onRegion with KML like google earth

has anybody had experience using events such as onRegion in cesium and/or would be able to point me in the right direction if I want to try implement this type of functionality myself.

thanks in advance

Regions are on the Roadmap for support in Cesium. We plan on getting to it, but we don’t have a set date yet.

You can follow this issue on GitHub to know when it’s done. https://github.com/AnalyticalGraphicsInc/cesium/issues/873