Terrain Tile Specification

SimVector serves continuous global elevation data as compressed 24-bit PNG tiles using the standard Terrain-RGB encoding scheme. It is engineered for low-bandwidth 3D terrain rendering, hypsometric tinting (color-relief), and dynamic hillshading.

Metadata

Property	Value
Schema Name	SimVector Global Elevation 90m
HTTPS Endpoint	https://tiles.simvector.net/global_elevation_90m/{z}/{x}/{y}.png
Protocol Endpoint	simvector://global_elevation_90m/{z}/{x}/{y}.png
Source Resolution	3 arc-second (~90m nominal grid spacing)
Format / Encoding	Terrain-RGB (24-bit PNG)
Tile Size	512 x 512 px
Zoom Range	Min: 0 / Max: 10
Spatial Bounds	[-180.0, -89.9511287, 180.0, 85.0511287] (Global WGS84)
Elevation Unit	Meters MSL

MapLibre GL JS Integration

1. Source Definition

map.addSource('elevation-dem', {
  type: 'raster-dem',
  tiles: ['simvector://global_elevation_90m/{z}/{x}/{y}.png'],
  tileSize: 512,
  maxzoom: 10,
  bounds: [-180, -89.9511287798066, 180, 85.0511287798066]
});

2. Hillshade Layer

map.addLayer({
  id: 'vfr-hillshade',
  type: 'hillshade',
  source: 'elevation-dem',
  paint: {
    'hillshade-exaggeration': 0.3,
    'hillshade-shadow-color': '#21160e',
    'hillshade-highlight-color': '#ffffff',
    'hillshade-accent-color': '#000000'
  }
});

3. 3D Mesh Terrain Rendering

To enable native 3D mesh rendering in MapLibre:

map.setTerrain({
  source: 'elevation-dem',
  exaggeration: 1.0
});

Tile Size Requirement

Always set tileSize: 512 when consuming SimVector DEM tiles. Standard 256px configurations may cause sampling mismatches and visual elevation tearing along tile boundaries.

Example: VFR Color Banding

The following example demonstrates how to apply standard VFR sectional hypsometric tinting to the DEM tile source using MapLibre's color-relief layer type. Altitude bands and color specifications are derived from the FAA's Aeronautical Chart User's Guide.

Altitude Color Bands

Elevation Range (MSL)	Elevation Range (Meters)	Hex Color	Visual Band
Below Sea Level – 1,000 ft	-70m to 304m	#cce3b6	Light Lowland Green
1,000 ft – 2,000 ft	305m to 609m	#dcedc2	Pale Green
2,000 ft – 3,000 ft	610m to 913m	#fff7cb	Soft Yellow
3,000 ft – 5,000 ft	914m to 1,523m	#f6e398	Warm Yellow
5,000 ft – 7,000 ft	1,524m to 2,133m	#e8cb83	Low Mountain Tan
7,000 ft – 9,000 ft	2,134m to 2,742m	#ddb07e	Ochre
9,000 ft – 12,000 ft	2,743m to 3,657m	#edaa6e	High Mountain Brown
12,000 ft – 19,633 ft+	3,658m to 5,983m	#b27d35	Dark Alpine Brown

Layer Implementation Snippet

Place this layer above your background fill and below hydrology or aeronautical overlays:

map.addLayer({
  id: 'vfr-terrain-tint',
  type: 'color-relief',
  source: 'elevation-dem',
  paint: {
    'color-relief-color': [
      'interpolate',
      ['linear'],
      ['elevation'],
      
      // Below Sea Level to 1,000 ft (-70m to 304m)
      -70, '#cce3b6',
      0,   '#cce3b6',
      304, '#cce3b6',

      // 1,000 ft to 2,000 ft (305m to 609m)
      305, '#dcedc2',
      609, '#dcedc2',

      // 2,000 ft to 3,000 ft (610m to 913m)
      610, '#fff7cb',
      913, '#fff7cb',

      // 3,000 ft to 5,000 ft (914m to 1523m)
      914,  '#f6e398',
      1523, '#f6e398',

      // 5,000 ft to 7,000 ft (1524m to 2133m)
      1524, '#e8cb83',
      2133, '#e8cb83',

      // 7,000 ft to 9,000 ft (2134m to 2742m)
      2134, '#ddb07e',
      2742, '#ddb07e',

      // 9,000 ft to 12,000 ft (2743m to 3657m)
      2743, '#edaa6e',
      3657, '#edaa6e',

      // 12,000 ft to 19,633 ft (3658m to 5983m)
      3658, '#b27d35',
      5983, '#b27d35'
    ],
    'color-relief-opacity': 1.0
  }
});