float currentXgrid = 0;
float currentZgrid = 0;
for ( unsigned int m = 0; m <= grid_Size; m++ )
{
    u = currentXgrid;
    v = currentZgrid;

    currentXgrid += 0.1;
    if ( currentXgrid > 1  )
    {
         currentXgrid = 0; 
         currentZgrid += 0.1;
     }
}