If you have a large scene areas might be outside C4D's default view clipping depth (useful for improving view performance with large scenes)
Open the
Help>Reference Documentation
menu and search for 'View Clipping'
cheers,
os
cheers,
Owen Sharp
Design Technology Manager
fjmt | francis-jones morehen thorp
iMac 27" i7 2.93Ghz | 32GB RAM | OS 10.10 | Since AC5