public float getValue(int i) {
        return hdata[i];
    }
Returns the height value at the given index.

zero index is top left of map,
getWidth()*getHeight() index is lower right

@param i The index
@return an arbitrary height looked up from the heightmap

@throws NullPointerException If isLoaded() is false
jme3-terrain/src/main/java/com/jme3/terrain/GeoMap.java