Protect Cesium from crashing when the camera goes through terrain.
Protect Cesium from crashing when the camera goes through terrain.

jasonbeverage/cesium,likangning93/cesium,likangning93/cesium,YonatanKra/cesium,josh-bernstein/cesium,kaktus40/cesium,CesiumGS/cesium,CesiumGS/cesium,AnalyticalGraphicsInc/cesium,YonatanKra/cesium,progsung/cesium,likangning93/cesium,geoscan/cesium,CesiumGS/cesium,AnalyticalGraphicsInc/cesium,kaktus40/cesium,progsung/cesium,YonatanKra/cesium,likangning93/cesium,josh-bernstein/cesium,YonatanKra/cesium,likangning93/cesium,jasonbeverage/cesium,CesiumGS/cesium,CesiumGS/cesium,geoscan/cesium