three-geo
three-geo is a three.js based geographic visualization library. Using three-geo, we can easily build satellite-textured 3D terrain models in near real-time by simply specifying GPS coordinates anywhere on the globe. The geometry of the terrain is based on the RGB-encoded DEM (Digital Elevation Model) provided by the Mapbox Maps API.
The terrain is represented by standard THREE.Mesh objects. This makes it easy for us to access underlying geometry/texture array and perform original GIS (Geographic Information System) experiments in JavaScript. (See Usage for how to programatically obtain those mesh objects).
Credits: this library has been made possible thanks to
- geo-related libraries (mapbox, Turfjs) and the Mapbox Maps API.
- peterqliu for informative 3D terrain-related articles and implementation.
Demo
live | source code)
1) examples/geo-viewer (This demo app includes features such as
- on-demand 3D terrain building (by a mouse click on the Leaflet map),
- real-time camera projection onto Leaflet (with oritentaion and HFoV indication),
- terrain interaction with a VR-like laser beam,
- measuring Euclidean distances between terrain points,
- auto camera orbiting around the custom z-axis.
Live:
-
https://w3reality.github.io/three-geo/examples/geo-viewer/io/index.html?lat=46.5763&lng=7.9904
-
https://w3reality.github.io/three-geo/examples/geo-viewer/io/index.html?lat=36.2058&lng=-112.4413
live | source code)
2) examples/heightmaps (This demo illustrates the relationship between a reconstructed 3D terrain and its underlying satellite/DEM tiles.
live | source code)
3) examples/flat (How to get a flattened view of the terrain by post-editing the underlying geometry.
4) examples/projection (live | source code)
How to register a new 3D object on top of the terrain based on its geographic location [latitude, longitude, elevation]
.
Setup
Installation
$ npm i three-geo
Loading
Script tag: use ThreeGeo
after
<script src="dist/three-geo.min.js"></script>
ES6:
import ThreeGeo from 'dist/three-geo.esm.js';
Usage
Here is an example of how to build a geographic terrain located at GPS coordinates (46.5763, 7.9904) in a 5 km radius circle. The terrain's satellite zoom resolution is set to 12. (The highest zoom value supported is 17.)
For standalone tests, use examples/simple-viewer (source code).
For use with NodeJS, do enable this isNode
option as well.
const tgeo = new ThreeGeo({
tokenMapbox: '********', // <---- set your Mapbox API token here
});
const terrain = await tgeo.getTerrainRgb(
[46.5763, 7.9904], // [lat, lng]
5.0, // radius of bounding circle (km)
12); // zoom resolution
const scene = new THREE.Scene();
scene.add(terrain);
const renderer = new THREE.WebGLRenderer({ canvas });
renderer.render(scene, camera);
three-geo
?
Who is using - jet-wasp - Three-geo as A-Frame component (source code)
- locus-pocus - A webapp to visualise your area using three-geo
API
In this section, we list three-geo
's public API methods, where origin
, radius
, and zoom
are parameters common to them:
-
origin
Array<number> Center of the terrain represented as GPS coordinates[latitude, longitude]
. -
radius
number Radius of the circle that fits the terrain. -
zoom
number (integer) Satellite zoom resolution of the tiles in the terrain. Select from {11, 12, 13, 14, 15, 16, 17}, where 17 is the highest value supported. For a fixed radius, higher zoom resolution results in more tileset API calls.
ThreeGeo
-
constructor(opts={})
Create a ThreeGeo instance with parameters.
-
async getTerrainRgb(origin, radius, zoom)
[ Added in v1.4 ]Return a THREE.Group object that represents a 3D surface of the terrain.
The group object contains an Array<THREE.Mesh> as
.children
. Each mesh corresponds to a partial geometry of the terrain textured with satellite images. -
async getTerrainVector(origin, radius, zoom)
[ Added in v1.4 ]Return a THREE.Group object that represents a 3D contour map of the terrain.
The group object contains an Array<THREE.Object3D> as
.children
. Each child object is either an extruded THREE.Mesh with.name
attribute prefixed bydem-vec-shade-<ele>-
, or a THREE.Line with.name
prefixed bydem-vec-line-<ele>-
(<ele>
is the height of each contour in meters). -
getProjection(origin, radius, unitsSide=1.0)
[ Example ]Return an object
{ proj, projInv, bbox, unitsPerMeter }
that includes transformation-related functions and parameters, where-
proj(latlng)
is a function that maps geo coordinateslatlng
(an array[lat, lng]
) to WebGL coordinates[x, y]
. -
projInv(x, y)
is a function that maps WebGL coordinates[x, y]
to geo coordinates[lat, lng]
. -
bbox
is an array[w, s, e, n]
that represents the computed bounding box of the terrain, wherew
(West) ande
(East) are longitudinal limits; ands
(South) andn
(North) are latitudinal limits. -
unitsPerMeter
is the length in WebGL-space per meter.
-
Legacy callback based API
-
getTerrain(origin, radius, zoom, callbacks={})
-
callbacks.onRgbDem
function (meshes) {} Implement this to request the geometry of the terrain. Called when the entire terrain's geometry is obtained.meshes
Array<THREE.Mesh> All the meshes belonging to the terrain.
-
callbacks.onSatelliteMat
function (mesh) {} Implement this to request the satellite textures of the terrain. Called when the satellite texture of each mesh belonging to the terrain is obtained.mesh
THREE.Mesh One of the meshes that's part of the terrain.
-
callbacks.onVectorDem
function (objs) {} Implement this to request the contour map of the terrain. Called when the contour map of the terrain is obtained.objs
Array<THREE.Object3D> Extruded meshes (THREE.Mesh objects with.name
attribute prefixed bydem-vec-shade-<ele>-
) and lines (THREE.Line objects with.name
attribute prefixed bydem-vec-line-<ele>-
), where<ele>
is the height of each contour in meters.
-
Build
After git clone
and cd
to the repository,
$ npm i
$ npm run build
Building on Windows
While npm run build
on Windows is confirmed to work (via GitHub's workflow with some tweaks), for better results, it is recommended to use WSL2 instead (thanks @sonicviz for reporting this).