The initial quad tree leaf boundaries line up with the GDO screen boundaries exactly, causing the client browsers to download and parse more leaves than necessary.
For example, suppose the black box represents the boundaries of a screen, and the red boxes represent the boundaries of quad tree leaves:
Since the boundaries line up exactly, the leaves corresponding to all of the red boxes will be downloaded and parsed, which causes rendering time to increase. It is highly unlikely for this situation to occur after the user zooms or pans.
The initial quad tree leaf boundaries line up with the GDO screen boundaries exactly, causing the client browsers to download and parse more leaves than necessary.
For example, suppose the black box represents the boundaries of a screen, and the red boxes represent the boundaries of quad tree leaves:
Since the boundaries line up exactly, the leaves corresponding to all of the red boxes will be downloaded and parsed, which causes rendering time to increase. It is highly unlikely for this situation to occur after the user zooms or pans.