Fix camera zoom issue where the camera can get lost under the surface of the earth.
Fix camera zoom issue where the camera can get lost under the surface of the earth.

YonatanKra/cesium,esraerik/cesium,ggetz/cesium,josh-bernstein/cesium,geoscan/cesium,CesiumGS/cesium,omh1280/cesium,kiselev-dv/cesium,NaderCHASER/cesium,jason-crow/cesium,oterral/cesium,kaktus40/cesium,omh1280/cesium,AnimatedRNG/cesium,aelatgt/cesium,CesiumGS/cesium,esraerik/cesium,emackey/cesium,oterral/cesium,likangning93/cesium,aelatgt/cesium,emackey/cesium,wallw-bits/cesium,NaderCHASER/cesium,kiselev-dv/cesium,ggetz/cesium,denverpierce/cesium,likangning93/cesium,hodbauer/cesium,kaktus40/cesium,esraerik/cesium,denverpierce/cesium,kiselev-dv/cesium,soceur/cesium,esraerik/cesium,omh1280/cesium,ggetz/cesium,AnimatedRNG/cesium,CesiumGS/cesium,YonatanKra/cesium,ggetz/cesium,AnimatedRNG/cesium,hodbauer/cesium,CesiumGS/cesium,wallw-bits/cesium,soceur/cesium,wallw-bits/cesium,YonatanKra/cesium,oterral/cesium,likangning93/cesium,omh1280/cesium,jason-crow/cesium,emackey/cesium,denverpierce/cesium,likangning93/cesium,josh-bernstein/cesium,jason-crow/cesium,aelatgt/cesium,denverpierce/cesium,CesiumGS/cesium,NaderCHASER/cesium,aelatgt/cesium,AnalyticalGraphicsInc/cesium,hodbauer/cesium,AnalyticalGraphicsInc/cesium,likangning93/cesium,progsung/cesium,jasonbeverage/cesium,jasonbeverage/cesium,emackey/cesium,soceur/cesium,geoscan/cesium,AnimatedRNG/cesium,jason-crow/cesium,progsung/cesium,kiselev-dv/cesium,YonatanKra/cesium,wallw-bits/cesium