Real-Time SLAM Visualization in Flutter

SLAM, or Simultaneous Localization and Mapping, enables a robot to build a map while estimating its own position. Flutter can provide an interactive real-time visualization layer for SLAM data.

Understanding the SLAM Pipeline

A robot may use:

LiDAR
Cameras
IMUs
Wheel encoders

The system produces:

Sensor Data
     |
     v
SLAM Algorithm
     |
     +--> Robot Position
     +--> Robot Orientation
     +--> Environment Map

Typical ROS 2 Topics

A robotics backend may provide:

/map
/odom
/scan
/tf

These messages can be transformed into application-friendly data before reaching Flutter.

Flutter Architecture

ROS 2
   |
   v
SLAM Gateway
   |
   v
WebSocket
   |
   v
Flutter App
   |
   +--> Map
   +--> Robot Position
   +--> Navigation Path

Creating a Map Point

class MapPoint {
  final double x;
  final double y;

  MapPoint({
    required this.x,
    required this.y,
  });
}

Visualizing the Map

Flutter's CustomPainter is useful for high-performance rendering:

class SlamPainter extends CustomPainter {
  final List<MapPoint> points;

  SlamPainter(this.points);

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint();

    for (final point in points) {
      canvas.drawCircle(
        Offset(point.x, point.y),
        2,
        paint,
      );
    }
  }

  @override
  bool shouldRepaint(covariant SlamPainter oldDelegate) {
    return true;
  }
}

Rendering the Robot

canvas.save();

canvas.translate(robotX, robotY);
canvas.rotate(robotYaw);

canvas.drawCircle(
  Offset.zero,
  10,
  Paint(),
);

canvas.restore();

Handling Continuous Updates

SLAM data can update frequently. To maintain performance:

Avoid rebuilding unnecessary widgets
Use efficient painting
Process large transformations in isolates
Throttle non-critical updates
Render only visible regions

Adding Map Interaction

InteractiveViewer(
  child: CustomPaint(
    size: Size.infinite,
    painter: SlamPainter(points),
  ),
)

This allows users to zoom and pan through the environment.

Conclusion

Real-time SLAM visualization gives operators and developers valuable insight into how a robot understands its environment. Flutter provides the rendering and interaction tools needed to build responsive robotics dashboards.