public Vector4f add(Vector4f vec, Vector4f result) {
        result.x = x + vec.x;
        result.y = y + vec.y;
        result.z = z + vec.z;
        result.w = w + vec.w;
        return result;
    }
<code>add</code> adds the values of a provided vector storing the
values in the supplied vector.

@param vec
           the vector to add to this
@param result
           the vector to store the result in
@return result returns the supplied result vector.
jme3-core/src/main/java/com/jme3/math/Vector4f.java