Chops the input features into a series of tiles.
Features that span multiple tiles will be clipped into multiple features. Features that lie on the boundary between tiles will be output once in each tile. If this is not the desired behavior a DuplicateFilter transformer can be used.
This transformer works with raster, vector and point cloud data.
Note: If you are inputting raster data, you may want to use the RasterTiler instead. The following table compares the Tiler and the RasterTiler:
|Type of data accepted||All types||Raster only|
|Tile size units||Ground coordinates||Pixel coordinates|
|Tile row numbering (0, 1,...)||Selectable||Top to bottom|
|Supports forcing equal-size tiles||No||Yes|
|Supports raster index attribute||No||Yes|
|Supports number of horizontal/vertical tiles attribute||No||Yes|
If Group By attributes are selected, features with the same values in the Group By attributes are placed into the same set, and clipping occurs in each set independent of other sets.
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.
Tile Size: This option enables the Tile Width and Height parameters, which allow you to specify the width and height of each tile in ground units.
Number of Tiles: This option enables the Number of Horizontal and Vertical Tiles parameters, which allow you to specify the number of tiles that will be produced.
These parameters are required when the Tiling Type is Tile Size, and allow you to specify the size of each tile in ground units (for example, 100m x 100m).
Note: If the source is a raster, does not have a coordinate system and is not georeferenced, then the raster extents and spacing are adjusted to default values. The horizontal and vertical spacing are set to one column and one row, respectively, and the origin is set to (0,0).
Note: IMPORTANT: If attributes are used for the Tile Width or Tile Height parameters, the value will be taken from the first feature to enter the transformer. An error will occur if this feature does not have these attributes.
These optional parameters specify a "seed point" from which tiles will be generated. Note that it is permissible to specify a value for only one of these parameters—not necessarily both.
Number of Tiles
These parameters are required when the Tiling Type is Number of Tiles, and allow you to specify how to tile the input data (for example, 5 horizontal tiles and 5 vertical tiles).
The minimum distance between geometries in 2D before they are considered equal, in ground units. If the tolerance is None, the geometries must be exactly identical to be considered equal. If the tolerance is Automatic, a tolerance will be automatically computed based on the location of the input geometries. Additionally, a custom tolerance may be used.
Chooses a starting corner for the purposes of numbering rows and columns. Also, when Tiling Type is Tile Size, the last row and/or the last column may extend beyond the bounds of the input features; here the “last” row or column is the one opposite the Starting Corner.
This parameter allows elements along the border of more than one tile to be duplicated and added to each tile that they touch.
This parameter specifies how to deal with geometries that have a measure, but are missing at least one value, or that have z values, but are missing at least one value. None (Drop Values) will cause the incomplete measure or z values to be removed. Compute will look at the values on either side of the missing value, and then provide an estimate. Additionally, the missing values can be filled in by a custom default value.
In any mode, if no value is given for the z values, the output will be 2D. If no value is given for a measure, the measure will be removed.
When using the Compute mode to compute missing measure values, measures can be considered Continuous, and linearly interpolated from their neighbors, or they can be Discrete, and taken exactly from the nearest neighbor.
If set to Yes, then contiguous lines that constitute the boundary of the output features will be left as separate segments in a path. The default is No, which means that such lines will be joined into longer lines in the output unless they have different properties (for example, traits, measures, and geometry name).
Each feature output from the Tiler will have a row and a column attribute added, specifying the zero-based row and column that the feature fell into. Row 0, Column 0 corresponds to the tile in the bottom-left corner.
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.
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.
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.
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.
Set values depending on one or more test conditions that either pass or fail.
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.
|These functions manipulate and format strings.|
|A set of control characters is available in the Text Editor.|
|Math functions are available in both editors.|
|Date/Time Functions||Date and time functions are available in the Text Editor.|
|These operators are available in the Arithmetic Editor.|
|These return primarily feature-specific values.|
|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.
Enabled once you have clicked on a row item. Choices include:
Cut, Copy, and Paste
Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers.
|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 populates the table with a set of new attributes read from a dataset. Specific application varies between transformers.|
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.
The FME Community is the place for demos, how-tos, articles, FAQs, and more. Get answers to your questions, learn from other users, and suggest, vote, and comment on new features.
Search for samples and information about this transformer on the FME Community.
Keywords: raster grid clip subset tile extent bound limit Tessellate Tessellation pointcloud