Licensing options for this format begin with FME Professional Edition.
Note: Google is ending support for Google Maps Engine on January 29, 2016. All Google Maps Engine functionality may stop working after this date.
The Google Maps Engine Raster plug-in enables FME to read and write raster features on Google Maps Engine.
Tutorials
Video tutorials: how to automatically synchronize any data with Google Maps Engine.
Overview
Google Maps Engine is a platform for publishing custom maps through Google’s cloud infrastructure. Data uploaded to Google Maps Engine can then be published and visualized in Google Maps.
Google Maps Engine contains multiple resource types, including Assets, Layers, Maps, Projects, Rasters, Raster Collections (mosaics) and Vector Tables. This format allows you to read and write raster assets and raster collections. To read and write vector tables, use the Google Maps Engine Tables Reader/Writer.
In FME, a Google Maps Engine raster asset or raster collection asset is a feature type; a Google Maps Engine raster file is an FME feature.
Note: The Google Maps Engine Raster Reader/Writer uses the Google Maps Engine API. This API is only accessible to users with an active Maps Engine account. Google Maps Engine Lite accounts cannot be accessed using this reader/writer.
Google Maps Engine may only be accessed over HTTPS. If you are connecting via a proxy server, ensure that it supports HTTPS.
Duplicate raster names
Google Maps Engine allows for duplicate raster or raster collection asset names. The Google Maps Engine Raster Writer will try to match feature types with a unique asset name.
To obtain the Asset ID for a raster: Open the details page for the table in the Google Maps Engine web interface, and click the Asset links button.
API Limits
The Google Maps Engine API is subject to usage limits. It allows up to 3 requests per user per second, but the Google Maps Engine Tables Writer will not throttle its requests.
Refer to the Google Maps Engine API documentation for information on these limits.
Authentication
Google Maps Engine uses OAuth 2.0 authentication. The Google Maps Engine Raster reader/writer accepts a Refresh Token directive instead of a username and password.
To obtain a refresh token: Click the browse button next to the Refresh Token field in the reader or writer parameters dialog.
It is recommended that you save the defaults (from the Defaults button on the dialog) once the refresh token is retrieved so you will not have to re-authenticate in the future. You will need to re-add the reader or writer to older workspaces so they will run properly.
Reader Overview
The Google Maps Engine Raster Reader uses the Google Maps Engine API to read raster and raster collection assets as raster features. When reading a raster asset from GME, the feature type will be set from the raster asset name. When reading a raster collection from GME, the feature type will be set from the raster collection asset name.
If the chosen Google Maps Engine project contains multiple raster or raster collection assets with the same name the id of such assets will be appended in the feature type name to remove any ambiguity.
Writer Overview
The Google Maps Engine Raster Writer uses the Google Maps Engine API to write raster features as raster assets on GME. When writing a new raster asset to GME, the feature type will be treated as the raster asset name. Additionally, the feature type can be used to specify a specific asset ID to replace an existing raster. In either case the raster filename will be used as the uploaded raster filename. This writer also allows for the creation of raster collections, when a raster collection name is specified either by format attribute or by a parameter on the feature type properties, a raster collection will be created and associated features will be added as raster asset members of the collection.
If no raster assets on GME match the feature type name, then the reader will create a new raster asset. If a single raster asset matches the feature type name, then the writer will update the raster file of that asset with the feature. If multiple raster assets share the same name, then the writer will produce an error. To resolve this ambiguity, the feature type can be renamed to the desired asset ID in order to update a specific raster.
FME Raster Features
FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data. See About FME Rasters.