topic Re: dynamic layer transparency in ArcGIS API for Flex Questions

dynamic layer transparency

BryanWestphal — Mon, 09 Aug 2010 18:58:10 GMT

I have an issue with a dynamic polygon layer not being transparent (set to 50% in arcmap) in my flex application. I have the image output of the dynamicservicelayer as png24. Attached is an image of what it looks like in my application. When in arcmap, the buffers are transparent. Any ideas or comments would be appreciated.

thanks for your time.

Re: dynamic layer transparency

DasaPaddock — Mon, 09 Aug 2010 19:02:20 GMT

Try setting alpha on the layer to 0.5.

Re: dynamic layer transparency

HessCorporation — Tue, 10 Aug 2010 10:03:13 GMT

It's better to set the transparency in Flex rather than ArcMap.

Leave the layer as 100% in ArcMap then go into the <ArcGISDynamicMapService/> tag and set the alpha to 0.5.

Re: dynamic layer transparency

BryanWestphal — Tue, 10 Aug 2010 18:25:18 GMT

that is what i have done in the mean time, but that also reduced the alpha of the other features that i have in my dynamic layer, such as my parcel data set, and it makes it tough to see then.

shouldn't the alpha settings in ArcMap come through like the rest of the symbology?

Re: dynamic layer transparency

DrewDowling — Tue, 10 Aug 2010 19:36:34 GMT

My limited understanding of this is that when the server creates an image for a dynamic map service the alphas for a layer are only relative to other layers in the same image at creation time. The image itself, once created, has only an overall alpha, this is controlled by Flex.

I don't think there is any way to control the alphas of individual layers using flex unless you create a service for each layer.

I could be wrong on all of this.

Re: dynamic layer transparency

DasaPaddock — Thu, 04 Nov 2010 20:53:45 GMT

Bryan,

You should get the behavior you're looking for if you publish an optimized msd and request png32 images. If you do this, then the exported image should maintain transparency for each pixel's alpha channel.

Re: dynamic layer transparency

JasonLevine — Thu, 03 Feb 2011 15:58:42 GMT

You should get the behavior you're looking for if you publish an optimized msd and request png32 images. If you do this, then the exported image should maintain transparency for each pixel's alpha channel.

Dasa,
Thanks for this tip! I usually set my imageFormat to png24 and I always wondered why the layer transparencies I set in my mxd never got represented in the service.

-Jason