Layers of cached map service not visible at their maximum scale

Question

Hi everyone,

I have a cached map service on ArcGIS Portal with layers that are supposed to be visible from a maximum scale of 1:7,501.

The maximum cached scale of the service is 1:6,400.

From what I understand, there shouldn’t be any reason why the layers wouldn’t be visible at the 1:7,501 scale.

However, in both the ArcGIS Enterprise Map Viewer and ArcGIS Pro, the layers of the serviceonly become visible starting at a scale of 1:9,051.

I’ve also enabled resampling, but that hasn’t helped. It feels like the service is misinterpreting the layers’ scale settings.

Am I missing something here? Please excuse the German in the screenshot.

Best regards,

Andi

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AndreasGrimmLHM · Answer

Hi Calvin, thanks for the reply!

This is what the scales look like in ArcGIS Server Manager:

I published and cached the service manually using these settings in ArcGIS Pro (excuse the German):

Despite the layers of the service having a maximum scale of 1:7501, I have to use the same tile schema as a vector tile layer I want to combine my cached layer with - that's why the maximum cached scale is 1:6400 instead of 1:7501.

CalvinHarmin · Answer

This is not a complete answer, but a starting point - and I could be wrong - but I have a feeling this what's happening:

Cached tiles by their nature have to use a zoom level index. This is hard-coded at the time of publishing, and I don't think you can modify it after. So the resulting zoom levels you experience (how many, what the scales are at each zoom level) really depends on settings during publishing. NOTE: This is not the same as the scale settings specified in ArcGIS Pro for any given layer. So if you can share exactly how you created the service, that can lead to recommendations for modifying those settings for republishing. ArcGIS Pro is not always very 'smart' in the way it chooses the default index or zoom level options for you during publishing.

I believe one way to validate the limitations of your service is by checking the service's REST endpoint and looking at the scale values shown there. Example below of a Vector Tile service but other cached tile REST attributes might be similar.