I feel like I'm probably missing something obvious. I have an MP4 video that I imported into After Effects, and then used the paint tool on top of for a sort of rotoscoping effect. I can preview the video with the effects perfectly in the composition/layer window, but neither the video or the effects will ever preview in the small project window in the top left of the screen. When I render the composition, it comes out completely black, just like in the project preview. What should I do to fix this?
You set the only layer in your composition to a guide layer. If you don't know how to turn that on or off type "guide layer" in the search help field at the top right corner of the app and read up.
Ah I see. Thank you so much!