Working with Basemaps and Layersets
Do you have a shapefile or Google Earth file that you’d like to bring into MapItFast? AgTerra offers three options for importing and viewing spatial data on the MapItFast web and mobile application. This post is designed help you determine which option is right for your data.
MapItFast Objects are the most interactive type of map feature. Objects can be queried, selected, and edited. Users can tap on a point, line, polygon or photo to view a pop-up window with the object’s attributes. Attributes can be modified by changing the object name, description, or by adding a Strider form. If a user has “Edit’ capabilities within a project, he or she may move a point object or adjust vertices on lines and polygon objects. Because MapItFast objects are vector based and can potentially contain a large number of attributes, MapItFast limits users to 1,000 objects per import and 5,000 total objects in a single project. Exceeding this number could result in an unresponsive web browser, mobile application, or both. If you’re working with large shapefiles, it is a good idea to split the data into separate projects or consider creating a layerset or custom basemap with the data instead.
Layersets are raster (image) based map overlays that lay on top of any basemap. When a layerset is created, image tiles are processed at each zoom level. Once processed, a layerset can be used online or offline. Layersets are useful when you want to view points, lines and/or polygons as an additional reference layer on a map. Because they are raster images, layerset objects are not interactive like map objects. This option is good for data that does not need to be edited: milepost location, parcel boundaries, wildlife migration routes, etc.
Basemaps are individual images of a map (called tiles) generated at a particular resolution and stitched together to create a seamless map. Map tiles make it possible for mobile devices to rapidly access and deliver map images. Basemaps in MapItFast can be viewed online (i.e. streamed via a data connection) or offline (i.e. accessed from the device’s SD card). For users who want to go beyond the default basemap options in MapItFast, custom basemaps are a powerful and customizable option. Custom basemaps are excellent for viewing maps with a lot of cartographic content or aerial imagery. They are created as “tile sets” at multiple zoom levels so that the map image is rapidly rendered for the user with optimum clarity. MapItFast accepts two file formats for custom basemaps: MIFzip and MBTiles.
Advantages and Disadvantages
What type of spatial map data you use with MapItFast is driven by your particular needs. To help you determine what is best, below are the advantages and disadvantages with each data type:
- Objects contain detailed attributes
- May be edited, queried, and deleted
- Available online or offline
- Large datasets will bog down the device
- Unique symbology must be applied using data dictionaries
- Difficult to use for displaying rich cartographic content
The following file types can be uploaded as MapItFast objects: Shapefile, KMZ, or GPX.
- Useful for overlaying different data types on top of any basemap
- Can be activated in any MapItFast project
- May be controlled through user permissions
- Can be used with larger datasets
- Can be uniquely colored and labeled on an attribute
- Available online or offline
- Displayed layers cannot be queried
- Attribute identification is limited to labeling on one attribute and coloring on another
- Labels may appear jumbled or get cut off due to the rasterization and tiling of the layersets. This is most predominant in line and polygon layers. If label placement is important, consider building a custom offline layerset.
- Online layers must be cached in advance if needed during offline use
Online layersets require a file in shapefile format.
Custom Basemaps and Offline Layersets
- Useful for displaying detailed cartographic data over large geographic areas
- Label placement can be customized
- Fast and responsive
- Can be very large in size (i.e. several GB); may require using an external SD card on your device
- Building offline layersets and basemaps requires third party software
- Processing time for the tile package can take anywhere from a few minutes to several days.
Offline layersets and basemaps must be processed into an MBTiles format.