See also space filling curves like the hilbert curve and Google's S2... https://docs.google.com/presentation/d/1Hl4KapfAENAOf4gv-pSngKwvS_jwNVHRPZTTDzXXn6Q/view#slide=id.i0
On Tue, Oct 31, 2017 at 8:09 AM, Stadin, Benjamin < benjamin.sta...@heidelberg-mobil.com> wrote: > To me this proposal looks too complicated for practical application in > it‘s current form. I think the surface model (or a „default“ model) and > related algorithms should be part of the proposal. > > I needed to solve some of the problems they mention for our 3d rendering > engine (store vector data of multiple projections in an indexed storage > and separate vector storage, projection and visible projection when > rendering) as well as for parallel data processing of large data sets. > > I found that systems which use ellipsoidal polygons on the surface model > of the earth impractical for a variety of reasons: Image data and rendering > systems mostly deal with rectangular tiles, there are commonly accepted > (but not standardized) properties like zoom levels and tile sizes which > many software adheres to, and also algorithm complexity and implementation > effort. > > I ended up with an adaptation of the MODIS grid for our application ( > https://modis-land.gsfc.nasa.gov/MODLAND_grid.html) so that cells (which > are equal area in MODIS) are of the same length as OSM / Web Mercator tiles > (at the equator), also considering zoom levels. > > I think there is a real need for such concept, but in my opinion there > needs to be a default model and algorithms in order to be relevant. > > Best > Ben > > Von meinem iPad gesendet > > Am 31.10.2017 um 13:40 schrieb Roberto Ribeiro <robertofi...@gmail.com>: > > I too took that understanding from the text, Ari. I'll read the specs > later, but since they mention a lot Big Data and the raster <> vector > integration, I it is akin to a geometry collection, but encompassing a > wider range of data types, and arranged in a pyramid/r-tree -esque > environment for faster processing. > > If so, it's not an entirely novel idea (Esri's File GDB is mostly that, as > well as the entire CAD modelling), but one that would be interesting to > have an open standard for. > > 2017/10/31 午前4:23 "Ari Jolma" <ari.jo...@gmail.com>: > >> That also caught my eye. The text sounds a bit like marketing talk but >> maybe there is something. >> >> From a quick look my understanding is that the idea is to create a grid >> that divides the whole earth into cells of similar shape in a sequence of >> increasing cell size. And that sounds to me like a new idea. >> >> Any other thoughts? Did I get the idea right? >> >> Best, >> >> Ari >> >> >> Helmut Kudrnovsky kirjoitti 29.10.2017 klo 01:16: >> >>> Fyi >>> >>> http://www.opengeospatial.org/pressroom/pressreleases/2656 >>> >>> "The goal of DGGS is to enable rapid assembly of spatial data without the >>> difficulties of working with projected coordinate reference systems. The >>> OGC >>> DGGS Abstract Specification standard defines the conceptual model and a >>> set >>> of rules for building highly efficient architectures for spatial data >>> storage, integration and analytics. ....." >>> >>> >>> >>> ----- >>> best regards >>> Helmut >>> -- >>> Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html >>> _______________________________________________ >>> gdal-dev mailing list >>> gdal-dev@lists.osgeo.org >>> https://lists.osgeo.org/mailman/listinfo/gdal-dev >>> >> >> _______________________________________________ >> gdal-dev mailing list >> gdal-dev@lists.osgeo.org >> https://lists.osgeo.org/mailman/listinfo/gdal-dev > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev > > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev > -- -- http://schwehr.org
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