I would like to present you a very nice évolution of my GAO Ambient Occlusion Shader by BAO2.
He did a more complex version, with inverted AO (edge detection) and some other enhancements.
here is the link to dicover the GAO2 AO OSL SHADER !
ADDEDUM : GAO and GAO2 are updated ! Click here to see the new versions GAO1.1 and GAO2.1 !