This project is read-only.

How to prevent polygon from disappearing when zooming in/out

Jan 24, 2009 at 7:08 PM
Edited Jan 24, 2009 at 9:20 PM
Hi, first of all I wan't to say this is a great project. We decided to use Deepearth in our Project and I think it'll be a good decision. What I wanted to ask you guys is - I can't seem to find a way of drawing polygons which don't disappear when I zoom in/out. There were some post where you actually showed the way of preventing this to happen by using UpdateMode property but there is no anymore this options in the version i downloaded. So I need to know if I can prevent polygon disappearing when i scroll mouse - zooming.
Maybe there is a solution already here but i didn't find it.

Thanks in advance

[Edited]
Jan 24, 2009 at 9:06 PM
That enhancement was made by Rick, will be tested this comming week in the latest changeset (would love you to take a look and report bugs as well) and be part of a Version 1.1 release when it is ready.
Jan 25, 2009 at 12:35 AM
Edited Jan 25, 2009 at 8:23 PM
Maximus, there could be a few things that could be happening here.  First of all, if you are using the PanOnlyUpdate mode on the GeometryLayer, use one of the other 2 options.  You can read about the different modes in the post GeometryLayer Update….   Secondly, there are some know limitations in the SL rendering engine with rendering large geometry.  Take our Prototype for example.  The Equator will not render correctly beyond zoom lever 7.  The Bermuda Triangle, a much smaller geometry will render okay up until zoom level 12.  Unfortunately, I haven't heard a fix or workaround for this yet.  And lastly and most obvious, if you are using the 1.0 release from mid-December, it only supports "PanOnlyUpdate" for non-Points.  If that's your case, it's time for an upgrade.  There have been a lot of improvements since then.


Jan 30, 2009 at 10:02 AM
We also had some issues with polygons on our map. After zooming a polygon would be pinned to a wrong location, and only after a panmovement the position of the polygon would be corrected.
After using the latest codebase version, this was fixed.
Jan 31, 2009 at 9:09 PM
The problem here is: objects should not get bigger then say a couple of 10000px, if you zoom in on object as huge as bermuda triangle it gets far larger.
I think the geometry classes should clip of screen points to within these limits.
Feb 3, 2009 at 6:17 PM
Adding my comment to discussion as "Issue Tracker" comments aren't published:

We do apply a Clip region to Map which matches the size of the screen (ViewPort). So it is unfortunate the the SL engine doesn't recognize this. So I assume you know this and are suggesting we implement an alternative Clipping function to Silverlight's and prune the geometry points manually. This should solve the problem, but I first want investigate if MSFT is planning to fix the rendering engine to either render the larger shapes or respect the already applied clipping region in SL3.

If anyone has any insight into whether the SL rendering engine will address any of this in SL3, please chime in.  Thanks.