PointCloudCombiner
PointCloudCombiner is often used to accumulate multiple point clouds into a single point cloud feature, but can also convert other geometries into point clouds and merge them.
Point and linear features will be converted point for point. Polygonal, donut, surface and solid features will be converted into a grid of points lying inside the area on the 3D plane represented by the area’s calculated normal. Any existing component values stored as measures or attributes can be preserved as components.
Rasters will be converted to point clouds as follows:
- The x and y components will be created from the columns and rows.
- The first selected numeric band will become the z component.
- The first selected bands with red/green/blue/gray interpretations will become the color_red/color_green/color_blue components.
- Additional selected bands will also be preserved. If the band has a name, the component name will be the band name. If the band has no name, the component name will be bandN, where N is the band index.
Input Ports
This transformer accepts all geometries. Area-based geometries will be converted to point clouds according to the spacing parameter.
Output Ports
A single point cloud feature.
Parameters
Transformer
Use this parameter to organize point clouds into groups. Each group of point clouds will have its own output point cloud.
Process At End (Blocking): This is the default behavior. Processing will only occur in this transformer once all input is present.
Process When Group Changes (Advanced): This transformer will process input groups in order. Changes of the value of the Group By parameter on the input stream will trigger processing on the currently accumulating group. This may improve overall speed (particularly with multiple, equally-sized groups), but could cause undesired behavior if input groups are not truly ordered.
There are two typical reasons for using Process When Group Changes (Advanced) . The first is incoming data that is intended to be processed in groups (and is already so ordered). In this case, the structure dictates Group By usage - not performance considerations.
The second possible reason is potential performance gains.
Performance gains are most likely when the data is already sorted (or read using a SQL ORDER BY statement) since less work is required of FME. If the data needs ordering, it can be sorted in the workspace (though the added processing overhead may negate any gains).
Sorting becomes more difficult according to the number of data streams. Multiple streams of data could be almost impossible to sort into the correct order, since all features matching a Group By value need to arrive before any features (of any feature type or dataset) belonging to the next group. In this case, using Group By with Process At End (Blocking) may be the equivalent and simpler approach.
Note: Multiple feature types and features from multiple datasets will not generally naturally occur in the correct order.
As with many scenarios, testing different approaches in your workspace with your data is the only definitive way to identify performance gains.
Attributes
If this parameter is set to Yes, the attributes from the original features will be merged onto the output point cloud features.
If you specify a Count Attribute parameter (text string), an attribute with this name will be added to each output feature.
The attribute contains the number of features that were combined to create the point cloud feature.
Raster Parameters
This parameter specifies whether points should be created for nodata cells in rasters. When set to Yes, a point will be created for every cell in a raster, regardless of whether it is nodata. When set to No, points will not be created for nodata cells. A cell is considered to be nodata when, for each selected band, the value for that cell is equal to that band's nodata value. If any cell value is not equal to that band's nodata value, the cell will be considered data.
Vector Feature Interpolation
This parameter controls the spacing between points in ground coordinates that will be used to generate the representative point grid used for surfaces, solids, polygons, and donuts. You can either enter a number or extract the value from a selected attribute.
Measures to Preserve as Components
Specifies the measures on input vector geometries that should be preserved as components in the output point cloud. The type of the output component must also be specified.
Attributes to Preserve as Components
Specifies the attributes on input features that should be preserved as components in the output point cloud. The type of the output component must also be specified. Note that if the same component is specified as both a measure and attribute to preserve, the measure value will be preferred.
Editing Transformer Parameters
Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.
Transformer Categories
FME Licensing Level
FME Professional edition and above
Search FME Community
Search for samples and information about this transformer on the FME Community.
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