PointCloudComponentTypeCoercer

Alters the data type of point cloud components, and converts component values if required.

Typical Uses

Changing component data type to meet processing or format requirements.

How does it work?

The PointCloudComponentTypeCoercer receives point cloud features, alters the data type of selected components, and then outputs the modified point cloud feature.

Options are available to control the manner in which values are converted, including methods for scaling values to fit a new data type and choices for rounding when converting from floating-point values to integers.

Components can be converted to any of these data types:

Real64
Real32
UInt64
UInt32
UInt16
UInt8
Int64
Int32
Int16
Int8
String

Examples

Example: Changing data type and scaling color values

In this example, we will apply color to a point cloud using an orthophoto raster. The raster is RGB48 - that is, each of its color bands are 16 bits.

Note that the source point cloud feature does not have color components (colors shown in the FME Data Inspector are simply a representation of elevation - z coordinates).

We want to produce a point cloud with 8-bit color components, and so need two steps.

First, both the point cloud feature (LAS) and the raster feature (GEOTIFF) are routed into a PointCloudOnRasterComponentSetter, where colors will be extracted from the orthophoto and applied to the point cloud as components.

Next, the resulting point cloud feature (with 16-bit color components) is sent on to a PointCloudComponentTypeCoercer, where the data type will be changed and the color values scaled accordingly.

Step 1 - Applying Colors

In the parameters dialog of the PointCloudOnRasterComponentSetter, Components to Set is set to Color.

Note that the point cloud feature produced in this first step now has color components, and they are data type UInt16 (unsigned integer, 16-bit).

When examining a single point in the point cloud, we can see that the color values fall within the range of 0 to 65535 (the possible values for a 16-bit unsigned integer).

Step 2 - Altering Data Type and Scaling Values

In the parameters dialog of the PointCloudComponentTypeCoercer, all three color components are set to Type UInt8, and the Conversion Type is set to Scale by data type. This will scale the values while preserving their proportions in regard to the original and new types’ ranges.

The output point cloud feature now has 8-bit color components.

Individual points’ color values have been proportionately scaled, and now fall within the range of 1 to 255 - the possible values for an 8-bit unsigned integer.

Usage Notes

Choosing a Point Cloud Transformer

FME has a selection of transformers for working specifically with point cloud data.

For information on point cloud geometry and properties, see Point Clouds (IFMEPointCloud).

Point Cloud Transformers

PointCloudCombiner	Combines features into a single point cloud. Point cloud and non-point cloud geometries are supported.
PointCloudComponentAdder	Adds new components with constant values to a point cloud.
PointCloudComponentCopier	Copies selected component values onto either a new or existing component
PointCloudComponentKeeper	Keeps only specified point cloud components, discarding all others.
PointCloudComponentRemover	Removes specified components from a point cloud.
PointCloudComponentRenamer	Renames an existing component.
PointCloudComponentTypeCoercer	Alters the data type of point cloud components, and converts component values if required.
PointCloudConsumer	Reads point cloud features for testing purposes, including any accumulated point cloud operations. No additional operations are performed, and nothing is done with the features.
PointCloudCreator	Creates a point cloud of specified size and density, with default component values.
PointCloudExpressionEvaluator	Evaluates expressions on each point in a point cloud feature, including algebraic operations and conditional statements, and sets individual point cloud component values.
PointCloudExtractor	Serializes the geometry of a point cloud feature into a Blob attribute, encoding the contents according to a choice of common binary point cloud formats.
PointCloudFilter	Separates point clouds into multiple features, based on evaluating expressions including component values, and creates a separate output port for each expression defined.
PointCloudMerger	Merges point clouds by joining points where selected component values match (join key), including x, y, z, and other components. Component values are transferred between point clouds and output is filtered based on matching success and duplication.
PointCloudOnRasterComponentSetter	Sets point cloud component values by overlaying a point cloud on a raster. The component values for each point are interpolated from band values at the point location.
PointCloudPropertyExtractor	Extracts the geometry properties of a point cloud feature and exposes them as attributes, optionally checking for their existence, retrieving component properties, and finding minimum and maximum values. Extents may also be recalculated and updated.
PointCloudReplacer	Decodes a binary attribute containing encoded point clouds stored as Blobs, replacing the feature’s geometry with the decoded point cloud.
PointCloudSimplifier	Reduces the number of points in a point cloud by selectively keeping points based on the shape of the point cloud. The simplified and removed points are output as two discrete point clouds.
PointCloudSorter	Sorts the points within a point cloud by one or more component values.
PointCloudSplitter	Separates point clouds into multiple features based on component values, color, or first/last return.
PointCloudStatisticsCalculator	Calculates statistics on point cloud components and adds the results as attributes.
PointCloudSurfaceBuilder	Takes an input point cloud and reconstructs it into an output mesh.
PointCloudThinner	Reduces the number of points in (thins) a point cloud by keeping points at a fixed interval, a maximum number of points, or a set quantity of first or last points. Remaining points are discarded.
PointCloudToPointCoercer	Converts point clouds to point or multipoint geometries, optionally retaining attribute and component values.
PointCloudTransformationApplier	Applies a point cloud’s scale, offset, or transformation matrix to it, recalculating component values and removing the transformation values.

