Showing a FlowRenderer for a COG image

JonathanDawe_BAS — Fri, 13 Feb 2026 12:32:04 GMT

I’ve been experimenting with ImageryTileLayer + COG data in the JavaScript Maps SDK in order to hopefully encode and show flow. My COG here (derived from NOAA GFS WAVE data): https://jonnydawe.github.io/.well-known/wave_uv_cog.tif encodes U/V components (Band 1 = U, Band 2 = V). The data itself works fine, but out of the box it is not possible to get a flow renderer to work without some tweaks.

The issue is highlighed in the flowRenderer docs: "the source type of your raster dataset must be Vector-UV or Vector-MagDir" I notice that my COG is treated as generic data type, not vector-uv, so the renderer does not work....

However... I notice that I can just override the datatype by setting its keyProperties (albeit on an internal private property...)

imageryLayer.load().then(() => { const rasterInfo = imageryLayer.raster.rasterInfo; const existingKeyProperties = rasterInfo.keyProperties ?? {}; rasterInfo.keyProperties = { ...existingKeyProperties, DataType: "Vector-UV", }; console.log("RasterInfo dataType:", rasterInfo.dataType); });

The end result is a flow renderer working with a COG: https://codepen.io/Jonathan-Dawe/pen/myEoboQ?editors=1000

Is there a way to get the layer to internally identify the COG as a Vector-UV layer without having to override the internal property like this?

Re: Showing a FlowRenderer for a COG image

JonathanDawe_BAS — Fri, 13 Feb 2026 15:37:50 GMT

I've discovered that if I set it in the metadata of the COG, "DataType": "Vector-UV", then it it also works! However I still get an error about it not matching the required type because I have more than two bands!

topic Showing a FlowRenderer for a COG image in ArcGIS JavaScript Maps SDK Questions

Showing a FlowRenderer for a COG image

Re: Showing a FlowRenderer for a COG image