Map performance with complex shape files

[Steve]

Hi,

I need to be able to display census tract shape date from the Census Bureau. I'm able to read in the shape file just fine but once I do the performance to drag and pan the map goes down. 

Any suggestions on how to improve performance? I've tried simplifying the shape data and while it helps a little its still slow.

If that's just the nature of the beast is there a way to clear out all the shape data from the visualization layer? Hiding the layer doesn't seem to restore the performance?

 

[Petar Mladenov]

Hi Steve,

You can try setting UseBitMapCache = False on the VisualizationLayer. If this does not speed up the performance, probably you have thousands of points and this is critical for the overall WPF rendering engine. How much items / points do you load ?

Regards,
Petar Mladenov
Telerik

[Steve]

Thanks for the reply!

 I did some digging and found a different example that recommended using a Virtualization source to read the map shape data in.

I also set UseBitMapCache=false as you recommended and I'm not noticing much of a difference.

Currently I'm loading two different census tract shape files, I'm not sure the number of points but they are adding 2,061 different polygons to the map. 

[Petar Mladenov]

Hello Steve,

2000+ Polygones * (4-5-6-7) Points in each polygon means 10-20 000 Points which is too much for the WPF Rendering engine. 

The best way to improve the performance in scenarios with so many points / shapes is to use Virtualization.
Check out the Map Shape Data virtualization help article and set up an IMapItemsVirtualizationSourcesource in your project.

Could you also please elaborate more on the idea for clearing all the shapes data ? We are a bit confused what you have in mind.

Regards,
Petar Mladenov
Telerik