geometric-functions poly2grid_untiled


  • poly2grid_untiled(polygon_data_item, gridunit)


The poly2grid_untiled function results in grid data-item with a relation to the domain-unit of the polygon_data_item

The resulting data item has:


This function is the same as poly2grid but writes singly threaded on a single mutable shadow tile that is then split into separate tiles after rendering all polygons. Compared to poly2grid, this poly2grid_untiled function will:

  • take longer to calculate (as it doesn’t process tiles in parallel),
  • use more memory (to store the intermediate mutable shadow tile),
  • but uses less CPU time (as polygons preparation is not repeated for each tile with which their bounding box intersects),
  • the results are independent of the actual tiling (which could not be always true for poly2grid as the conversion to a tile-local coordinate system might cause tiling-dependent flip-cases).

applies to

  • data item polygon_data_item with a wpoint, spoint, upoint, ipoint, fpoint or dpoint value-type
  • unit gridunit with a wpoint, spoint upoint, ipoint, fpoint, dpoint value type


  1. The composition type type of the polygon_data_item needs to be polygon.
  2. The domain-unit of the polygon_data_item must be of value type uint32.

since version



attribute<source/district> DistrictGrid (gridunit/gridcel_10m) := 
   poly2grid_untiled(Source/District/border, gridunit/gridcel_10m);

see also