This paper is aimed at 3D object understanding from 2D images, including ar
ticulated objects in active vision environment, using interactive, and inte
rnet virtual reality techniques. Generally speaking, an articulated object
can be divided into two portions: main rigid portion and articulated portio
n. It is more complicated that "rigid" object in that the relative position
s, shapes or angles between the main portion and the articulated portion ha
ve essentially infinite variations, in addition to the infinite variations
of each individual rigid portions due to orientations, rotations and topolo
gical transformations. A new method generalized from linear combination is
employed to investigate such problems. It uses very few learning samples, a
nd can describe, understand, and recognize 3D articulated objects while the
objects status is being changed in an active vision environment.