|Reported by:||dustymugs||Owned by:||dustymugs|
Taking a geometry and a raster, return a new XYM geometry resulting from overlaying the geometry on the raster and populating M with values from the raster.
geometry ST_Drape( rast raster, nband int, geom geometry, computed_vertices boolean DEFAULT TRUE )
Some things to think about before implementing...
- XYM or XYZ output geometry: Assuming the raster is DEM, units are typically meter or foot. If X/Y are degrees, populating Z in the DEM's units don't make sense. Maybe a function parameter flag indicating output should be XYZ or XYM?
- 3D geometry with rasters: The geometry is treated as 2D. Should pixel values be put into Z or M?
- computed_vertices: The returning geometry should be as detailed as the input raster. So, returning geometry will have the same vertices of the input geometry and possibly.
- Polygons: How to handle the interior of the polygon? Boundary is easy. Multipolygon? TIN?