## 3 Rock 3D Structure Creation
### Three-Way Entrance and Three-Way Exit Seepage Simulation Study  
Figure 15 shows that the seepage velocity of the \"X + Y + Z\" multidirectional channel had a significant increase compared with the single channel seepage. The average velocity in the X direction in the \"X + Y + Z\" multidirectional channel seepage was 34.30 m/s, which was 91.14% higher than the average velocity of the X forward single channel seepage. The average velocity in the Y direction of the \"X + Y + Z\" multidirectional channel seepage was 34.87 m/s, which was 51.81% higher than the average velocity of the Y positive single channel seepage. The average velocity in the Z direction of the \"X + Y + Z\" multidirectional channel seepage was 33.89 m/s, which was 66.29% higher than the average velocity of the Z positive single channel seepage. The water flows in the X, Y, and Z directions affected each other, and part of the water entering from the positive direction of X flowed out from the negative direction of Y and the negative direction of Z. The water entering in the positive direction of Y and Z also had the same characteristics as the direction of X, and the water in the three directions, X, Y, and Z, flowed with each other. \begin{table}
\begin{tabular}{c c c c} \hline
**Entrance Surface** & **Entrance Velocity (m/s)** & **Exit Surface** & **Exit Velocity (m/s)** \\ \hline X + Y & 15.58 & X & 23.20 \\  & 30.92 & Y & 27.48 \\ \hline \end{tabular}
\end{table} 
Table 6: The average velocity distribution of the X and Y exit surfaces of the “X + Y” bidirectional channel seepage. \begin{table}
\begin{tabular}{c c c c c} \hline
**Entrance Surface** & **Permeability** & \multirow{2}{*}{**Percentage (\%)**} & \multirow{2}{*}{**Exit Surface**} & \multicolumn{2}{c}{**Permeability**} \\  & **(10\({}^{-3}\) μm2)** & & & **(10\({}^{-3}\) μm2)** & **Percentage (\%)** \\ \hline X & 337 & 43.31 & X & 391 & 50.33 \\ Y & 441 & 56.69 & Y & 386 & 49.67 \\ \hline \end{tabular}
\end{table} 
Table 5: The permeability of the X and Y exit surfaces of the “X + Y” bidirectional channel seepage. Compared with the seepage characteristic in the \"X + Y\" bidirectional channel, the seepage velocity and path of the \"X + Y + Z\" multidirectional channel underwent greater change. Affected by the seepage pressure in the Z direction, the seepage paths in the positive X and Y directions became shorter, and the seepage velocity increased significantly. For example, the \"X + Y\" bidirectional channel seepage had an average seepage velocity of 30.86 m/s, and the \"X + Y + Z\" multichannel seepage had an average seepage velocity of 34.35 m/s. The characteristics of the pressure field and velocity field of the \"X + Y\" and \"X + Y + Z\" multidirectional channel seepage simulations not only confirmed the characteristics of simulation research by [36; 37], but also the seepage characteristic of the research was more comprehensive. The velocity cloud diagram of the X-, Y-, and Z-direction cross-sections of the \"X + Y + Z\" multidirectional channel seepage is shown in Figure 16. Table 7 shows the velocity of each section of the \"X + Y + Z\" multidirectional channel seepage in the X, Y, and Z directions and the velocity of each section of the unidirectional channel. Figure 15: “X + Y + Z” multidirectional channel seepage velocity distribution. (**a**) Streamline diagram of velocity distribution. (**b**) Velocity distribution vector diagram. Figure 16: _Cont._  
The seepage velocities of different cross-sections in the X, Y, and Z directions are compared in Figure 16 with the seepage velocities of various cross-sections in the X, Y, and Z forward single channels. The seepage velocity in the three directions of the \"X + Y + Z\" multidirectional channel was significantly higher, and the velocity change range of each section was also changed.