatted updates (less allocation)
void UpdateScore(int score)
{
    scoreText.SetText("Score: {0}", score);
}

Memory-Efficient Patterns

// Use StringBuilder for complex text construction
private readonly StringBuilder mSb = new StringBuilder(256);

void BuildComplexText()
{
    mSb.Clear();
    mSb.Append("Player: ");
    mSb.Append(playerName);
    mSb.Append(" | Score: ");
    mSb.Append(score);
    displayText.SetText(mSb);
}

// Prefer SetText with parameters over string interpolation
text.SetText("{0}/{1}", currentHP, maxHP);  // Less GC
// Instead of
text.text = $"{currentHP}/{maxHP}";         // More GC

Material Presets

// Apply material preset at runtime
[SerializeField] private Material mHighlightMaterial;
[SerializeField] private Material mNormalMaterial;

void Highlight(bool active)
{
    mText.fontMaterial = active ? mHighlightMaterial : mNormalMaterial;
}

// Modify material properties
mText.fontMaterial.SetFloat(ShaderUtilities.ID_OutlineWidth, 0.2f);
mText.fontMaterial.SetColor(ShaderUtilities.ID_OutlineColor, Color.black);

Reference Documentation

Fundamentals

Core TextMeshPro concepts:

• SDF technology explanation
• Font asset creation workflow
• Character sets and fallback fonts
• Sprite assets integration
• Style sheets usage

Performance Optimization

Optimization techniques:

• Mesh geometry optimization
• Dynamic batching strategies
• Font atlas memory management
• Text update minimization patterns
• Profiling text rendering

Advanced Patterns

Advanced usage patterns:

• Custom shaders and effects
• Text animation techniques
• Localization integration
• Typewriter effects
• Link and event handling

Key Principles

1. Use TMP_Text for References: Base class works with both UI and 3D text
2. Prefer SetText() over .text: Reduces GC allocations for dynamic values
3. Update Only When Changed: Avoid unnecessary mesh rebuilds
4. Choose Appropriate Font Assets: Static for performance, Dynamic for flexibility
5. Batch Similar Text: Group text with same material for draw call reduction

Common Anti-Patterns

// AVOID: Creating new materials per text instance
text.fontMaterial = new Material(text.fontMaterial); // Memory leak risk

// AVOID: Updating text in Update() without change check
void Update() { text.text = score.ToString(); } // Constant rebuild

// AVOID: Excessive rich text nesting
text.text = "<b><i><color=#FF0000><size=48>...</size></color></i></b>";

// AVOID: Dynamic fonts for static content
// Use pre-generated static font assets instead

Platform Considerations

• Mobile: Use static font assets, minimize atlas size, avoid complex effects
• WebGL: Pre-load font assets, avoid dynamic font generation
• VR/AR: Consider text readability, use larger fonts, avoid thin outlines

Integration with Other Skills

• unity-ui: TextMeshPro integrates with Canvas and UI Toolkit
• unity-performance: Text rendering impacts draw calls and memory
• unity-mobile: Font asset optimization critical for mobile
• unity-async: Async font loading with Addressables