An octree-based animated geometry compression method was
proposed [25]. Figure 2 shows the encoding process of this
approach. To encode the current frame, the reconstructed version
of the previous frame needs to be available in the encoder. A set
of motion vectors is generated to represent the differential motion
between the previously reconstructed frame and the current frame,
and these motion vectors are only stored in the leaf nodes of an
octree. Octree is then encoded for further data reduction. The first
frame in the animation sequence is encoded differently using
intra-frame encoding method. An encoded animation sequence
consists of an intra-coded first frame followed by an encoded
octree for each of subsequent frames. The size of encoded octree
is significantly smaller than the corresponding frame in the
animation sequence. The vertex positions for each frame can be
reconstructed in the decoder side by the corresponding octree and
the previous reconstructed frame in the sequence.