Zoomable map
The Zoomable Map example allows you to create a runtime zoomable and pannable map. This example is a starting point for creating a traditional web-based zoomable map.
Place custom markers
Placing custom markers on zoomable and non-zoomable maps is mostly a similar process, with one exception. Since the zoom level of a zoomable map can change at runtime, the marker positions need to be updated in every frame. The Zoomable Map example handles this with a script called SpawnOnMap.
SpawnOnMap provides an outline of placing custom markers. It uses the Start() function to calculate initial marker positions, then uses Update() to update those positions every time the map changes (either from zooming or panning).
...
void Start()
{
_locations = new Vector2d[_locationStrings.Length];
_spawnedObjects = new List<GameObject>();
for (int i = 0; i < _locationStrings.Length; i++)
{
var locationString = _locationStrings[i];
_locations[i] = Conversions.StringToLatLon(locationString);
var instance = Instantiate(_markerPrefab);
instance.transform.localPosition = _map.GeoToWorldPosition(_locations[i], true);
+ instance.transform.localScale = new Vector3(_spawnScale, _spawnScale, _spawnScale);
_spawnedObjects.Add(instance);
}
}
private void Update()
{
int count = _spawnedObjects.Count;
for (int i = 0; i < count; i++)
{
var spawnedObject = _spawnedObjects[i];
var location = _locations[i];
spawnedObject.transform.localPosition = _map.GeoToWorldPosition(location, true);
}
}
...
Using the SpawnOnMap example script
To use the SpawnOnMap script, add it as a Component to a Map GameObject. Below is a description of the variables.
| Variables | Description |
|---|---|
| Map | Map object on which to place custom markers. |
| Location Strings | List of locations in latitude, longitude where the markers will spawn. |
| Spawn Scale | Scale of spawned markers. Applied as uniform scale in all directions. |
| Custom Prefab | Prefab that will be spawned on the map as the marker. |
Understand quadtree tile provider
Web Mercator tile services use a quadtree structure to provide tiles at different zoom levels. The QuadTreeTileProvider script leverages this quadtree structure to request tiles for the area of interest. QuadTreeTileProvider uses the location in latitude, longitude, the camera's viewport, and the map's zoom level to determine the area of interest.
QuadTreeTileProvider provides a way to create a zoomable map without moving the camera in the scene. The map's root and individual UnityTile objects are scaled appropriately to provide zooming ability, like traditional web-based maps. QuadTreeTileProvider also provides an API call to update the map when the location and/or zoom level changes.
Benefits and limitations
Using this map gives you a runtime, zoomable map instead of a static map. It takes care of the tile scaling and map scaling for you so you can look at a map at different zoom levels. It also decouples the camera from the map for zooming.
By default this example only provides a top-down 2D view of the map, without vector data.