# PyBullet Simulation Guide

## Standalone Mode (1 Terminal)

No ROS 2 required. Works on Windows, macOS, Linux:

```bash
source activate.sh
python standalone_simulation.py --pattern circular
```

## ROS 2 Mode (2 Terminals)

**Terminal 1 - Simulator:**
```bash
python simulation_host.py
```

**Terminal 2 - Controllers:**
```bash
python run_bridge.py --pattern circular
```

## Options

```bash
--pattern, -p   stationary, linear, circular, square, random
--speed, -s     Rover speed in m/s (default: 0.5)
--amplitude, -a Movement radius (default: 2.0)
```

## Remote Setup

**Machine 1:** `python simulation_host.py`
**Machine 2:** `python run_bridge.py --host <IP>`

## Sensors

| Sensor | Description |
|--------|-------------|
| IMU | Orientation, angular velocity |
| Altimeter | Altitude, vertical velocity |
| Velocity | Estimated velocity (x, y, z) |
| Camera | 320x240 downward JPEG |
| Landing Pad | Relative position |

## Configuration

Edit `config.py`:

```python
CONTROLLER = {
    "Kp_z": 0.5,
    "Kd_z": 0.3,
    "Kp_xy": 0.3,
    "Kd_xy": 0.2,
}
```

## Troubleshooting

**"Cannot connect to X server":**
```bash
xvfb-run python standalone_simulation.py
```

**Drone flies erratically:**
Reduce gains in `config.py`