A Generated Mesh
The vertex at row $r$ and column $c$ has index
\[i=r\cdot n + c\]
and position
\[\begin{array}{ll} x = 2\cdot\frac{c}{n-1}-1 \\ y = 0 \\ z = 2\cdot\frac{r}{n-1}-1 \\ \end{array}\]