transfer ocean cusp attribute to extra image plane

[ollynash]

Hi Folks,

I wonder if you could give me some pointers for how to successfully transfer the OceanTools cusp attribute to an extra image plane, please?  I've added it into the shader with a parameter node (set as vector) and added it to the extra image planes list, but nothing renders, just black pixels : (  I followed the steps in this tutorial for adding custom attributes to AOVs but no success.  http://lesterbanks.com/2014/06/set-export-aovs-houdini-mantra/ 

Any ideas what I'm missing?

Thanks,

 Olly : )