Calculates the length of a feature from its start until the closest spot to a point, and adds it as a new attribute. The point coordinates are taken from attributes in the original feature.
The length is calculated along the feature up until the spot on the feature that is closest to the given point.
To calculate the length of the entire feature, use the LengthCalculator.
To calculate the distance from the start of the line to each vertex, use the MeasureGenerator.
Length Dimension
By default, the 2-dimensional length of the line is calculated, and any Z values, if present, are ignored. To have a 3D length calculated, the length dimension parameter should be set to 3, and then the elevations will be included in the length computation.
X Value Attribute
The feature attribute from which to derive the x-value point coordinate.
Y Value Attribute
The feature attribute from which to derive the y-value point coordinate.
Z Value Attribute
The feature attribute from which to derive the z-value point coordinate.
Length Attribute
Name of the attribute to hold the length value that is calculated.
Associated FME function or factory: @Length
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.
Search for samples and information about this transformer on the FME Knowledge Center.