Map Tiles

Generates orthographic map tile images at multiple zoom levels for use with web map viewers (e.g., Leaflet). Includes an ImGui control panel with progress tracking.

Overview

util_maptiles renders the current level from a top-down orthographic camera at multiple zoom levels, producing a tile pyramid suitable for slippy map viewers. Exports tile images as PNG, a metadata JSON file, and an optional navgraph overlay.

Extension path: lua/ge/extensions/util/maptiles.lua

Exports (M)

Internals

Tile Generation Parameters

Rendering Setup

Before generation, rendering settings are adjusted for quality:

• TS::detailAdjust → 20000 (max mesh detail)
• Terrain::lodScale → 0.00001 (max terrain detail)
• groundCoverScale → 8 (dense vegetation)
• Shadows disabled (sunsky.castShadows = false)
• Shadow texture minimized (texSize = 64)

Settings are restored after completion.

Tile Grid

For each zoom level, tile size = baseTileSize / 2^zoomLevel:

• Tiles are generated left-to-right, top-to-bottom.
• Each tile uses an orthographic RenderView positioned above its center.
• Terrain height is determined by raycasting at tile center.

Output Structure

tiles/
  {levelName}/
    {zoom}/{x}/{y}.png
  metadata.json
  navgraph.json (optional)

Metadata

{
  "levelName": {
    "baseTileSize": 1000,
    "basePixelSize": 512,
    "maxZoomLevel": 5,
    "terrainSizeUnits": 4000,
    "tileGrid": {
      "0": { "tileSizeUnits": 1000, "pixelSize": 512, "tilesX": 4, "tilesY": 4 }
    }
  }
}

Navgraph Export

exportNavgraph() converts the road network into polygon data:

• Each road link becomes a quad (4 points) sized by node radii.
• Coordinates are transformed to tile-space.
• Color-coded by drivability level.
• Output: tiles/navgraph.json.

ImGui Interface

• Progress grid: Color-coded tile status (grey=pending, yellow=current, green=done).
• Preview: Live render view of the current tile.
• ETA: Estimated time remaining based on average per-tile time.
• Debug panel: 3D world toggle, zoom level selector, manual tile stepping.

How It Works

1. Load: extensions.load('util_maptiles').
2. Open the ImGui window and click "Start Tile Generation".
3. The system iterates through zoom levels 0→5, rendering each tile.
4. Tiles are saved as PNG files in the output directory.
5. Metadata JSON is written on completion.

Lua Examples

-- Load the map tile utility
extensions.load('util_maptiles')

-- The UI handles all interaction
-- Navgraph can be exported separately via the UI button

-- Coordinate conversion (for custom overlay integration):
-- Game coords → export coords: flip Y, offset by bounds, scale by pixel/tile ratio

Additional Exports

• M.onUpdate - (undocumented)