UV-Packer has been released in version 1.10 for Autodesk 3ds Max.

UV-Packer automatically redistributes all UV charts in a UV map for optimal fit. Do you often find yourself spending a lot of time to rearrange charts generated by pelting or do you need to modify UV maps because the proportions of the UV space or the size of the required padding have changed?

UV-Packer does it with a single click of a button.
It can also rescale the separate UV charts depending on the mesh surface area to even out the pixel distribution across different parts of the mesh.