AO and particle systems

I have this model I’m animating for a project:

The problem: I’m hoping to be able to use AO for this project. However, naturally, the various particle systems providing the hair for the model make rendering times unacceptable. Is there a way that I could apply the hair in post using renderlayers and nodes somehow to resolve this? Is there any other workarounds anyone would care to share?

EDIT: By disabling traceable and shadbuf I was able to get a very significant reduction in render time, acceptable, but barely. But how much will this affect the final result? I’m not looking for extraordinary lighting detail on the hairs, but I also don’t want to end up with something that doesn’t look right, or natural. Only one sequence will be shot that has the insect’s head in full frame (at HD resolution). Perhaps a shadbuf might then be needed? Thoughts anyone?

:frowning: It seems AO may not be worth the trouble. At the rates i’m going it would take a non-stop 2 weeks to render all the frames I need using the 3 workstations I have (and they’re very nice workstations too) Unfortunately I don’t have that kind of flexibility on time.

AO was an easy way to get this scene lit nicely and realistically. Plus I really liked the grain that it produced (even though i know a lot of people don’t).

I’ve read a lot in the past on lighting with blender, but perhaps some might know of some useful information on the subject. (I tried faking Global Illumination, but without a magnitude of light dupliverts, I didn’t get very good results. And even then results weren’t so great. And at that point render times were nearly as long as AO.)

Also, anyone know a way to fake that grain, (kinda like a film grain) with nodes or something?