The image is a screenshot from an engine detailed in the upcoming book
'Programming Role Playing Games with DirectX 8.0' written by myself, Jim
Adams. The engine allows 3-D models to move around within a pre-rendered 2-D
backdrop (ala Final Fantasy 7-10).
The demo (w/full source code) that comes with the book allows the model to
walk around, blocked by the various obsticals, as well as walking up and
down the stairs. The model, called Yodan, was created and used with
permission by Scarecrow and is freely downloadable from www.polycount.com (a
Half-life model). The book also details how to use Half-Life and other
format models in your own game.
Check out the book's web site at http://home.att.net/~rpgbook/ for more
details and some downloadable demos.