I got the first post about direct lighting material occlusion up on my blog. On this one I go over the commonly used micro-occlusion approach and its limitations, and I start digging into micro-shadowing as an improvement.

https://irradiance.ca/posts/microshadowing-part1/

I look at existing solutions, present a simple alternative, and setup the stage for a future post by mentioning the limitations of those micro-shadowing solutions. The post includes plots for the different micro-shadowing approaches, HLSL code, and screenshots (please forgive the programmer's art).