[postgis-users] 3D geometries

[Havard Tveite]

Hi,

For "ST_SetMFromRaster(geom, rast)", I think it would be
better to only add the Z/M value to the points of the input
geometry.  Those that want to do something like ST_Densify
should do that as a separate preprocessing step.
This would give the user more control of the process (the
user may want tunnels and bridges).

Håvard

On 3/13/2012 7:47 PM, Stephen V. Mather wrote:
> Hi Pierre,
>
> I could try my hand at this as a PL/pgSQL function.  Can't help with the
> C++... :)
>
> I'm thinking ST_Densify ala Paul deriving the densification from the cell
> size of the input raster, then use st_dumppoints and st_intersects, and then
> reconstruct to 3D line (or am I thinking too low level to be efficient).
>
> Best,
> Steve
>
>
> Stephen Mather
> Geographic Information Systems (GIS) Manager
> (216) 635-3243
> svm at clevelandmetroparks.com
> clevelandmetroparks.com
>
>
>
>
>
> -----Original Message-----
> From: Pierre Racine [mailto:Pierre.Racine at sbf.ulaval.ca]
> Sent: Tuesday, March 13, 2012 2:22 PM
> To: svm at clevelandmetroparks.com; PostGIS Users Discussion
> Subject: RE: [postgis-users] 3D geometries
>
> Hi Stephen,
>
> It would certainly be very nice to have a generic function doing it:
>
> SELECT  ST_SetMFromRaster(geom, rast)  geom
> FROM mylines, myrast
> WHERE ST_Intersects(geom, rast)
>
> Pierre
>
>> -----Original Message-----
>> From: postgis-users-bounces at postgis.refractions.net [mailto:postgis-users-
>> bounces at postgis.refractions.net] On Behalf Of Stephen V. Mather
>> Sent: Tuesday, March 13, 2012 1:43 PM
>> To: postgis-users at postgis.refractions.net
>> Subject: [postgis-users] 3D geometries
>>
>> Hi All,
>>
>>                  Any special considerations for turning a 2D multi-line
> geometry into a
>> 3D geometry using a DEM as a RASTER within PostGIS?  Has anyone played in
>> this arena?
>>
>>
>>
>> Thanks,
>> Steve
>>
>>
>>
>> http://www.clemetparks.com/images/esig/cmp-ms-90x122.pngStephen Mather
>> Geographic Information Systems (GIS) Manager
>> (216) 635-3243
>>
>> svm at clevelandmetroparks.com
>> clevelandmetroparks.com<http://www.clemetparks.com/>