A greebled torus, with AO. Chevron one encoded!
This SSAO is based on Nutty Software SSAO demo.
The segments are independent geometries, built from bent box geometries. I tried cylinders using the theta parameter, but the resulting meshes are no capped.
The main shader creates a color buffer, an eye-space normal buffer and an eye-space position buffer. The SSAO shader takes normal and position and creates an occlusion buffer. A shader combines the color and the ao, and a final shader performs FXAA, vignetting and noise.