Format

SDO_PC_PKG.CLIP_PC(
     inp           IN SDO_PC, 
     ind_dim_qry   IN SDO_GEOMETRY, 
     other_dim_qry IN SDO_MBR, 
     qry_min_res   IN NUMBER, 
     qry_max_res   IN NUMBER, 
     blkno         IN NUMBER DEFAULT NULL, 
     include_custom_dims IN NUMBER DEFAULT 0 
     ) RETURN SDO_PC_BLK_TYPE;

Description

Performs a clip operation on a point cloud.

Parameters

inp

Point cloud on which to perform the clip operation.

ind_dimqry

For querying the indexed dimensions of the point cloud: window from which to select objects to be returned; typically a polygon for two-dimensional geometries or a frustum for three-dimensional geometries.

other_dimqry

For querying the nonindexed dimensions of the point cloud: window from which to select objects to be returned; typically a polygon for two-dimensional geometries or a frustum for three-dimensional geometries. The nonindexed dimensions are those that are included in the total dimensionality but are not indexed. For an explanation of index dimensionality and total dimensionality, see the explanation of the pc_tot_dimensions parameter of the SDO_PC_PKG.INIT function.

The SDO_MBR type is defined as (LOWER_LEFT SDO_VPOINT_TYPE, UPPER_RIGHT SDO_VPOINT_TYPE) and SDO_V_POINT_TYPE is defined as VARRAY(64) OF NUMBER.

qry_min_res

Minimum resolution value. Objects in qry with resolutions equal to or greater than qry_min_res and less than or equal to qry_max_res are returned by the clip operation.

qry_max_res

Maximum resolution value. Objects in qry with resolutions equal to or greater than qry_min_res and less than or equal to qry_max_res are returned by the clip operation.

blkid

Block ID number of the block to which to restrict the objects returned by the clip operation. If this parameter is null, all objects that satisfy the other parameters are returned.

include_custom_dims

Numeric value 0 or 1, which determines whether the point cloud blocks returned by the function contain only the regular (type NUMBER) dimensions, as included in the PC_TOT_DIMENSIONS count of SDO_PC. If only these regular dimensions should be returned, then include_custom_dims=0 (the default). The stored point cloud blocks in the block table still contain any additional custom dimensions, but this individual CLIP_PC query then does not return them.

include_custom_dims=1 includes both regular and custom dimensions.

See the Usage Notes for more information about custom dimensions.

Usage Notes

This function returns points from a point cloud that are within a specified query window and that satisfy any other requirements specified by the parameters. A common use of this function is to perform queries on point clouds. You can maximize the performance of a point cloud query by minimizing the number of objects that the function needs to consider for the operation.

The SDO_PC and SDO_PC_BLK_TYPE data types are described in Point Cloud-Related Object Types.

This function supports the storage and querying of custom dimensions. Custom dimensions can be of type NUMBER or other types, and they are not included in the PC_TOT_DIMENSIONS count of SDO_PC. If include_custom_dims=1, the custom dimensions can be part of a query result, but they cannot be part of the query restriction, either in the ind_dimqry or other_dimqry parameters, because custom dimensions might not be of numeric type (and thus cannot be represented in the numeric interface of ind_dimqry or other_dimqry).

Custom dimensions cannot be created using the SDO_PC_PKG.CREATE_PC procedure.

Contrast this function with SDO_PC_PKG.CLIP_PC_FLAT, which takes as input point cloud data stored in a flat table (as opposed to an SDO_PC object).

Modeling Solids describes how to use point clouds to model solids.

Examples

The following example performs a clip operation on a point cloud. It is taken from the $ORACLE_HOME/md/demo/PointCloud/examples/plsql/pc.sql example program, which is available if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

. . .
declare
  inp  sdo_pc;
begin
  select pc INTO inp  from base where rownum=1;
  insert into restst
    select * from
      table(sdo_pc_pkg.clip_pc
           (
            inp,  -- Input point cloud object
            sdo_geometry(2003, 8307, null,
              sdo_elem_info_array(1, 1003, 3),
              sdo_ordinate_array(-175.86157, -14.60521, 0,0)), -- Query 
              null, null, null));
end;
/
. . .

Format

SDO_PC_PKG.CLIP_PC_FLAT(
     geometry       IN SDO_GEOMETRY, 
     table_name     IN VARCHAR2, 
     tolerance      IN NUMBER, 
     other_dim_qry  IN SDO_MBR, 
     mask           IN VARCHAR2 DEFAULT NULL 
     ) RETURN REF CURSOR;

Description

Performs a clip operation on a flat-format point cloud, in which the point cloud data is stored in a flat table.

