11.11.3 Additional Information Included in this Construction

This construction also includes additional geometric information on:

• the orientation of the coordinate lines (K direction)
• the shape of the pillars
• whether geometry has been defined for each cell and pillar

• colocation information on the coordinate line nodes

For the nodes along each coordinate line, there are #CoordinateLine x (NKL-1) Boolean values, which indicate whether the nodes are colocated. When describing the continuity of the nodes along each K edge, the count depends upon the topology of the grid. For example, for an IJK grid, the count will be 4 x NI x NJ x NKL, where the first index indicates that there are 4 edges for an IJ column. Ordering is shown in Figure 11.11.3-1 , and is chosen to be identical to the natural ordering for an unstructured column-layer grid.

Figure 11.11.3-1 RESQML IJ node ordering.

• For an IJK grid, the RESQML IJ node ordering within a column of the grid starts at the () = (0,0) corner and then increases first  then : (0,0), (1,0), (1,1), (0,1). For the “nodes are colocated on K edge” element, the colocation direction follows this node ordering.

• For an IJ grid, there are 4 Boolean values indicating colocation between (0,0) and (1,0), between (1,0) and (1,1), and so on. As shown in Figure 11.11.3-1 , this may appear to be either a clockwise or counter-clockwise direction when viewed in a spatial (XY) context, but at the indexing level the two diagrams are identical. The RESQML grid description includes mandatory parity information and K direction information, from which the spatial orientation may be inferred, but there is no direct specification of a clockwise or counter-clockwise data ordering.