Study on MMO in Visual Simulation Application - Advances in Image and Graphics Technologies - page 244

(a)Tanks 6x magnification (b) Soldiers 2x magnification

View

(c) Soldiers 1x magnifica-
tion View

View

Fig. 3 . Tanks and soldiers each 3D view display

Interaction of entities will change accordingly at this time, as figure 4 showing.

Fig. 4 . Entities interaction after Interaction range of visual field partition

If it needs to transmit 20 data packages in one interaction between this three entities
(the entity doesn't need to interact with itself), there are 120 packages according to the
mode of figure 1 in one data interaction, and just 20 packages according to the mode of
figure 4. Therefore, by using mode of visual field partition interaction range, we can
obviously reduce the simulation data flow on network. Furthermore, the entity scale is
bigger and the effect is more evident.
(2) Using Dead Reckoning technology to decrease the communication frequency
During the network peak time, network often works with delay and jam. If players
always wait for the updating message back from the server in large multi-people game,
then player would loose the interest for the game. Under this situation, we should use
some measures to reduce the negative effect which were brought by the network delay to
remove network delay result. Dead Reckoning is a method to ensure the fluency of game
under bad network status. Dead Reckoning means that if updating data from the server
does not arrive now, client reckons next state based on the current state, of course these
state should be continued. The forecasting position of players is just the simple case. In
this case, the client can conserve the resent N position and its related time. When N>3,
we can use the twice function to make interpolation computing, so that it can forecast the
position at a new time by twice equation. If N=3, there are three position in client, the
sequence according to time is P0, P1, P2, the corresponding time is T0, T1, T2

。

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