A subdivision surface is a surface that has been divided into more faces while retaining the object's general shape. You perform subdivision to add detail to an object, or to smooth it out.

3ds Max supports two kinds of subdivision surfaces:

• The HSDS modifier provides hierarchical subdivision surfaces, which you can use to add fine detail to an object.
• The MeshSmooth modifier and TurboSmooth modifier provide smoothing.

  Related closely to these are the Subdivision Surface rollout controls for editable poly objects, with which you can subdivide a surface without the need for a modifier.

  NoteThese controls are not available with the Edit Poly modifier.

The latter type works best as a finishing tool for models.