How can I calculate 3D distance with OS10g

Question

Hi,
How can i calculate 3D distance between two objects using OS 10g?
Thanks,

Answer 1

If you have two 3d points you can:
Make them into a line string
Linear reference the 3d line string
The length of the 3d line string is the distance between the points
3d linear referencing is not supported for geodetic (non-cartesian) data.
In 11g of course the story changes drastically.
Here is a simple example:
create or replace function points3dDistance(geom1 sdo_geometry,geom2 sdo_geometry)
return number deterministic as
geom sdo_geometry;
length number;
begin
-- creating a 3d line segment
  geom := sdo_geometry(3002,null,null,sdo_elem_info_array(),sdo_ordinate_array());
-- not checking, but should be cartesian coordinate system
-- also geom1 and geom2 coordinate systems must match
  geom.sdo_srid := geom1.sdo_srid;
-- creating a line segment from two points
  geom.sdo_elem_info.extend(3);
  geom.sdo_elem_info := sdo_elem_info_array(1,2,1);
  geom.sdo_ordinates.extend(6);
-- if production i would check first for sdo_ordinates/elem info
-- and make sure point data with the right number or ordinates
-- since only demo assume input data comes from sdo_point in geom1 and geom2
  geom.sdo_ordinates(1) := geom1.sdo_point.x;
  geom.sdo_ordinates(2) := geom1.sdo_point.y;
  geom.sdo_ordinates(3) := geom1.sdo_point.z;
  geom.sdo_ordinates(4) := geom2.sdo_point.x;
  geom.sdo_ordinates(5) := geom2.sdo_point.y;
  geom.sdo_ordinates(6) := geom2.sdo_point.z;
-- Now convert to lrs3d and get the length
  return sdo_lrs.measure_range_3d(sdo_lrs.convert_to_lrs_geom_3d(geom));
end;
select points3dDistance(
  sdo_geometry(3001,41048,sdo_point_type(5000,5000,0),null,null),
  sdo_geometry(3001,41048,sdo_point_type(5000,6000,1000),null,null))
from dual;