Introduction Image-space horizon-based ambient occlusion [HBAO] is a technique introduced by NVidia (Louis Bavoil et al.) in 2008. I recommend checking out the following resources to find out exactly how the algorithm works, this post will build on it further: ShaderX7 – Image-Space Horizon-Based Ambient Occlusion (by Louis Bavoil & Miguel Sainz) The original Siggraph…