Clickable world map

I found out about cesium very recently and I should say I liked it very much. I am planning on using it for my own project which involves functionality like shown here. . In my case instead of the whole world, its only related to the US Map with clickable US states and counties. I am thinking of how to approach this particular issue. Should I be using czmls for the map. Also please throw some light on how I should be able to recreate those light rays originating from one country and jumping into another country.

Kamal Reddy,

From under the shadow of the Sun.