Opened 6 years ago

Last modified 3 years ago

#1168 new enhancement

[raster] ST_AsRaster ability to render more complex types

Reported by: robe Owned by: dustymugs
Priority: low Milestone: PostGIS Future
Component: raster Version: trunk
Keywords: Cc:

Description

I have to admit I really love this new feature. One thing that would make this even nicer is if it can render more complex types such as Curved geometries, TINS, and PolyhedralSurfaces?. I presume this is more of a GDAL enhancement than a PostGIS change. Am I correct in assuming that it's pure GDAL and a possibly newer library in the future may be able to just work with an upgrade of GDAL library.

Which brings me to the second question of how far away is GDAL from being able to do this. I know for example MapServer in 6.0 now supports rendering of PostGIS curves (though haven't tested), but not sure if that is built into mapserver (I presume it is).

BTW started putting pictures in doc for raster. I'm just putting them in for now instead of having them rendered, I have a small ASP.NET app I'm building to demonstrate these functions which I'll share later as a tutorial.

Change History (9)

comment:1 Changed 6 years ago by dustymugs

Summary: ST_AsRaster ability to render more complex types[raster] ST_AsRaster ability to render more complex types

I don't believe OGR supports curved geometries or any of the newer geometry types. From the GDAL-dev mailing list:

http://osgeo-org.1803224.n2.nabble.com/Curve-support-in-OGR-td3091607.html

Yes to assuming it is pure GDAL/OGR. Specifically, PostGIS passes a WKB representation of the geometry to the OGR function OGR_G_CreateFromWkb. So, if and when GDAL supports curved geometries, TINs and Polyhedral Surfaces, we should be able to make use of it automatically.

comment:2 Changed 5 years ago by dustymugs

Owner: changed from pracine to dustymugs
Priority: mediumlow

comment:3 Changed 5 years ago by dustymugs

Status: newassigned

comment:4 Changed 5 years ago by pracine

Milestone: PostGIS Raster FuturePostGIS Future

comment:5 Changed 5 years ago by dustymugs

Milestone: PostGIS FuturePostGIS GDAL

comment:6 Changed 4 years ago by dustymugs

Status: assignednew

comment:7 Changed 4 years ago by dustymugs

I've been thinking more about the rasterization of geometries of all types and in the end, I get to the conclusion that PostGIS raster should do its own rasterization. Conceptually, rasterizing a geometry isn't that hard.

comment:8 Changed 4 years ago by robe

hmm really. That would solve MANY problems. e.g. there aren't too many tools that can take curved geometries natively so people are often forced to do ST_CurveToLine etc which is in many cases less than wonderful.

This might call for a funding campaign.

comment:9 Changed 3 years ago by dustymugs

Milestone: PostGIS GDALPostGIS Future

Due to the issue discussed in #2516 (and the fact that Frank had to undo work on GDAL for us), PostGIS may need to implement its own rasterizer.

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