ExtendSurface
 
Thanks to

Pior "pior" Oberson
for the original concept

IllusionCatalyst ExtendSurface extends an Editable Poly surface from its border. If no elements are selected, all borders are extended.

  1. Select a set of Edges or border elements
  2. Run IC.ExtendSurface
  3. Drag Up to increase surface extension, down to decrease
  4. Drag Up/down pressing CTRL to adjust extension slant
  5. Right click to exit the command or left click to start another extension

Note: Undo can be performed only from Main toolbar button or by pressing CTRL+Z after stopping the tool.
Autodesk 3ds Max 9+
Additional requirement for 3ds Max release 9 only
AVGuard MAXScript Extension Package 9.0.0 by Larry Minton
Download — version 0.2 — 2009.12.09 — 4.53 KBytes
Discussion thread on Polycount forum