how to extract the multipatch geometry of my featureLayer and get the centroid 's coordinate using arcGIS runtime version 100.1

[ManelKEDDAR]

Hello every one ,

I'm trying to visualize an ArcGisSceneLayer  on my ScenView and point the view of the SceneView on the geometry's centroid coordinate of my ArcGisSceneLayer but don't know how to retrieve that  ? any one have an idea about that ? didn't find useful things neither on the guide nor on the API References of the WPF .Thanks in advanced i joind my (.lpk) to have an idea about my data 

thanks

cheers