You use fraps too record and you use the devmode command to fly around your level with the
debug_camera_save
debug_camera_load
Now you can fly around your map while holding down on your middle mouse button and use the WASD keys to move, and R and F to go up and down, scrolling the wheel down makes you go faster, and uop make syou go slower.
Hope that helps, to use devmode right clikc your shortcut for CE and put this in your target " -console -devmode" (space before the 1st - and no ")