Configuration

Input Ports

Output Ports

Parameters

Components to Coerce

Each line in this table specifies a component to be altered, and parameters for doing so.

Multiple components may be modified.

Component

Select or enter the name of the component to be modified.

Type

Select the desired data type of the component.

Conversion Type

Select a method for conversion.

Note Scale/Offset: Note that all conversion types except Scale by data values, preserve values are applied to the raw data values, before any transformation is applied. To convert a value in its end form (as it appears with scale and/or offset applied), use a PointCloudTransformationApplier to apply the scale/offset transformation prior to changing the component data type.

Cast*	Converts values to the chosen type, without validation.
Bounded cast*	Converts values to the chosen type, and validates that the source values fit into the destination type, effectively preventing underflow and overflow. If a source value does not fit, the corresponding destination value will either be set to its type's minimum or maximum value as appropriate.
Scale by data type	Scales the source values while preserving all proportions in regard to the source and destination types' range. This is often used when converting color components, for example, from UInt8 to UInt16.
Scale by data values	Finds the minimum and maximum values of the source values and uses them to scale the values to the full range of the destination type.
Scale by data values, preserve values	Similar to Scale by data values, but also sets a scale and offset on the destination component so that the original values are preserved. This may be useful when you have floating-point values but need to convert them to an integer type, while still preserving the original values. For example, this could be used when reading Real64 coordinates (such as a POINTCLOUDXYZ reader) and writing to a format that only supports integer coordinates (such as the LAS writer).

* Note: Cast and Bounded Cast use C-style casts.

Rounding Type

Specifies the action to perform when converting from a floating-point value to an integer.

Round	Rounds to floating-point value to the nearest integer.
Ceiling	Gets the next integer which is greater than or equal to the floating-point value.
Floor	Gets the next integer which is less than or equal to the floating-point value.

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.

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.

How to Set Parameter Values

Using the Text Editor

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

Text Editor

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

Arithmetic Editor

Conditional Values

Set values depending on one or more test conditions that either pass or fail.

Parameter Condition Definition Dialog

Content

Expressions and strings can include a number of functions, characters, parameters, and more.

When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.

Content Types

String Functions	These functions manipulate and format strings.
Special Characters	A set of control characters is available in the Text Editor.
Math Functions	Math functions are available in both editors.
Date/Time Functions	Date and time functions are available in the Text Editor.
Math Operators	These operators are available in the Arithmetic Editor.
FME Feature Functions	These return primarily feature-specific values.
FME Parameters	FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters	Create your own editable parameters.

Dialog Options - Tables

Transformers with table-style parameters have additional tools for populating and manipulating values.

Table Tools

Row Reordering

Enabled once you have clicked on a row item. Choices include:

Add a row
Remove a row
Move current row up one
Move current row down one
Move current row to top
Move current row to bottom

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:

Cut a row - delete and copy to clipboard
Copy a row to the clipboard
Paste a row from the clipboard

Cut, copy, and paste may be used within a transformer, or between transformers.

Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output.

Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers.

Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers.

Note: Not all tools are available in all transformers.

Reference

Processing Behavior	Feature-Based
Feature Holding	No
Dependencies	None
Aliases	PointCloudColourScaler, PointCloudColorScaler
History

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Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.

Keywords: PointCloudColorScaler