Get Subset from Virtual Point Cloud
- Author: V. Wichmann, LASERDATA GmbH (c) 2014
- Menu: File | Virtual | Point Cloud
Description
The tool allows one to retrieve a point cloud from a virtual point cloud dataset by applying the provided area-of-interest (AOI). The extent of the AOI can be provided either as polygon shapefile, grid or by coordinates. Optionally, an overlap can be added to the AOI and a spcvf tile info file can be outputted. The latter can be used to remove the overlap later.
In case an overlap is used and the AOI is provided as polygon shapfile, only the bounding boxes of the polygons are used.
With polygon shapefiles additional functionality is available:
* in case one or more polygons are selected, only the selected polygons are used.
* in case the shapefile contains several polygons and the 'One Point Cloud per Polygon' parameter is checked, a point cloud dataset is outputted for each polygon. In case the 'Tilename' attribute is provided, the output files are named by this attribute. Otherwise the output file names are build from the lower left coordinate of each tile.
The derived datasets can be outputted either as point cloud list or written to an output directory. For the latter, you must provide a valid file path with the 'Optional Output Filepath' parameter.
Optionally, the query can be constrained by providing an attribute field and a value range that must be met.
A virtual point cloud dataset is a simple XML format with the file extension .spcvf, which can be created with the 'Create Virtual Point Cloud Dataset' tool.
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Shape | shapes, input, optional | AOI_SHP | Shapefile describing the AOI. | - |
| Grid | grid, input, optional | AOI_GRID | Grid describing the AOI. | - |
| Output | Point Cloud | point cloud list, output, optional | PC_OUT | The output point cloud(s) | - |
| Options | Filename | file path | FILENAME | The full path and name of the .spcvf file | - |
| Optional Output Filepath | file path | FILEPATH | The full path to which the output(s) should be written. Leave empty to output the datasets as point cloud list. | - |
| Copy existing Attributes | boolean | COPY_ATTR | Copy attributes from input to output point cloud. | Default: 1 |
| Copy Attributes | text | ATTRIBUTE_LIST | Field numbers (starting from 1) of the attributes to copy, separated by semicolon; fields one to three (x;y;z) are mandatory. | Default: 1;2;3 |
| Constrain Query | boolean | CONSTRAIN_QUERY | Check this parameter to constrain the query by an attribute range. | Default: 0 |
| Attribute Field | integer number | ATTR_FIELD | The attribute field to use as constraint. Field numbers start with 1. | Minimum: 1
Default: 1 |
| Value Range | value range | VALUE_RANGE | Minimum and maximum of attribute range []. | - |
| Tilename | table field | FIELD_TILENAME | Attribute used for naming the output file(s) | - |
| Grid system | grid system | AOI_GRID_GRIDSYSTEM | - | - |
| X-Extent | value range | AOI_XRANGE | Minimum and maximum x-coordinate of AOI. | - |
| Y-Extent | value range | AOI_YRANGE | Minimum and maximum y-coordinate of AOI. | - |
| Add Overlap | boolean | AOI_ADD_OVERLAP | Add overlap to AOI | Default: 0 |
| Overlap | floating point number | OVERLAP | Overlap [map units] | Minimum: 0.000000
Default: 50.000000 |
| Optional Tile Info Filename | file path | FILENAME_TILE_INFO | The full path and name of an optional spcvf tile info file. Such a file contains information about the bounding boxes without overlap and can be used to remove the overlap from the tiles later. Leave empty to not output such a file. | - |
| One Point Cloud per Polygon | boolean | ONE_PC_PER_POLYGON | Write one point cloud dataset for each polygon | Default: 0 |
Command Line
Usage: saga_cmd io_virtual 1 [-FILENAME ] [-PC_OUT ] [-FILEPATH ] [-COPY_ATTR ] [-ATTRIBUTE_LIST ] [-CONSTRAIN_QUERY ] [-ATTR_FIELD ] [-VALUE_RANGE_MIN ] [-VALUE_RANGE_MAX ] [-AOI_SHP ] [-FIELD_TILENAME ] [-AOI_GRID ] [-AOI_XRANGE_MIN ] [-AOI_XRANGE_MAX ] [-AOI_YRANGE_MIN ] [-AOI_YRANGE_MAX ] [-AOI_ADD_OVERLAP ] [-OVERLAP ] [-FILENAME_TILE_INFO ] [-ONE_PC_PER_POLYGON ]
-FILENAME: Filename
file path
-PC_OUT: Point Cloud
point cloud list, output, optional
-FILEPATH: Optional Output Filepath
file path
-COPY_ATTR: Copy existing Attributes
boolean
Default: 1
-ATTRIBUTE_LIST: Copy Attributes
text
Default: 1;2;3
-CONSTRAIN_QUERY: Constrain Query
boolean
Default: 0
-ATTR_FIELD: Attribute Field
integer number
Minimum: 1
Default: 1
-VALUE_RANGE_MIN: Value Range
value range
-VALUE_RANGE_MAX: Value Range
value range
-AOI_SHP: Shape
shapes, input, optional
-FIELD_TILENAME: Tilename
table field
-AOI_GRID: Grid
grid, input, optional
-AOI_XRANGE_MIN: X-Extent
value range
-AOI_XRANGE_MAX: X-Extent
value range
-AOI_YRANGE_MIN: Y-Extent
value range
-AOI_YRANGE_MAX: Y-Extent
value range
-AOI_ADD_OVERLAP: Add Overlap
boolean
Default: 0
-OVERLAP: Overlap
floating point number
Minimum: 0.000000
Default: 50.000000
-FILENAME_TILE_INFO: Optional Tile Info Filename
file path
-ONE_PC_PER_POLYGON: One Point Cloud per Polygon
boolean
Default: 0