lightpeak

Here is what I'm trying to accomplish.
When I set Max distance on AO to a very small value, hair renders quite fast, but then AO is incorrect of course. Is it possible to set two AO shaders one that would take only surrounding geometry for each hair into account excluding surrounding hairs and another one that would do only hair with small max distance? I'm trying to think how to have this as one shader, but can't come up with a clever solution. I can do this a two separate passes with different shaders maybe… Any input would be greatly appreciated.

On the frontage
http://www.sidefx.com/index.php?option=com_content&task=view&id=1976&Itemid=353 [sidefx.com]

I tried to find any online videos or tutorial for building, animating and shading photorealistic trees in houdini, but except couple L-System videos at CMIVFX, I could not find anything. I'm looking at comparable quality to Speedtree. Any suggestions? I know Houdini should be up to the task