Database Reference
In-Depth Information
Movement begins (“
enter
”) when velocity goes from zero to any other value (even
if it is smaller than the basic velocity unit) and the opening angle goes from fi xed to
any other size.
•
Thus, in sum, in the representation and storage of motion, there is no need to actually
have the time bits, since we can compute time from sampling frequency. That is, using
either 3, 5, or 7 bits is suffi cient for the
motion byte
to store motion in accordance with the
relevant joint degrees of freedom.
Motion Storage
We view the motion database as a three-dimensional cube. This view is not new and
is found in the temporal oriented model of data (TOMOD) (Ariav, 1986; Ozsoyoglu &
Snodgrass, 1995; Tansel et al., 1993; Etzion, 1998). Applying this view, the sets of the seven
motion bits defi ned above may be seen as a series of two-dimensional tables (a cube) giving
a motion database. The cube's measurements are as follows:
•
Objects axis
- the creature's limbs axis.
•
Characteristics/ features axis
- the 7-bit axis.
•
Time axis
- points on this axis represent the different moments at which motion was
sampled, producing the basic motion data.
It is therefore possible to view such a cube as a collection of seven two-dimensional
tables, each table depicting the current state of one particular characteristic (the state of
one of the seven bits), all through the time axis (i.e., the sampling process), for each of the
objects (i.e., the creature's limbs). This is illustrated in Figure 3.
Figure 4 illustrates four motion databases built from 3-bit motion bytes. All examples
assume the following constants:
Figure 3: Motion database cube