Parameters

geometry

Two-dimensional geometry to serve as the clip window. For example:

geometry =>
  SDO_GEOMETRY(
    2003,
    NULL,
    NULL,
    SDO_ELEM_INFO_ARRAY(1, 1003, 3),
    SDO_ORDINATE_ARRAY(
      0.75, 0.75,
      1.25, 1.25))

table_name

Name of the table or view containing the point cloud data. The first two columns in the table or view must be named X and Y and be of type Oracle NUMBER. Optionally, following X and Y, the table or view can contain a Z column of type NUMBER, and additional nonspatial point cloud attributes. The additional nonspatial point cloud attributes can be any data type, but must be type Oracle NUMBER if they will participate as constraints in the other_dim_qry parameter.

tolerance

Tolerance value for objects in the point cloud (see Tolerance for information about spatial tolerance). If this parameter is null, the default value is 0.0000000000005

other_dim_qry

Minimum bounding rectangle (MBR) to provide a user defined query ranges for any Oracle NUMBER type columns (not including the X and Y columns).

The SDO_MBR type is defined as (LOWER_LEFT SDO_VPOINT_TYPE, UPPER_RIGHT SDO_VPOINT_TYPE) and SDO_V_POINT_TYPE is defined as VARRAY(64) OF NUMBER.

Specify NULL in the SDO_V_POINT_TYPE array for Oracle NUMBER type columns that are not constrained by a query range.

mask

The topological relationship of interest, as applicable to points interacting with polygons. Valid values are 'mask=<value>' where <value> is one or more of the mask values valid for the SDO_RELATE operator (TOUCH, OVERLAPBDYDISJOINT, OVERLAPBDYINTERSECT, EQUAL, INSIDE, COVEREDBY, CONTAINS, COVERS, ANYINTERACT, ON), or FILTER, which performs an approximate check. FILTER will return all the candidates that intersect the polygon, and possibly a few more. Multiple masks are combined with the logical Boolean operator OR (for example, 'mask=inside+touch'); however, FILTER cannot be combined with any other mask.

If this parameter is null or contains an empty string, mask=ANYINTERACT is assumed.

Usage Notes

This function works with flat-format point clouds, in contrast to SDO_PC_PKG.CLIP_PC, which works with input point cloud data stored in an SDO_PC object. The flat format has been added to point cloud support to offer an alternative to SDO_PC, depending on hardware environment and usage patterns. One advantage of the flat format is its dynamic nature, since updates to the point data do not require reblocking.

In environments other than Exadata, it is highly recommended that you create a compound B-tree index on the X, Y columns. In the compound B-tree index, also include any other Oracle NUMBER columns that will constrained with user-defined query ranges described for the other_dim_qry parameter. Any point cloud data update will result in an automatic update of that B-tree index.

Contrast this function with SDO_PC_PKG.CLIP_PC, which takes as input point cloud data stored in an SDO_PC object.

Modeling Solids describes how to use point clouds to model solids. It includes some discussion of the SDO_PC and flat table approaches for storing point cloud data.

Examples

The following example creates a view named INPTAB2 from the first three columns of a table named INPPTAB. It then performs a clip operation on the point cloud date.

CREATE VIEW inptab2 AS (select x x, y y, z z from inptab);
 
DECLARE
  my_cursor sys_refcursor;
  TYPE rec IS RECORD(x NUMBER, y NUMBER, z number);
  TYPE lst IS TABLE OF rec;
  result_list lst;
BEGIN
  my_cursor :=
    SDO_PC_PKG.CLIP_PC_FLAT(
      geometry =>
        MDSYS.SDO_GEOMETRY(
          2003,
          NULL,
          NULL,
          MDSYS.SDO_ELEM_INFO_ARRAY(1, 1003, 3),
          MDSYS.SDO_ORDINATE_ARRAY(
            0.75, 0.75,
            1.25, 1.25)),
      table_name    => 'INPTAB2',
      tolerance     => 0.05,
      other_dim_qry => null,
      mask          => null);
 
  FETCH my_cursor BULK COLLECT INTO result_list;
  FOR I in 1 .. result_list.COUNT LOOP
    dbms_output.put_line(
      '(' || result_list(i).x || ', ' ||
             result_list(i).y || ', ' ||
             result_list(i).z || ')');
  END LOOP;
  CLOSE my_cursor;
END;
/

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 and elevations_max when generating coutours.

