Your right, it can be done with the current function. IŽll explain a little better. With the current function you will see if the object fits within the region of x, y, z. I proposed you use another function, but to only search through axis z, which would mean 77% faster and mostly concerned with seperating regions by height. I proposed this for the increased speed it would have allowed for. Although, as you have said, you can currently do this, however 77% slower because you are looking between x, y and z.