Function setTerrainActive

setTerrainActive(active): void
JMap.Map.setTerrainActive

Returns true if the map is associated with a terrain.
Parameters
- active: boolean
  whether to activate or deactivate the terrain
Returns void
Throws
Error is no terrain is available

Example
```
// returns true if the map is associated with a terrain
if(JMap.Map.isTerrainAvailable()){
   JMap.Map.setTerrainActive(true)
}else{
   console.log("no terrain available")
}
```