terrainGetPositionAt :: (String, Number, Number, Number) -> TerrainPosition
Create a TerrainPosition which represents the position at the x/y/z
coordinates within the terrain instance identified by the tag. The z
component does not need to be accurate. The function will project the position
to the closests surface.
Example
pos = terrianGetPositionAt 'default', 0.3, 0.7, 0.5