Because you are working with points, the answer is "yes", barely...
create or replace function d3d(geometry, geometry) returns float as 'select sqrt((st_x($1)-st_x($2))^2 + (st_y($1)-st_y($2))^2 + (st_z($1)-st_z($2))^2)' language sql; select b.* from a join b on (st_dwithin(a.geom, b.geom, [distance]) and d3d(a.geom, b.geom) < [distance]); if st_dwithin worked in 3d the second clause would not be necessary, but it doesn't. neither to the indices, so it could be slow, if you have a lot of variation in z. P. On Thu, May 8, 2008 at 10:56 AM, Decarlo, Thomas R. (LARC-B702)[NCI INFORMATION SYSTEMS] <[EMAIL PROTECTED]> wrote: > I've got a question about processing 3D geometry data and I'm not sure > if the query functions in PostGIS can help me. > > I have two tables (A and B) of 3D point features in a Euclidean space. > I want to select all the points in B that are NOT within some distance > (S) of any of the points in A. > > Can I do this query using PostGIS? If yes, what would the query look > like? > > Thanks! > Thom > -- > Thom DeCarlo > ------------------------------------- > That Which Does Not Kill Me > Can Still Hurt Really Bad. > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