For example, if elevations_min is 100, elevations_max is 150, and elevations_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.

Format

SDO_PC_PKG.CREATE_PC(
     inp           IN SDO_PC, 
     inptable      IN VARCHAR2, 
     clstPcdataTbl IN VARCHAR2 DEFAULT NULL);

Description

Creates a point cloud using the points specified in the inptable parameter.

Parameters

inp

SDO_PC object to be used. This object must have been created by the SDO_PC_PKG.INIT function.

inptable

Name of the table or view containing the input point cloud data. This table or view should have the following columns:

• RID (VARCHAR2(24)): Unique ID for each point

• VAL_D1 (NUMBER): Ordinate in dimension 1

• VAL_D2 (NUMBER): Ordinate in dimension 2

• . . .

• VAL_Dn (NUMBER): Ordinate in dimension n, where n is the highest-numbered dimension. n should match the pc_tot_dimensions parameter value in the call to the SDO_PC_PKG.INIT function when the point cloud was initialized.

clstPcdataTbl

Name of the table for storing the resulting point data. If you do not specify a value, this table is not created. For more information about the table, see the Usage Notes.

Usage Notes

The first few dimensions of the point cloud are indexed and can later be searched using the SDO_PC_PKG.CLIP_PC function. The exact number of dimensions to index is determined by the dimensionality of the point cloud extent in the initialized point cloud object, specifically: inp.pc_extent.sdo_gtype/1000

If you specify a view name in the inptable parameter, the query SELECT ROWID FROM <view-name> must not return any errors.

If you specify a table name in the clstPcdataTbl parameter, the table must exist and have the following columns:

• PTN_ID (NUMBER)

• POINT_ID (NUMBER)

• RID (VARCHAR2(24): Unique ID for each point

• VAL_D1 (NUMBER): Ordinate in dimension 1

• VAL_D2 (NUMBER): Ordinate in dimension 2

• . . .

• VAL_Dn (NUMBER): Ordinate in dimension n, where n is the highest-numbered dimension. n should match the pc_tot_dimensions parameter value in the call to the SDO_PC_PKG.INIT function when the point cloud was initialized.

If a value is specified for the clstPcdataTbl parameter, this function populates the table by assigning appropriate values for PTN_ID and POINT_ID and by copying the values from the inptable table or view for other attributes. This table can be created as an index organized table. It can be used in applications for searching using SQL queries on dimensions other than those reflected in the index dimensionality. (For an explanation of index dimensionality and total dimensionality, see the explanation of the pc_tot_dimensions parameter of the SDO_PC_PKG.INIT function.)

The SDO_PC and SDO_PC_BLK_TYPE data types are described in Point Cloud-Related Object Types.

Modeling Solids describes how to use point clouds to model solids.

Examples

The following example creates a point cloud. It is taken from the $ORACLE_HOME/md/demo/PointCloud/examples/plsql/pc.sql example program, which is available if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

. . .
-- Create the blocks for the point cloud.
sdo_pc_pkg.create_pc(
  pc,       -- Initialized PointCloud object
  'INPTAB', -- Name of input table to ingest into the pointcloud
  'RES'     -- Name of output table that stores the points (with ptn_id,pt_id)
  );
. . .

Format

SDO_PC_PKG.DROP_DEPENDENCIES(
     basetable IN VARCHAR2, 
     col       IN VARCHAR2);

Description

Drops the dependencies between a point cloud block table and a specified base table and column.

Parameters

basetable

Name of a base table that was specified (in the basetable parameter of the SDO_PC_PKG.INIT function) when the point cloud was initialized.

col

Name of a column in base table that was specified in the basecol parameter of the SDO_PC_PKG.INIT function.

Usage Notes

This procedure truncates the point cloud block table and removes the association between the block table and the base table and column combination.

After you execute this procedure, you can drop the point cloud block table or associate the table with another base table and column combination. For more information, see the Usage Notes for the SDO_PC_PKG.INIT function.

Examples

The following example drops the dependencies between a point cloud block table and a base table and column named BASE and PC, respectively.

. . .
declare
begin
  mdsys.sdo_pc_pkg.drop_dependencies('BASE', 'PC');
end;
/

Format

SDO_PC_PKG.GET_PT_IDS(
     pts         IN BLOB, 
     num_pts     IN NUMBER, 
     pc_tot_dim  IN NUMBER, 
     blk_domain  IN SDO_ORGSCL_TYPE DEFAULT NULL, 
     ) RETURN SDO_NUMBER_ARRAY;

Description

Returns the block ID and point ID values of the points in a block in a point cloud.

