Idk, but this is the first paper coming to my mind: https://graphics.tudelft.nl/Publications-new/2012/KRES12/paper.pdf

Your random number generator surely is bad, and you probably need some blur for the noise. 

Thanks guys!!                                                                                  …

In this post, you will learn the magic behind Unity Ray-Traced Ambient Occlusion (RTAO).

Today, you will see:

• What ambient occlusion will do for you
• The visual superiority of Ray-Traced Ambient Occlusion (RTAO) over Screen-Space Ambient Occlusion (SSAO)

Let's get your game to look the way you always in…