Hehehe - sorry to wake the thread up again, but this may be the first page people find if they're looking for this sorta thing.

I've written an unbelievably hacky script to get camera/object animations out of Houdini and into AE. It's cludgy, and everything's hardcoded, but it works, and it's simple enough to understand and tweak to your needs:

script: https://gist.github.com/howiemnet/9252ec2fd15c51e4f708c3a535f194fc [gist.github.com]

usage: create a new toolbar button, copy this script into it. Adjust the constants at the start to taste (like, choose the cam/object you want to grab the animation from etc). Run the script. It'll create a text file in your home folder: open it, copy it to the clipboard. Now you can paste it onto a camera (or other 3D layer) in After Effects. Woo… keyframes. Up to you to set up the AE camera (focal length/aperture) the same way as it is in Houdini, mind, but that's just a couple of numbers to copy over.

quick example: landscape/particles in Houdini, distant sky/stars and emitter lensflare in AE:
https://vimeo.com/227242596 [vimeo.com]