# geodata

> Handles pathfinding, collision detection, and line-of-sight calculations for the L2J gameserver.
Use when: implementing movement validation, checking LOS for skills/attacks, adding dynamic objects (doors/fences), debugging player movement issues, or optimizing pathfinding performance

- Author: valeriybaranyshyn-pixel
- Repository: valeriybaranyshyn-pixel/Tales-of-Aden
- Version: 20260202145225
- Stars: 0
- Forks: 0
- Last Updated: 2026-02-06
- Source: https://github.com/valeriybaranyshyn-pixel/Tales-of-Aden
- Web: https://mule.run/skillshub/@@valeriybaranyshyn-pixel/Tales-of-Aden~geodata:20260202145225

---

---
name: geodata
description: |
  Handles pathfinding, collision detection, and line-of-sight calculations for the L2J gameserver.
  Use when: implementing movement validation, checking LOS for skills/attacks, adding dynamic objects (doors/fences), debugging player movement issues, or optimizing pathfinding performance
allowed-tools: Read, Edit, Write, Glob, Grep, Bash
---

# Geodata Skill

The GeoEngine provides terrain collision, pathfinding, and line-of-sight (LOS) calculations using pre-computed `.l2d` geodata files. The system uses a hierarchical structure: World → Regions (176 total) → Blocks (256×256 per region) → Cells (8×8 per block). Each cell stores height data and NSWE movement flags indicating allowed directions.

## Quick Start

### LOS Check

```java
// GeoEngine.java:518-585
if (GeoEngine.getInstance().canSeeTarget(attacker, target)) {
    // Target is visible, can attack/cast
}
```

### Movement Validation

```java
// GeoEngine.java:972-997
if (GeoEngine.getInstance().canMoveToTarget(ox, oy, oz, tx, ty, tz)) {
    // Direct line movement is possible
} else {
    // Use pathfinding instead
    List<Location> path = GeoEngine.getInstance().findPath(ox, oy, oz, tx, ty, tz, true);
}
```

### Height Correction

```java
// Get correct Z coordinate for spawning/teleporting
short correctZ = GeoEngine.getInstance().getHeight(worldX, worldY, worldZ);
```

## Key Concepts

| Concept | Usage | Example |
|---------|-------|---------|
| Cell | Smallest unit, 16×16 game units | `GeoStructure.CELL_SIZE = 16` |
| NSWE flags | 8-bit directional movement mask | `CELL_FLAG_N = 0x08, CELL_FLAG_S = 0x04` |
| Block types | Flat, Complex, Multilayer | `BlockFlat` = single height, `BlockMultilayer` = bridges |
| Dynamic blocks | Runtime-modifiable for doors | `addGeoObject(door)` converts block type |
| LOS cache | 1.5s TTL per target | Reduces redundant LOS calculations |

## Common Patterns

### AI Movement Check

```java
// L2AttackableAI.java - Check if monster can reach target
if (!GeoEngine.getInstance().canMoveToTarget(
    getActor().getX(), getActor().getY(), getActor().getZ(),
    target.getX(), target.getY(), target.getZ())) {
    // Find alternative path or abandon chase
}
```

### Skill Range Validation

```java
// Before casting, verify LOS exists
if (!GeoEngine.getInstance().canSeeTarget(caster, target)) {
    caster.sendPacket(SystemMessageId.CANT_SEE_TARGET);
    return false;
}
```

## See Also

- [patterns](references/patterns.md)
- [workflows](references/workflows.md)

## Related Skills

- See the **ai-system** skill for AI movement integration
- See the **l2j-gameserver** skill for server architecture
- See the **configuration-management** skill for geoengine.properties settings
- See the **java** skill for L2J coding conventions