# 🏔️ 2.5D TERRAIN SYSTEM - COMPLETE DOCUMENTATION

## 📋 OVERVIEW

Complete 2.5D terrain system with procedural hills, height-based collision, and visual polish.

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## ✅ PHASE 1: HEIGHT GENERATION & VISUALIZATION (COMPLETED)

### Implementation:
- **Height Generation:** Perlin noise (0.05 frequency) generates smooth hills
- **Height Range:** 0-5 discrete levels
- **Visual Effects:**
  - **Tint:** `0x666666` (dark valleys) → `0xffffff` (bright peaks)
  - **Scale:** `1.0x` → `1.5x` (50% size increase on peaks)
  - **Y-Offset:** `0px` → `-75px` (massive elevation)

### Code Location:
- **Generation:** `TerrainSystem.js` - `generateChunk()` line ~504
- **Visualization:** `TerrainSystem.js` - `updateCulling()` line ~1031

---

## ✅ PHASE 2: WALKABILITY CONSTRAINTS (COMPLETED)

### Implementation:
- **Height-Aware Collision:** Can't walk over height difference > 1
- **Cliff Detection:** Checks `Math.abs(toHeight - fromHeight) > 1`
- **Console Feedback:** Logs "🏔️ Blocked by cliff!"

### Code Location:
- **Collision Check:** `TerrainSystem.js` - `isSolid(x, y, fromX, fromY)` line ~1262

---

## 🎨 PHASE 3: VISUAL POLISH (OPTIONAL)

### Planned Features:

#### 1. **Cliff Edge Sprites**
```javascript
// Detect cliff edges (height diff > 1)
if (heightDiff > 1) {
    // Add cliff edge sprite between tiles
    const edgeSprite = this.add.sprite(x, y, 'cliff_edge');
    edgeSprite.setRotation(angleToNeighbor);
}
```

#### 2. **Shadow Effects**
```javascript
// Add shadow to lower tiles near cliffs
const shadowAlpha = Math.min(heightDiff * 0.2, 0.6);
const shadow = this.add.rectangle(x, y, tileWidth, tileHeight, 0x000000, shadowAlpha);
```

#### 3. **Gradient Blending**
```javascript
// Smooth color transitions between heights
const neighborAvgHeight = (h1 + h2 + h3 + h4) / 4;
const blendedTint = interpolateColor(currentTint, avgTint, 0.3);
```

---

## 🎮 USAGE

### Reset World (New Seed):
```javascript
// In browser console (F12):
localStorage.clear();
// Refresh → New procedural world with hills!
```

### Test Height System:
```javascript
const scene = window.gameState.gameScene;
const tile = scene.terrainSystem.getTile(50, 50);
console.log('Height:', tile.height); // 0-5
```

### Test Collision:
```
1. Walk around the map
2. Try to climb steep hills (height diff > 1)
3. Console: "🏔️ Blocked by cliff!"
```

---

## 📊 CURRENT STATUS

| Feature | Status | Description |
|---------|--------|-------------|
| Height Generation | ✅ Complete | Procedural hills with Perlin noise |
| Visual Height | ✅ Complete | Tint + Scale + Y-offset |
| Walkability | ✅ Complete | Height-based collision |
| Cliff Edges | ⏳ Optional | Visual borders (Phase 3) |
| Shadows | ⏳ Optional | Shadow effects (Phase 3) |
| Gradients | ⏳ Optional | Smooth blending (Phase 3) |

---

## 🔧 CUSTOMIZATION

### Adjust Height Intensity:
```javascript
// In TerrainSystem.js - generateChunk()
const heightNoise = this.noise.noise(x * 0.05, y * 0.05);
const rawHeight = (heightNoise + 1) * 2.5; // Change 2.5 to 5.0 for more extreme (0-10 range)
```

### Adjust Visual Effects:
```javascript
// In TerrainSystem.js - updateCulling()
const tintValue = 0x666666 + (height * 0x333333); // Adjust contrast
const scaleBonus = 1.0 + (height * 0.1); // Adjust size (0.1 = 10% per level)
const elevationOffset = -(height * 15); // Adjust elevation (15px per level)
```

### Adjust Walkability:
```javascript
// In TerrainSystem.js - isSolid()
if (heightDiff > 1) { // Change to 2 for more permissive, 0 for stricter
    return true; // Blocked
}
```

---

## 🐛 TROUBLESHOOTING

### Hills not visible?
1. Clear localStorage: `localStorage.clear()`
2. Refresh page
3. Check console for "🏔️ HEIGHT GENERATION" logs

### Can walk through cliffs?
1. Ensure player movement uses `terrainSystem.isSolid(x, y, fromX, fromY)` with 4 parameters
2. Check console for "🏔️ Blocked by cliff!" messages

### Tiles look glitchy?
1. Reduce elevation offset (try `height * 10` instead of `* 15`)
2. Reduce scale bonus (try `height * 0.05` instead of `* 0.1`)

---

## 📚 FILES MODIFIED

- `src/systems/TerrainSystem.js` - Height generation & visualization
- `docs/HEIGHT_SYSTEM_PLAN.md` - Implementation plan
- `docs/2.5D_TERRAIN_GUIDE.md` - This file

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**Implementation Date:** 2025-12-14  
**Status:** Phase 1-2 Complete, Phase 3 Optional  
**Author:** Antigravity AI Assistant