On Mar 24, 2011, at 10:52 PM, Pierre Racine wrote:
Pierre,
My goal is to define the way leading from a point coverage to a
raster. Something like ST_Interpolate("pointgeomtable",
"rastercolumn") -> raster. What would be the step leading to that?
I guess we have everything now to store a Delaunay Triangulation as
polyhedral surfaces right?
Hum yes and no, in fact it depends :)
As i said the TIN model is designed for a feature model storage (CIM
use case),
so in a single cell, a reasonable small TIN (i.e thousands of points
is fine
or even more, but not a whole LIDAR Coverage triangulation)
If we want to handle this use case, i think
we have to add a way to split and aggregate a big TIN into several
small ones
(as i recall it should be the way Oracle Spatial handle it)
Then from this polyhedral surface we can derive a raster...
Maybe a first ST_AsDelaunayTriangulation(geom) could be an aggregate
SET function returning a set of triangle...
Yes, if you produce a set of Triangles rather than a single huge TIN,
it could works with the current TIN implementation.
Question: is it something liblas could already handle ?
and maybe ST_Interpolate(polyhedral surfaces) could be an aggregate
function that would aggregate those triangle into a raster?
--
Olivier
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