Parameters

pts

Binary large object (BLOB) containing the point cloud block.

num_pts

Number of points in the point cloud block. For a point cloud block, the number of points is stored in the NUM_POINTS column of the point cloud block table, which is described in Table 2-7 in SDO_PC Object Type.

pc_tot_dim

Number of dimensions for the points in the point cloud block.

blk_domain

(Not currently used.)

Usage Notes

This function returns an SDO_NUMBER_ARRAY object. The array contains multiple pairs of numbers, with each pair identifying the block ID and point ID of a point. For any specific call to this function, the block ID values associated with all points in the returned array will be the same. The SDO_NUMBER_ARRAY type is defined as VARRAY(1048576) OF NUMBER.

Modeling Solids describes how to use point clouds to model solids.

Examples

The following example returns the block ID and point ID values of points in a point cloud block. It is taken from the $ORACLE_HOME/md/demo/PointCloud/examples/plsql/pc.sql example program, which is available if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

SELECT SDO_PC_PKG.GET_PT_IDS(
    a.points,   -- LOB containing the points
    a.num_points, -- # of points in the LOB
    3 -- Total dimensionality of the points in the LOB
) FROM restst a WHERE num_points >0;

Format

SDO_PC_PKG.INIT(
     basetable          IN VARCHAR2, 
     basecol            IN VARCHAR2, 
     blktable           IN VARCHAR2, 
     ptn_params         IN VARCHAR2, 
     pc_extent          IN SDO_GEOMETRY, 
     pc_tol             IN NUMBER DEFAULT 0.0000000000005, 
     pc_tot_dimensions  IN NUMBER DEFAULT 2, 
     pc_domain          IN SDO_ORGSCL_TYPE DEFAULT NULL, 
     pc_val_attr_tables IN SDO_STRING_ARRAY DEFAULT NULL, 
     pc_other_attrs     IN XMLTYPE DEFAULT NULL, 
     ) RETURN SDO_PC;

Description

Initializes a point cloud by creating an SDO_PC object.

Parameters

basetable

Name of the base table containing a column of type SDO_PC.

basecol

Name of the column of type SDO_PC in the base table.

blktable

Name of the point cloud block table, which is used for storing the blocks of point cloud. This table must exist, and must have been created by a statement in the following form: CREATE TABLE <table-name> AS select * from mdsys.sdo_pc_blk_table;

Each point cloud block table can only be associated with only one basetable and basecol combination.

ptn_params

Parameters for partitioning the point cloud, specified as a quoted string with keywords delimited by commas. For example: 'blk_capacity=1000,work_tablespace=my_work_ts'. If this parameter is null, the point cloud is not partitioned. The following keywords are permitted:

• blk_capacity=n, where n is the maximum number of rows in each partition. The default value is 5000. If specified, must be a number greater than or equal to 50.

• work_tablespace=x, where x is the name of the tablespace in which to create temporary tables during the partitioning operations.

pc_extent

SDO_GEOMETRY object representing the spatial extent of the point cloud (the minimum bounding object enclosing all objects in the point cloud). This parameter must not be null.

For geodetic data, this geometry must have two dimensions; otherwise, it can have up to four dimensions. The dimensionality of this geometry is used as the minimum value permitted for the pc_tot_dimensions parameter, as explained in the description of that parameter.

pc_tol

Tolerance value for objects in the point cloud. (For information about spatial tolerance, see Section 1.5.5.) If this parameter is null, the default value is 0.0000000000005.

pc_tot_dimensions

A number specifying the total dimensionality of the point cloud object. For each point in the point cloud blocks, pc_tot_dimensions ordinates (values) are stored.

The total dimensionality must be greater than or equal to the index dimensionality, which is the number of dimensions in the pc_extent geometry. Specifying total dimensionality greater than index dimensionality enables necessary nonspatial attributes to be retrieved in the same fetch operation with spatial data. The maximum total dimensionality value is 8. The default value for this parameter is 2.

pc_domain

(Not currently used.)

pc_val_attr_tables

SDO_STRING_ARRAY object specifying the names of any value attribute tables for the point cloud. If this parameter is null, the point cloud has no associated value attribute tables. Type SDO_STRING_ARRAY is defined as VARRAY(1048576) OF VARCHAR2(32).

pc_other_attrs

XMLTYPE object specifying any other attributes of the point cloud. If this parameter is null, the point cloud has no other attributes.

