Can I use the MapKit 3D model of a city, and anchor it as a child of an anchor using LiDAR geotracking? For long distance occlusion and collision purposes?
There is no integration of MapKit into the ARView. If you know the building footprint (i.e. the polygon in lat/lon coordinates) or even exact geometry anchored to a lat/lon coordinate you can transform these coordinates by placing ARGeoAnchors at a that location. If they are tracked in ARKit you get the local coordinates and can build an occlusion/collision mesh.