topic Re: Graphics disappear when zooming in in Qt Maps SDK Questions

Graphics disappear when zooming in

FatmaAkdemir — Fri, 28 May 2021 13:32:29 GMT

I have some Graphics (lines, circles etc.) displayed on the tiled map layer. They tend to disappear when user zooms in. What might be causing this behaviour?

Re: Graphics disappear when zooming in

JaredCaccamo — Fri, 28 May 2021 16:36:39 GMT

Hello @FatmaAkdemir ,

It seems like you are running into the max scale on the layer and once that is exceeded the layer no longer displays . For service layers, this is defined by the service, Layer::maxScale. Here is a related sample as well, min-max scale sample. Let me know if I am on the right track.

Sincerely,

Jared

Re: Graphics disappear when zooming in

FatmaAkdemir — Wed, 02 Jun 2021 06:40:27 GMT

Hi @JaredCaccamo ,

I have solved my issue by changing my graphic overlay's SurfacePlacement to Draped. It was like below:

setSceneProperties(LayerSceneProperties(SurfacePlacement::Absolute));

I changed it to:

setSceneProperties(LayerSceneProperties(SurfacePlacement::Draped));

Re: Graphics disappear when zooming in

JaredCaccamo — Wed, 02 Jun 2021 15:39:44 GMT

@FatmaAkdemir Ah I can see how this could cause some confusion in your situation. SurfacePlacement::Drapped does as you might think and drapes the symbol/graphic onto the surface itself. SurfacePlacement::Absolute is placed at the elevation specified in meters above sea level. It is also possible for that to go below the surface which if not anticipated could lead to unexpected behavior as well.

Happy to hear you solved the issue!

Re: Graphics disappear when zooming in

JaredCaccamo — Wed, 02 Jun 2021 15:41:52 GMT

@FatmaAkdemir I forgot to mention we have a sample that demonstrates all the different SurfacePlacement modes and is interactive to help show how they are different, Surface placement sample.