topic Re: Continuous Zoom? in ArcGIS JavaScript Maps SDK Questions

Continuous Zoom?

NevinFry — Tue, 10 Jul 2012 15:00:15 GMT

Hi,
I've noticed that when using touch on the map control and zooming, the map will continue to zoom after you let go, presumably to the next LOD level.
Is it possible to turn this off? Or is it possible to re-implement touch zoom to stay at the extent you are at when you let go?

Related, is it possible to give the map an extent that doesn't correspond to an integer LOD and have it stay there? Or will it always fit to an integer LOD?

Thanks

Re: Continuous Zoom?

StephenLead — Wed, 11 Jul 2012 00:24:48 GMT

Hi James,

Assuming that your map has a tiled/cached layer, then it's only possible to zoom to an integer zoom level. If you do need an "infinite zoom" range, you'll need to use Dynamic or Feature layers only.

Steve

Re: Continuous Zoom?

AdrianMarsden — Fri, 14 Sep 2012 11:10:20 GMT

Steve - do you know if there are any plans to change this? I'd love to have a map with infinite zoom, but still use a tiled service at the higher zoom levels, I've got round this by adding the map cache into th MXD I define the service with, but this isn't ideal.

Cheer

ACM

Re: Continuous Zoom?

JeffPace — Fri, 14 Sep 2012 18:08:58 GMT

infinite zoom and tiles are mutually exclusive, by definition. You cannot have both.

Re: Continuous Zoom?

StephenLead — Sat, 15 Sep 2012 04:24:41 GMT

infinite zoom and tiles are mutually exclusive, by definition. You cannot have both.

Jeff,

That's true right now - but it would make a good enhancement request to have this ability.

The Google Maps app on an iPhone does this. You can adjust the zoom level "infinitely" using pinch/zoom - the tiles get marginally bigger or smaller, until you cross to a new scale threshold, whereafter the display changes to show the new set of tiles.

Conceptually, it seems that the ArcGIS JS API could be modified by Esri to do the same thing. There could be a "useInfiniteZoom" option when using a tiled basemap layer, for whether to restrict zooming to discrete levels, or allow any zoom level.

Someone from Esri might have a response as to whether that's feasible and in the pipeline.

Steve

Re: Continuous Zoom?

AdrianMarsden — Sat, 15 Sep 2012 07:26:54 GMT

Indeed - check out http://chawke.co.uk/infitnity_and_beyond.html for what I mean.

The data for the initial extent through to the grey scale property based maps are all from a tiled service read into the MXD that generates the dynamic service. These data are all generated from Vector data, so there is a processor overhead generating it for each request. Rasterizing it and tiling it is very effective. For my internal use, these layers are just for reference, alternative, finer detailed maps are available on request.

Most of our work is done on the 1:100 to 1:1250 scale range, where I need to provide infinite zoom levels that read the fine detailed vector maps (the excellent OS MasterMap)

Having a cached service with a dynamic service and infinite zoom on the API will enable client based caching of the initial basemaps, nice slippy maps at those scales, and a nicer user experience.

Chers

ACM

Re: Continuous Zoom?

RyanMonk1 — Wed, 26 Oct 2016 03:17:38 GMT

Is there a way to implement this on the ArcGIS Online map viewer using the default basemaps?

For the data on my map I need to be able to view it at about half way between two zoom levels, the steps between the levels are too large. I noticed in Google Maps zooming using the mouse wheel increments the zoom level by 0.25, this feels about right.

Doing this in ArcGIS Desktop is simple with the Continious Zoom tool.

The only way I've found of doing this on ArcGIS Online is by using a MapService as a basemap.

Why do ArcGIS Online maps require a basemap at all? What if I don't want one?

Is there an empty/blank MapService I can use to work around this?

Re: Continuous Zoom?

RobertScheitlin__GISP — Wed, 26 Oct 2016 12:54:04 GMT

Ryan,

Look at this site for an answer:

How to Create a Blank Basemap for ArcGIS Online | GISNuts.com