Getting TF2 entities to show up in Garry's Mod

Having made a really spiffy TF2 map and needing some good flythrough footage, I loaded up the map in GM and used the catmull-rom plugin. Looks great.

Only problem is, none of the TF2-specific entities in the map load up, and it looks odd and really bare.

Is there any way to get the map to load in Garry’s mod with the TF2 specific entities?

(if you want to see what the video looks like, you can watch it on youtube here)