This parameter can include metadata on point cloud pyramiding, as explained in the Usage Notes.

Usage Notes

After you use this function to initialize an SDO_PC object, you can create a point cloud by specifying this object as input to the SDO_PC_PKG.CREATE_PC procedure.

The SDO_PC data type is described in TIN-Related Object Types.

Modeling Solids describes how to use point clouds to model solids.

After you use this function, the blktable table is kept in synchronization with the base table. For example, if a row is deleted from the basetable, the corresponding blocks of the point cloud object in that row are also deleted from the block table; and if the base table base table is truncated, the block table is truncated also.

The block table can be dropped only after either of the following occurs: the base table is dropped, or the SDO_PC_PKG.DROP_DEPENDENCIES procedure is executed.

The pc_other_attrs parameter can be used to specify metadata for point cloud pyramiding, for example:

xmltype(
 '<opc:sdoPcObjectMetadata
    xmlns:opc="http://xmlns.oracle.com/spatial/vis3d/2011/sdovis3d.xsd"
    xmlns:las="http://liblas.org/schemas/LAS/1.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <opc:sdoPcPyramid preserveLevel1="true"/>
  </opc:sdoPcObjectMetadata>')

The XML Schema Definition (XSD) for the pc_other_attrs parameter can be viewed by entering the following statements:

SET LONG 40000
SELECT xmlschema FROM sdo_xml_schemas WHERE description = 'EPSG  sdo3d.xsd';

Point cloud pyramiding creates multiple pyramid levels from level 1 (leaves) to level n (root). Generally, points already stored at level i are not repeated, at any of the more detailed levels. Any point is physically stored, exactly once. The leaf level 1 can be exempted from this rule by specifying preserveLevel1="true" (as in the preceding example), so that applications that are not pyramiding-compliant do not need to adapt. However, this preserveLevel1="true" option (of exempting and thus preserving level 1) doubles the space requirement, because each point is then stored twice: once at root level 1, and once in the rest of the pyramid.

Examples

The following example initializes a point cloud by creating an SDO_PC object, and it displays the ID of the object. It is taken from the $ORACLE_HOME/md/demo/PointCloud/examples/plsql/pc.sql example program, which is available if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

. . .
declare
  pc sdo_pc;
begin
  -- Initialize the point cloud object. 
  pc := sdo_pc_pkg.init(
          'BASE', -- Table that has the SDO_POINT_CLOUD column defined
          'PC',   -- Column name of the SDO_POINT_CLOUD object 
          'BLKTAB', -- Table to store blocks of the point cloud
          'blk_capacity=1000', -- max # of points per block 
          mdsys.sdo_geometry(2003, 8307, null,
              mdsys.sdo_elem_info_array(1,1003,3),
              mdsys.sdo_ordinate_array(-180, -90, 180, 90)),  -- Extent 
              0.5, -- Tolerance for point cloud
              3, -- Total number of dimensions
              null);
. . .

Format

SDO_PC_PKG.TO_GEOMETRY(
     pts        IN BLOB, 
     num_pts    IN NUMBER, 
     pc_tot_dim IN NUMBER, 
     srid       IN NUMBER DEFAULT NULL, 
     blk_domain IN SDO_ORGSCL_TYPE DEFAULT NULL 
     ) RETURN SDO_GEOMETRY;

Description

Returns a geometry object representing all or part of a point cloud.

Parameters

pts

BLOB containing the points.

num_pts

Maximum number of points to be included in the resulting geometry.

pc_tot_dim

Number of spatial dimensions defined for the data.

srid

Spatial reference (coordinate system) ID associated with the data. If this parameter is null, no SRID value is associated with the data.

blk_domain

(Not currently used.)

Usage Notes

This function returns a single multipoint SDO_GEOMETRY object that represents all point geometries in the pts parameter. For example, the points could reflect the result of a clip operation or the contents of an entire block.

Modeling Solids describes how to use point clouds to model solids.

Examples

The following example returns a multipoint collection geometry object representing a point cloud. It is taken from the $ORACLE_HOME/md/demo/PointCloud/examples/plsql/pc.sql example program, which is available if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

. . .
-- Return points in blk_id of the point cloud as a multipoint collection.
select sdo_pc_pkg.to_geometry(
                    a.points,   -- point LOB
                    a.num_points, -- # of points in the LOB
                    3,  -- total dimensionality
                    8307 -- SRID
                    ) from blktab a where blk_id=0;
. . .