id summary reporter owner description type status priority milestone component version resolution keywords cc
2327 [raster] ST_Drape Bborie Park Bborie Park "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.
Reference:
http://vterrain.org/Misc/draping.html
{{{
geometry ST_Drape(
rast raster, nband int,
geom geometry,
computed_vertices boolean DEFAULT TRUE
)
}}}
Some things to think about before implementing...
1. 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?
2. 3D geometry with rasters: The geometry is treated as 2D. Should pixel values be put into Z or M?
3. 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.
4. Polygons: How to handle the interior of the polygon? Boundary is easy. Multipolygon? TIN?" enhancement new medium PostGIS Fund Me raster master dmcclean