29.5 SDO_PC_PKG.CREATE_CONTOUR_GEOMETRIES
Format
SDO_PC_PKG.CREATE_CONTOUR_GEOMETRIES( pc IN SDO_PC, sampling_resolution IN NUMBER, elevations IN SDO_ORDINATE_ARRAY, region IN SDO_GEOMETRY ) RETURN SDO_GEOMETRY_ARRAY;
or
SDO_PC_PKG.CREATE_CONTOUR_GEOMETRIES( pc_flat_table IN VARCHAR2, srid IN NUMBER, sampling_resolution IN NUMBER, elevations IN SDO_ORDINATE_ARRAY, region IN SDO_GEOMETRY ) RETURN SDO_GEOMETRY_ARRAY;
or
SDO_PC_PKG.CREATE_CONTOUR_GEOMETRIES( pc IN SDO_PC, sampling_resolution IN NUMBER, elevations_min IN NUMBER, elevations_interval IN NUMBER, elevations_max IN NUMBER, region IN SDO_GEOMETRY ) RETURN SDO_GEOMETRY_ARRAY;
or
SDO_PC_PKG.CREATE_CONTOUR_GEOMETRIES( pc_flat_table IN VARCHAR2, srid IN SDO_PC, sampling_resolution IN NUMBER, elevations_min IN NUMBER, elevations_interval IN NUMBER, elevations_max IN NUMBER, region IN SDO_GEOMETRY ) RETURN SDO_GEOMETRY_ARRAY;
Description
Generates contour lines for a point cloud.
Parameters
- pc
-
Point cloud object for which to generate contour lines.
- sampling_resolution
-
A numeric value that determines the grid cell height and width in the coordinate reference system of the point cloud. The smaller the number, the more detailed are the resulting contour geometries.
The process of the contour generation is grid-based. The points within a grid cell get averaged. This means:
-
Two slightly different point clouds may result in the same contours, as long as the grid cells yield the same averages.
-
The number of vertices and smoothness of the contour lines is a direct function of the resolution.
-
- elevations
-
An array of elevations for which contours should be generated.
- elevations_min
-
The starting elevation value in a set of equidistant elevations for which contours should be generated.
- elevations_interval
-
The interval to use for elevation values between
elevations_min
andelevations_max
when generating coutours.For example, if
elevations_min
is 100,elevations_max
is 150, andelevations_interval
is 10, then coutours are generated for elevations 100, 110, 120, 130, 140, and 150. - elevations_max
-
The ending elevation value in a set of equidistant elevations for which contours should be generated.
- region
-
A window (within the extent of the point cloud) further restricting the region within which the contour lines should be generated.
Usage Notes
This function returns an array of SDO_GEOMETRY contours. The sequence of contours within the array is the same as the sequence in the elevations
input parameter or in the computed values based on the elevations_min
, elevations_max
, and elevations_interval
input parameters. Each contour is a multiline string.
Contours enclosing higher elevations are oriented counterclockwise (like outer rings). Contours enclosing lower elevations are oriented clockwise (like inner rings).
Modeling Solids describes how to use point clouds to model solids.
Examples
The following example creates contour lines from a a specified a point cloud object.
SELECT sdo_pc_pkg.create_contour_geometries( (SELECT pc FROM pcs WHERE pc_id = 1), sampling_resolution => 50, elevations => sdo_ordinate_array(100, 101, 102, 103, 104, 105, 106, 107, 108, 109), region => mdsys.sdo_geometry(2003, null, null, mdsys.sdo_elem_info_array(1, 1003, 3), mdsys.sdo_ordinate_array(-1000, 0, 999, 100))) FROM DUAL; SDO_PC_PKG.CREATE_CONTOUR_GEOMETRIES((SELECTPCFROMPCSWHEREPC_ID=1),SAMPLING_RESO -------------------------------------------------------------------------------- SDO_GEOMETRY_ARRAY(SDO_GEOMETRY(2002, NULL, NULL, SDO_ELEM_INFO_ARRAY(1, 2, 1, 5 , 2, 1), SDO_ORDINATE_ARRAY(-75.5, 24.5, -25.5, 74.5, 25.5, 74.5, 74.5, 25.5, 75 .5, 24.5)), SDO_GEOMETRY(2002, NULL, NULL, SDO_ELEM_INFO_ARRAY(1, 2, 1, 7, 2, 1) , SDO_ORDINATE_ARRAY(-76.5, 24.5, -75.5, 25.5, -26.5, 74.5, 26.5, 74.5, 74.5, 26 .5, 76.5, 24.5)), SDO_GEOMETRY(2002, NULL, NULL, SDO_ELEM_INFO_ARRAY(1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-77.5, 24.5, -75.5, 26.5, -27.5, 74.5, 27.5, 74.5, 74 .5, 27.5, 77.5, 24.5)), SDO_GEOMETRY(2002, NULL, NULL, SDO_ELEM_INFO_ARRAY(1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-78.5, 24.5, -75.5, 27.5, -28.5, 74.5, 28.5, 74 .5, 74.5, 28.5, 78.5, 24.5)), SDO_GEOMETRY(2002, NULL, NULL, SDO_ELEM_INFO_ARRAY (1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-79.5, 24.5, -75.5, 28.5, -29.5, 74.5, 29 .5, 74.5, 74.5, 29.5, 79.5, 24.5)), SDO_GEOMETRY(2002, NULL, NULL, SDO_ELEM_INFO _ARRAY(1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-80.5, 24.5, -75.5, 29.5, -30.5, 74 .5, 30.5, 74.5, 74.5, 30.5, 80.5, 24.5)), SDO_GEOMETRY(2002, NULL, NULL, SDO_ELE M_INFO_ARRAY(1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-81.5, 24.5, -75.5, 30.5, -31 .5, 74.5, 31.5, 74.5, 74.5, 31.5, 81.5, 24.5)), SDO_GEOMETRY(2002, NULL, NULL, S DO_ELEM_INFO_ARRAY(1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-82.5, 24.5, -75.5, 31. 5, -32.5, 74.5, 32.5, 74.5, 74.5, 32.5, 82.5, 24.5)), SDO_GEOMETRY(2002, NULL, N ULL, SDO_ELEM_INFO_ARRAY(1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-83.5, 24.5, -75. 5, 32.5, -33.5, 74.5, 33.5, 74.5, 74.5, 33.5, 83.5, 24.5)), SDO_GEOMETRY(2002, N ULL, NULL, SDO_ELEM_INFO_ARRAY(1, 2, 1, 7, 2, 1), SDO_ORDINATE_ARRAY(-84.5, 24.5 , -75.5, 33.5, -34.5, 74.5, 34.5, 74.5, 74.5, 34.5, 84.5, 24.5))) 1 row selected.
Parent topic: SDO_PC_PKG Package (Point Clouds)