Databases Reference
In-Depth Information
Figure 11: Examples of image compositions.
Figure 12: Example of a new scene.
the avatar, he/she can input another key (e.g., 'f') assigned to the 'rotate to left'
operation by which the picture is changed as shown in (c). In addition, if the user
inputs 't' several times to step forward, he/she obtains the scene shown in (d),
which means the direction of the avatar's step is changed. An example of key
configurations is 't' to go forward, 'f' to rotate to the left, 'h' to rotate to the right,
and 'b' to go backward.
In Figure 11(a), if the user repeats going forward and the avatar comes out of
a predefined floor region, i.e., the bottom side of the trapezoid shown in Figure
10, the scene automatically changes to another one, as shown in Figure 12. This
figure where the view point and the direction of the scene are different from
those of Figure 11(a). This scene is constructed in a similar manner to the scene
shown in Figure 11, where the background image, the trapezoid region, and the
linkage information are different. Note that, in the situation shown in Figure
12, if a user turns back and moves to the back, the scene again changes back to
Figure 11(a), where the avatar appears with his backside image in front of the
scene.
In each picture in Figures 11 and 12, there are two or three arrows at the right
top area. These arrows represent the directions to which other scenes are linked
from the scene. Upward, downward, leftward, and rightward arrows, respectively,
link the scenes to the back, front, left, and right of the scene.
HTML, JavaScript, and Java are used to describe scenes that can be displayed
on a normal WWW browser. In each scene, four URLs at most are attached to
represent the front, back, right, and left neighbors of the scene. Of course, an
attached URL is not necessarily an IBNR scene, i.e., it can be a normal WWW
