# 🏔️ HEIGHT SYSTEM & 2.5D TERRAIN IMPLEMENTATION PLAN

## 📋 OVERVIEW

Transforming flat pixel-art terrain into 2.5D with procedural hills and elevation.

---

## 🎯 PHASE 1: HEIGHT GENERATION (IMPLEMENTING NOW)

### Changes:
1. **Add height property to tiles** (already exists in terrainTypes)
2. **Generate height using 2nd Perlin noise layer**
3. **Visual height representation:**
   - Tint (darker = lower, lighter = higher)
   - Scale (higher tiles = slightly bigger)
   - Y-offset (elevation visual)

### Code Changes:

**TerrainSystem.js - generateChunk():**
```javascript
// NEW: Height noise (separate from terrain type noise)
const heightNoise = this.noise.noise(x * 0.05, y * 0.05);
const elevationHeight = Math.floor((heightNoise + 1) * 2.5); // 0-5 range

// Store height in tile
this.tiles[y][x] = {
    type: tileType,
    height: elevationHeight, // NEW!
    solid: false
};
```

**TerrainSystem.js - updateCulling() rendering:**
```javascript
// Apply visual height effects
const tile = this.tiles[y][x];
const height = tile.height || 0;

// 1. Tint (darker low, lighter high)
const tintValue = 0xffffff - (height * 0x111111);
sprite.setTint(tintValue);

// 2. Scale (subtle)
const scaleBonus = 1 + (height * 0.02);
sprite.setScale(scaleBonus);

// 3. Y-offset (elevation)
const yOffset = -(height * 4);
sprite.y += yOffset;
```

---

## 🎨 VISUAL RESULTS:

```
Before (Flat):
████████████
████████████
████████████

After (Hills):
    ▓▓▓▓        ← Height 4 (lighter, higher)
  ▒▒▒▒▒▒▒▒      ← Height 3
░░░░░░░░░░░░    ← Height 2
████████████    ← Height 0 (valleys, base)
```

---

## 🚀 NEXT STEPS (PHASE 2):

1. **Walkability constraints**
   - Can't walk over height diff > 1
   - Pathfinding with elevation

2. **Smooth transitions**
   - Slope tiles between heights
   - Gradient blending

3. **Cliff edges**
   - Visual edge sprites
   - Shadow effects

---

## 📊 CURRENT STATUS:

- ✅ TerrainTypes have height property
- ✅ Perlin noise available
- ⏳ Height generation (implementing)
- ⏳ Visual rendering (implementing)
- ❌ Walkability (Phase 2)
- ❌ Slope transitions (Phase 2)

---

**Implementation Date:** 2025-12-14  
**Status:** In Progress  
**Files Modified:** TerrainSystem.js