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QGIS

QGIS is an Open Source Desktop GIS platform. Since its inception in 2002, it's become a staple in the geospatial data stack. Download QGIS here.

Fused UDFs can be configured to return raster tile and vector data in formats that QGIS can load. The QGIS User Guide describes how QGIS handles different data types. This walkthrough shows how to generate URL endpoints to easily load data into QGIS.

1. Generate a signed URL for a UDF​

First, create a UDF and generate an HTTP endpoint.

2. Load data into QGIS​

QGIS supports loading data from UDFs called as both File and Tile.

Raster Tiles (Streamed data)​

Dynamically render XYZ raster tiles on the QGIS map.

As an example, the "Sentinel Tile Example" public UDF returns an XYZ tile URL of NDVI from the Sentinel dataset. Create a new instance of it on your workbench, generate a shared URL, then modify the URL query parameters:

  • Set dtype_out_raster to png.
  • Set replace the values after /run/tiles with the /{z}/{x}/{y} template.
  • Set UDF parameters as needed.

For example:

https://www.fused.io/server/v1/realtime-shared/da71c7bf79376f2e88b37be9ecd2679f2e40a5b79f9b0f2c75e7ea9a3f0c5171/run/tiles/{z}/{x}/{y}?dtype_out_raster=png

Open the modal to create a new raster XYZ layer by right-clicking: XYZ Tiles -> New Connection. Now paste the UDF URL in the URI field and configure the layer as shown.

File

This should render the raster output tiles on the map. This example shows NDVI in the area surrounding Santa Rosa Island, off the coast of Southern California.

File

Note that the QGIS client is liable to timeout errors if it encounters a high number of concurrent requests and might show a warning similar to this one. Issues generally resolve after waiting some time.

2024-04-12T12:10:06     WARNING    Network request https://www.fused.io/server/v1/realtime-shared/da71c7bf79376f2e88b37be9ecd2679f2e40a5b79f9b0f2c75e7ea9a3f0c5171/run/tiles/14/2722/6554?dtype_out_raster=png timed out`

Vector Tiles (Streamed data)​

Load large vector files as tiles. This is helpful to stream Tile UDF

You can follow QGIS instructions here

We'll use the Overture Maps Example public UDF as an example:

  • In the "Share page" for the UDF, set dtype_out_vector to mvt:
https://www.fused.io/server/v1/realtime-shared/UDF_Overture_Maps_Example/run/tiles/{z}/{x}/{y}?dtype_out_raster=png&dtype_out_vector=geojson

(Make sure the tiles are set to {z}/{x}/{y}? so QGIS can load the data as you pan around)

QGIS setting up vector tiles

  • In QGIS create a new "Vector Tiles" layer by right-clicking: Vector Tiles -> New Connection. Now paste the UDF URL in the URI field and configure the layer as shown.
  • Load the layer in QGIS and stat panning around!

QGIS vector tiles loaded

Vector File (Small file)​

Load vector data onto the QGIS map.

As an example, the "Single Route" public UDF returns a composite vector line of driving directions between an origin and destination locations. Create a new instance of it on your workbench, generate a shared URL, and then modify the URL query parameters:

  • Set dtype_out_vector to geojson.
  • Set UDF parameters as needed.

For example:

https://www.fused.io/server/v1/realtime-shared/4f8fe6b81811ce011d7045b9fffbcfb43663637a4c626955821566fe62e6fb57/run/file?dtype_out_vector=csv&lat_start=37.7954425&lng_start=-122.3961885&lat_end=37.8592408&lng_end=-122.5349321

Open the modal to create a new vector layer by clicking: Layer -> New Layer -> Add Vector Layer. Now paste the UDF URL in the URI field and configure the layer as shown.

File

This should load the data and render it on the map.

File

Note that QGIS might cache the response of endpoint calls, which means UDF changes might not propagate immediately.