I've looked all over for a post about this and I can't find any answer. I am curious as to whether the camera in After Effects culls layers outside of it's view frustum, like this: http://www.lighthouse3d.com/tutorials/view-frustum-culling/. I ask because if it does do view frustum culling then it is pointless going through my project and trimming my layers to be the exact length that they are within the camera's field of view to speed up performance and render time. I am currently working on a project where my camera pans slowly across many photographs and I spend my time trimming the layers when they are not visible by the camera which I believe saves time on rendering and processing, however, it takes me a long time to do manually. I know that every game engine does this to save resources, it would be a shame if after effects didnt do it. But does anyone actually know?
There is nothing to cull because AE's layers are not geometry-based. They are buffers that are transformed and mangled with effects, which is, for the most part, a completely different thing. AE is smart enough to not load layers outside the comp window into memory and it can also detect layers with 0% opacity and not load them just as it respects of course the layer visibility, but there is no further optimization like slicing layers into tiles and hiding the invisible ones or whatever.