I add one polygon, which is about 10km wide and high, and consists of around 20 points. I add it to a VisualizationLayer and zoom in, and at zoom level 17 the application pretty much hangs (extremely slow update). When this happens, the desktop also becomes extremely slow. The polygon is a PolygonData object. This problem does not occur if I zoom in to a location outside the polygon.
It does not matter if I add it to the Items collection or if I use virtualization, the result is same.
9 Answers, 1 is accepted
Recently we encountered similar behavior and we logged it in our feedback portal. Basically, the zooming functionality of the map consumes high amount of memory when the VisualizationLayer is used and its items are in the viewport during zoom-in. This could lead to a slower performance on some machines. To avoid this you can consider using InformationLayer instead of VisualizationLayer.
Another, possible reason for this could be the complexity of the shape or the amount of shapes in the viewport. The more complex (the more points it has) the shape is, the more time will be required by the map to render it.
Please let me know if you need any further assistance on the matter.
Regards,
Martin
Telerik
Rank 1
Thanks for the suggestions, but none of them solves my problem. I use the Visualisation layer with item virtualisation. I guess I could try the VirtualisationLayer instead, but isnt the VisualisationLayer the best layer to use ( new engine, etc).
I get this problem with a plain rectangle in an empty layer (see below), so it has nothing to do with number of points:
<telerik:VisualizationLayer Name="routesVirtLayer" RenderWhileMotion="True" AutoHighlightMapShape="False">
<telerik:VisualizationLayer.ZoomLevelGridList>
<telerik:ZoomLevelGrid MinZoom="11" />
</telerik:VisualizationLayer.ZoomLevelGridList>
<telerik:RectangleData Location="60,15"
Height="0.5"
Width="0.5">
<telerik:RectangleData.ShapeFill>
<telerik:MapShapeFill Fill="#6FDFEFFF"
Stroke="Blue"
StrokeThickness="2" />
</telerik:RectangleData.ShapeFill>
</telerik:RectangleData>
</telerik:VisualizationLayer>
​
Indeed, the VisualizationLayer is the recommended engine for displaying items on the map. In compare to the old visualization engine (InformationLayer, VirtualizationLayer and DynamicLayer) the VisualizationLayer has improved performance and several additional features - as built-in selection and async shape file readers. However, the new layer has few known issues which might lead to unpleasant results in some scenarios. As I understand from your description the experienced memory drop is caused by the issue that I referenced in my last reply. I am afraid currently there is no workaround for this, and if you want to avoid it you can use the VirtualizationLayer. Please give it a try and let me know if it works for your scenario.
Regards,
Martin
Telerik
Rank 1
When zooming in at zoom level 17 or higher, the disk is working very much, so either its as you say with increased memory and it uses virtual memory (swap), or something else is going on. Either way, the computer pretty much halts for a few seconds when this happens.
I could try with VirtualizationLayer for now, as long as the bug is fixed in the next coming release (we won't deliver anything to customer for a couple of months anyway).
/Magnus
I hope this VirtualizationLayer will be helpful for your scenario. As for the memory issue, currently, its fix is not included in our planning so I cannot give you a time frame in which release it will be fixed. However, you can vote for the item in the feedback portal. The more votes an item (request, bug report) has, the bigger is the chance for its priority to be increased and to be included in our planning.
If you have any further questions we will be glad to assist you with them.
Regards,
Martin
Telerik
Rank 1
I certainly hope this gets fixed, because the map control becomes pretty useless when you cant zoom in to level 17 or deeper. Btw, the same bug is there for polylines (and probably paths).
/Magnus
We have the issue in mind but I am afraid that we cannot bind to a time frame for its fix.
Can you please try to set the project's Platform to x64 and see if the issue still occurs? This could resolve the issue and it will give us more information about our investigation. Thank you for the cooperation.
Regards,
Martin
Telerik
Rank 1
Changing to x64 (or x86) made no difference, and I tried with Release and running outside of debugger.
The "System" activity in the task manager is interesting though, see screenshot. This happens when you get to zoom level 17+ and looks the same in x64 and x86. Virtual memory thrashing?
Btw, Im running Windows 8.1 with 16Gb of memory and i7 CPUs.
Thank you for the additional information. We are not aware what is causing this yet, but as soon as we start working on the issue we will update the status of the item in the feedback portal.
Regards,
Martin
Telerik