Currently the grid implementation is done using the Isoextractor Tool. When an isometric DGN is to be created a pseudo COG is calculated by adding up the coordinates of all ports and dividing that by the number of ports. The grid that contains this point will then become the active grid and its local coordinate system is used to rotate the isometric to the grid. When multiple grids are defined at the same location but with different elevations (platforms) the grid is chosen where the COG has the smallest positive Z- distance to the grid. Depending on the configuration, the coordinate labels can be output either relative to the grid coordinate system, relative to a column intersection, or both.

For a grid line intersection to be valid, the point in question should be able to project physically on both a NORTH and EAST gridline. Physically means the projected point is between the start and end points of the gridline. If column based dimensioning is configured and no valid intersection can be found, then the local grid coordinate system is used.