/* create a grid of nodes (leaving points within the future patches blank) */
MapNode[][] nodeGrid = new MapNode[posGrid.sizeX()][posGrid.sizeZ()];
for (int x = 0; x < posGrid.sizeX(); x++) {
for (int z = 0; z < posGrid.sizeZ(); z++) {
if (x % PATCH_SIZE_POINTS == 0 || x == posGrid.sizeX() - 1
|| z % PATCH_SIZE_POINTS == 0 || z == posGrid.sizeZ() - 1) {
VectorXZ pos = posGrid.get(x, z);